US20080233954A1

US20080233954A1 - Method And System For Processing Results Derived From Detecting Channels Suitable For FM Transmission In An Integrated FM Transmit/Receive System

Info

Publication number: US20080233954A1
Application number: US11/832,858
Authority: US
Inventors: Brima Ibrahim; John Walley; Scott Bibaud; Bojko Marholev; Prasan Pai; Siukai Mak; Asif Grushkevich
Original assignee: Broadcom Corp
Current assignee: Avago Technologies International Sales Pte Ltd
Priority date: 2007-03-19
Filing date: 2007-08-02
Publication date: 2008-09-25
Also published as: US8208886B2; US8027641B2; US20080233911A1; US20120021706A1; US20080233882A1; US20080232447A1; US7925220B2; US20110183628A1; US7917115B2; US20080233881A1; US8391810B2; US20100279633A1; US7586378B2; US20080233883A1; US7792502B2; US20080233869A1; US20080233890A1; US20110171916A1; US20080232523A1; US7983617B2

Abstract

A method and system is provided for enabling communication, where a FM radio system including an integrated FM radio transmitter and FM radio receiver may use an in-band FM or out of band transmitter to communicate a dynamically generated list with alternate local FM channels to an in-band or out of band receiver of another FM radio device with a FM radio receiver. The generated list of local FM channels may be ranked according to the least neighboring channel interference and may be selected for tuning the FM radio device. The FM radio system and the FM radio device may both scan to generate a substantially matched list of local FM channels. In response to detecting a new signal of a transmitted channel by the FM radio system, the FM radio device may tune to the same channel using an open loop, closed loop or semi-open loop method.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to, claims priority to, and claims the benefit of U.S. Provisional Application Ser. No. 60/895,665 filed on Mar. 19, 2007.
This application also makes reference to:
U.S. application Ser. No. 11/755,395 filed on May 30, 2007;
U.S. application Ser. No. ______ (Attorney Docket No. 18371US02) filed on even date herewith.
Each of the above stated application is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to wireless communication. More specifically, certain embodiments of the invention relate to a method and system for processing results derived from detecting channels suitable for FM transmission in an integrated FM transmit receive (FM Tx/Rx) system.

BACKGROUND OF THE INVENTION

Frequency Modulation (FM) is a form of modulation in wireless communication which represents information as variations in the instantaneous center frequency of a carrier wave. Frequency modulation was chosen as a modulation standard for high frequency signal transmission. A plurality of FM frequencies (channels) each separated by a frequency spacing may be broadcasted by a transmitter tower, a radio station or by a transmitting FM radio device.
A FM radio receiver of a FM radio includes a tuner with a tunable local oscillator (LO) may scan or search for broadcasted local FM frequency channels. Scanning may be performed by tuning the LO across the full tuning range of the LO or sweep the LO back and forth over a narrower tuning range to search for a signal of interest such as a FM channel. A FM channel may be detected or tuned if the FM radio receiver may successfully process a signal of sufficient signal amplitude, and/or the tuner may be able to establish an intermediate frequency (IF) signal that may be substantially the same or close to a defined offset of the FM radio receiver. When signals of two similar frequencies (from different broadcast stations or a neighboring broadcasting device) are received by the FM radio receiver, the FM radio receiver may process the stronger of two signals being broadcasted on the same frequency.
Radio Data System (RDS) or Radio Broadcast Data System (RBDS) standard format may be transmitted as a sub-carrier on the FM signals. The RDS/RDBS data format may contain information such as alternate frequencies of the broadcast station, the clock time, program identification with known channel frequency, channel spacing, station ID, country code or country identity, regional links and Enhanced Other Networks (EON) etc.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

A method and system for processing results derived from detecting channels suitable for FM transmission in an integrated FM transmit receive (FM Tx/Rx) system, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
These and other advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary FM radio system with an integrated FM radio transmitter and FM radio receiver communicating to a FM radio transmitter, in accordance with an embodiment of the invention.

FIG. 2 is a block diagram of an exemplary FM radio system with an integrated FM radio transmitter and FM radio receiver dynamically communicating FM channels to another FM radio device having an FM radio receiver, in accordance with an embodiment of the invention.

FIG. 3A is a diagram illustrating a dynamic scanning process of a FM radio system with an integrated FM radio transmitter and FM radio receiver in a FM frequency spectrum, in accordance with an embodiment of the invention.

FIG. 3B is a diagram illustrating a dynamic local FM channel tuning by a FM radio system with an integrated FM radio transmitter and FM radio receiver based on a ranked local FM channel list or based on user intervention, in accordance with an embodiment of the invention.

FIG. 4 is an exemplary diagram of a FM radio system with an integrated FM radio transmitter and FM radio receiver on a Chip (SOC) with an integrated Bluetooth (BT) or Out Of Band (OOB) transceiver scanning local FM channels, in accordance with an embodiment of the invention.

FIG. 5A is an exemplary diagram illustrating dynamic detection of occupied or unoccupied local FM channels, in accordance with an embodiment of the invention.

FIG. 5B is an exemplary diagram illustrating extraction of unoccupied local FM channels available for transmission, in accordance with an embodiment of the invention.

FIG. 5C illustrates an exemplary process of generating and ranking of local FM channels list available for transmission, in accordance with an embodiment of the invention.

FIG. 5D is an exemplary diagram illustrating dynamic processing of alternate local FM channels for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention.

FIG. 5E is an exemplary diagram illustrating dynamic detection of occupied or unoccupied local FM channels when channel distribution changes, in accordance with an embodiment of the invention.

FIG. 5F illustrates an exemplary dynamic process of updating the local FM channel list for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention.

FIG. 5G is an exemplary diagram illustrating dynamic processing of updated alternate FM channels for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention.

FIG. 5H illustrates an exemplary simultaneous scanning of a FM radio system with an integrated FM Tx/Rx (as a source device) and another FM radio device with an FM receiver (as a sink device) to generate a substantially matched local FM channels list for available local FM transmission selection, in accordance with an embodiment of the invention.

FIG. 5I illustrates an exemplary tuning of another FM radio device with an FM radio receiver to a selected local FM channel in response to a detection of a sudden increase of RSSI level of a channel signal, in accordance with an embodiment of the invention.

FIG. 6A is a flow chart that illustrates exemplary steps for processing results derived from detecting channels suitable for FM transmission, in accordance with an embodiment of the invention.

FIG. 6B is a flow chart that illustrates exemplary steps for open loop, closed loop or semi closed loop tuning of selected local FM channel, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and system for processing results derived from detecting channels suitable for FM radio transmission in an integrated FM radio transmit and receive (FM radio Tx/Rx) system. In an aspect of the invention, an FM radio system may comprise an integrated FM radio transmitter and FM radio receiver (FM radio Tx/Rx) to scan and detect local FM channels to generate a local FM channel list available for FM transmission to another FM radio device. The another FM radio device may comprise an FM radio receiver.
In a dynamic environment with changing channel distribution and changing neighboring channel interferences, the integrated FM radio Tx/Rx system may dynamically update the FM channel list to select the most suitable or preferred local FM radio channel for FM radio transmission to another FM radio receiver. The FM radio receiver may tune to the same preferred or selected local FM channel transmitted by the integrated FM radio Tx/Rx system through open loop, closed loop or semi closed loop tuning.
In an embodiment of the invention, the integrated FM radio Tx/Rx system may comprise an integrated out-of-band (OOB) transmitter and the other FM radio device may comprise a FM radio receiver and an OOB receiver. The integrated FM Tx/Rx system may transmit a ranked local FM channel list to the FM radio receiver through OOB signals and the FM radio receiver may tune to a selected channel from the ranked local FM channel list. In another embodiment of the invention, both the integrated FM Tx/Rx system and the FM radio receiver may comprise an OOB transceiver to enable bidirectional communication. The open loop tuning may comprise user intervention where the user may tune the FM radio receiver to the preferred local FM channel following an updated channel list information from the integrated FM Tx/Rx system. In an embodiment of the invention, such updated channel list information may be communicated utilizing RDS/RDBS data to the user in the form of visual text display, text to speech audio format or a combination of visual and audio notifications. The user may tune the FM radio receiver to the suggested transmitted channel, or the user may tune to the next alternate FM channels available for transmission.
The closed loop tuning may comprise automatic tuning without user intervention where the FM radio receiver may tune to the same preferred local FM channel or to an alternate FM channel in response to receiving a ranked local FM channel list from the integrated FM Tx/Rx system. In an embodiment of the invention, both the integrated FM Tx/Rx system and the FM radio receiver may scan the FM spectrum to generate a substantially matched local channel list. Upon confirmation of the substantially matched local channel list, the integrated FM Tx/Rx system may transmit an available FM channel signal to the FM radio receiver.
The FM radio receiver may tune to a channel in response to detecting a new signal. In an exemplary embodiment of the invention, the FM radio receiver may detect a new signal based on a sudden RSSI level increase of the transmitted available FM channel signal and may subsequently tune the FM radio receiver to the same transmitted FM channel in response to such detection. In another exemplary embodiment of the invention, the FM radio receiver may indicate that a new signal (broadcasted by the integrated FM Tx/Rx system to the FM radio receiver) may be introduced to the FM spectrum based on monitoring a change in the Bit Error Ratio (BER) of the RDS/RDBS data. The transmitted FM channel may comprise the least neighboring channel interferences. The semi closed loop tuning method may comprise combining both closed loop and open loop tunings. In an embodiment of the invention, the open loop tuning may involve user's intervention.
FIG. 1 is a block diagram of an exemplary FM radio system with an integrated FM radio transmitter and FM radio receiver communicating to a FM radio transmitter, in accordance with an embodiment of the invention. Referring to FIG. 1, there is shown an FM radio transmitter 102, a plurality of FM radio systems, each with an integrated FM radio transmitter and FM radio receiver such as a cellular phone 104 a, a smart wireless hand held device 104 b, a computer 104 c, and an exemplary FM and Bluetooth-equipped device 104 d. The FM radio transmitter 102 may be implemented as part of a radio station or other broadcasting device, for example. Each of the cellular phone 104 a, the smart wireless hand held device 104 b, the computer 104 c, and the exemplary FM and Bluetooth-equipped device 104 d may comprise a single chip 106 with integrated FM and Bluetooth radios for supporting FM and Bluetooth data communications. The integrated Bluetooth data communication may be included as an optional feature in the exemplary FM radio systems. The FM radio transmitter 102 may enable communication of FM audio data to the plurality of FM radio systems shown in FIG. 1 by utilizing the single chip 106. The plurality of FM radio systems, each with an integrated FM radio transmitter and FM radio receiver 104 a to 104 d in FIG. 1 may comprise and/or may be communicatively coupled to a listening device 108 such as a speaker, a headset, or an earphone, for example. In other embodiments of the invention, the functions of the single chip 106 may be implemented as discrete components.
The cellular phone 104 a may be enabled to receive an FM transmission signal from the FM radio transmitter 102. The user of the cellular phone 104 a may then listen to the transmission via the listening device 108. The cellular phone 104 a may comprise a “one-touch” programming feature that enables pulling up specifically desired broadcasts, like weather, sports, stock quotes, or news, for example. The smart wireless hand held device 104 b may be enabled to receive an FM transmission signal from the FM radio transmitter 102. The user of the smart wireless hand held device 104 b may then listen to the transmission via the listening device 108. In an embodiment of the invention, the wire 166 f connecting the smart wireless hand held device 104 b to the listening device 108 may function as an external antenna similar to the antenna 166 e for FM transmission and/or reception.
The computer 104 c may be a desktop, laptop, notebook, tablet, and a PDA, for example. The computer 104 c may be enabled to receive an FM transmission signal from the FM radio transmitter 102. The user of the computer 104 c may then listen to the transmission via the listening device 108. The computer 104 c may comprise software menus that configure listening options and enable quick access to favorite options, for example. In one embodiment of the invention, the computer 104 c may utilize an atomic clock FM signal for precise timing applications, such as scientific applications, for example. While a cellular phone, a smart phone, computing devices, and other devices have been shown in FIG. 1, the single chip 106 may be utilized in a plurality of other devices and/or systems that receive and use FM and/or Bluetooth signals. In one embodiment of the invention, the single chip 106 FM and Bluetooth radio may be utilized in a system comprising a WLAN radio. The U.S. application Ser. No. 11/286,844, filed on Nov. 22, 2005, discloses a method and system comprising a single chip FM and Bluetooth radio integrated with a wireless LAN radio, and is hereby incorporated herein by reference in its entirety. In another embodiment of the invention, the devices 104 a to 104 d shown in FIG. 1 may comprise an optional Global Positioning System (GPS) receiver to receive device location information.
In an alternate embodiment of the invention, the cellular phone 104 a, smart wireless hand held device 104 b, computer 104 c, and the exemplary FM and Bluetooth-equipped device 104 d may function as source devices (signal sources) to re-broadcast received signals from the transmitter 102 to one or more other sink devices (signal receptors) such as another FM radio devices with FM receivers. The single chip 106 may not be limited to integrating only Bluetooth technology, other out of band (OOB) wireless communication functions such as wireless local area network (WLAN), wireless wide area network (WWAN), cellular band or ZigBee may be integrated into the single chip 106.
FIG. 2 is a block diagram of an exemplary FM radio system with an integrated FM radio transmitter and FM radio receiver dynamically communicating FM channels to another FM radio device having an FM radio receiver, in accordance with an embodiment of the invention. Referring to FIG. 2, there is shown a FM radio transmitter 102 a, a plurality of FM and OOB equipped FM radio systems with integrated FM radio transmitters and FM radio receivers such as a cellular phone 104 e, a smart wireless hand held device 104 f, a computer 104 g, and an exemplary FM and OOB-equipped device 104 h, and another FM radio device with an FM receiver 110. The FM radio transmitter 102 a may broadcast FM channels 120 f (occupied and unavailable for local FM channel transmission) to the plurality of FM radio systems each with an integrated FM radio transmitter and FM radio receiver 104 b to 104 h.
In this example, the FM radio systems such as the cellular phone 104 e, may transmit a telephone call for listening over the another FM radio device 110 such as an audio system of an automobile, via usage of the car's FM stereo system through FM signal 120 a using FM channel CH1. In another example, the smart wireless hand held device 104 f, may play media content such as songs to the another FM radio device 110 through broadcasting its media content through FM signal 120 e using a selected FM channel CH4 with least FM local channels interference from a local FM channel list. In an embodiment of the invention, the wire 166 f connecting the smart wireless hand held device 104 f to a listening device 108 may function as a high impedance external antenna for FM reception of FM signal 120 f while a 50 ohm matched antenna 166 e may be used for OOB transmission and/or reception of OOB signal 120 e.
In another example, a computer, such as the computer 104 g, may comprise an MP3 player or another digital music format player and may broadcast a FM signal 120 c through an unoccupied FM channel CH2 (deadband) to the another FM radio device 110 with a FM radio receiver. The music on the computer 104 g may then be listened to on the another FM radio device 110 with few, if any, other external FM transmission devices or connections. While a cellular phone 104 a, a smart wireless hand held device 104 b, and computing devices 104 c have been shown, a single chip 106 b that may combine an optional OOB and FM transceiver and/or OOB and FM radio receiver to be utilized in a plurality of FM radio systems 104 e to 104 h or in the another FM radio device 110 to transmit and/or receive FM signals 120 a to 120 d and OOB signal such as signal 120 e.
In this regard, the another FM radio device 110 with an FM radio receiver may comprise and/or may be optionally coupled to a listening device 108 using a wired connection 166 g or using an optional Out Of Band (OOB) signal 120 g. A device equipped with the OOB and FM transceivers, such as the single chip 106 b, may be integrated into each of the integrated FM radio transmitter and FM radio receivers 104 a to 104 d to enable broadcasting its “out of band” respective signal 120 e to the another FM radio device 110 outside the FM broadcasting band. The another FM radio device 110 may also comprise a visual display 110 a to display the channel being played in the text format, and a channel tuning system 110 b that enables a user 132 to intervene and select a preferred channel for FM reception through user input 188.
In this example, the smart wireless hand held device 104 b may use an OOB signal 120 e to send a list of ranked local FM channels to the another FM radio device 110, where the FM channel CH4 120 b may be the preferred channel with least neighboring channel interferences. The another FM radio device 110 may automatically tune to the preferred FM channel CH4 120 b and play the media content. In an embodiment of the invention, the FM radio device 110 may transmit through the in-band RDS/RDBS data to notify a user 132 of a channel CH4 switch through text display on a visual display 110 a, an alert tone or voice. Alternately, the FM radio device 110 may transmit through the in-band RDS/RDBS data to notify a user 132 to select a preferred channel from a list of alternate local FM channels by text message on a visual display 110 a, or by text to voice through a speaker or headset 108. The user 132 may either follow the recommendation of the local FM channel list to choose channel CH4, or the user 132 may judiciously tune the tuner 110 b to check the other alternate channels on the local FM channel list before making a decision. The process of dynamically generating a local FM channel list may be discussed in FIGS. 5A to 5F.
FIG. 3A is a diagram illustrating a dynamic scanning process of a FM radio system with an integrated FM radio transmitter and FM radio receiver in a FM frequency spectrum, in accordance with an embodiment of the invention. Referring to FIG. 3A, a FM radio system with an integrated FM radio transmitter and FM radio receiver such as the smart wireless hand held device 104 f may scan a FM spectrum to detect for an alternate FM channel such as channel CH4 302 d for local FM transmission.
Transmitted FM channel CH2 302 b may receive interferences from strong interfering neighboring channels CH1 302 a and CH3 302 c, or due to the channel CH2 302 b no longer available such as being used by a local FM broadcast station 102 a. A local oscillator (LO) in the smart wireless handheld device 104 f FM radio receiver may start scanning at LO frequency Fon. The LO may have an option to perform a full scan starting from CH1 302 a to generate and update a local FM channel list, or alternately the LO may start scanning from channel Ch5 302 e. The U.S. application Ser. No. 11/755,395 filed on May 30, 2007, discloses exemplary local FM channel tuning and detection, and is hereby incorporated herein by reference in its entirety.
FIG. 3B is a diagram illustrating a dynamic local FM channel tuning by a FM radio system with an integrated FM radio transmitter and FM radio receiver (FM Tx/Rx) based on a ranked local FM channel list or based on user intervention, in accordance with an embodiment of the invention. Referring to FIG. 3B, in this example a full scan may not be performed as in FIG. 3A, instead the FM radio receiver of the smart wireless handheld device 104 f may dynamically “jump” to an alternate suitable transmission channel CH4 302 d based on a ranked local FM channel list.
In another embodiment of the invention, the LO of the FM radio receiver in the smart wireless handheld device 104 g may arbitrarily “tune on the fly” to channel CH4 302 d directly without relying on prior information from the local FM channel list while the FM radio transmitter of the smart wireless handheld device 104 g may be tuned to channel CH4 302 d before or after the FM radio receiver reaches the same channel CH4 302 d to verify its transmission availability. In both instances, the LO may by-pass tuning to LO frequencies Fo1 304 a to Fo3 304 c and settle on Fo4 304 d without a rescanning. The channel ranking and the FM channel list may be updated dynamically based on the availability verification or non interfering detection by the FM radio receiver. Further description on the dynamically generating and ranking of the FM channel list may be illustrated in FIGS. 5A to 5F.
FIG. 4 is an exemplary diagram of a FM radio system 400 with an integrated FM radio transmitter and FM radio receiver (FM Tx/Rx) on a Chip (SOC) with an integrated Bluetooth (BT) or Out Of Band (OOB) transceiver 404 scanning local FM channels 486 b, in accordance with an embodiment of the invention. Referring to FIG. 4, there is shown a FM radio transmitter 486 a, a FM radio system 400, another FM radio device 460 a. The FM radio transmitter 466 a may comprise a radio station or a broadcasting device communicating FM channels 486 b to the FM radio system 400 and or to the another FM radio device 406 a. The FM radio system 400 may be an integrated Tx/Rx on a Chip (SOC) comprising an integrated Bluetooth (BT) or Out Of Band (OOB) transceiver 404.
In an embodiment of the invention, the FM radio system 400 may comprise a BT transceiver 404 and an FM transceiver 444 with an integrated clock generator 401. The BT transceiver 404 may comprise a BT/PLL LOGEN circuit 402, a BT receiver circuit BT RX 408, a BT transmit circuit BT TX 408, and suitable logic, circuitry, and/or code that may enable communicating with an external device 460 b with a baseband processor.
Accordingly, the BT PLL/LOGEN circuit 402 may comprise a PLL utilized to generate a signal utilized in the communication of BT data. One or more control signals may be provided by the BT transceiver 404 to the processor 440 and/or the memory 428. Similarly, one or more control signals 411 may be provided by the memory 428 and/or the processor 440 to the BT transceiver 404. In this regard, digital information may be exchanged between the BT transceiver 404 and the FM transceiver 444. For example, changes in operating frequency of the BT PLL/LOGEN circuit 402 may be communicated to the memory 428 through control signal 411 and/or the processor 440 such that the frequency control word 434 to a DDFS 416 may be altered to compensate for the frequency change. In another embodiment of the invention, the BT transceiver 404 may comprise additional circuitry to support out of band (OOB) signal communication, or optionally replacing the BT transceiver with an OOB transceiver.
The FM transceiver 444 may comprise suitable logic, circuitry, and/or code that may enable the transmission and/or reception of local FM channel 486 b. In this regard, the FM transceiver 444 may comprise a DDFS 416 clocked by the BT PLL/LOGEN circuit 402. Accordingly, the FM transceiver 444 may be enabled to utilize reference generated clock signal 414 of widely varying frequency. In this regard, the DDFS 416 may enable utilizing the output reference generated clock signal 414 of the BT PLL/LOGEN circuit 402 to generate signals utilized by the FM transceiver 444. In this manner, a reduction in power consumption and circuit size may be realized in the Integrated FM Tx/Rx system 400 by sharing a single BT PLL/LOGEN circuit 402 between the FM transceiver 444 and the BT transceiver 404.
In an exemplary operation of the FM radio system 400 with an integrated FM Tx/Rx, one or more signals such as signals 435 provided by the processor 440 may configure the FM transceiver 444 to either transmit or receive FM signals. To receive FM radio signals, the processor 440 may provide one or more signals 435 to power up the FM Rx block 432 and power down the FM Tx block 430. Additionally, the processor 440 may provide a frequency control word 434 to the DDFS 416 in order to generate an appropriate FM LO frequency (with IQ components 426 a and 426 b) based on the reference signal f _ref 414. In this regard, f _ref 414 may comprise an output of the BT PLL/LOGEN circuit 402.
For example, the BT PLL/LOGEN circuit 402 may operate at 900 MHz and the DDFS 416 may thus utilize the 900 MHz signal to generate, for example, signals in the “FM broadcast band”, or approximately 78 MHz to 100 MHz. The FM broadcast band may expand to cover wider range such as 60 to 130 MHz in some FM radio devices. In another embodiment of the invention, the FM transceiver 444 may be capable of receiving or transmitting higher frequencies such as the cellular to millimeter wave range using an exemplary super heterodyne radio architecture described in the U.S. application Ser. No. 11/755,395 filed on May 30, 2007 and is hereby incorporated herein by reference in its entirety.
The processor 440 may interface with the memory 428 in order to determine the appropriate state of any control signals and the appropriate value of the frequency control word 434 provided to the DDFS 416. To transmit FM signals the processor 440 may provide one or more signals 435 to power up the FM Tx block 430 and power down the FM Rx block 432. Additionally, the processor 440 may provide a frequency control word 434 to the DDFS 416 in order to generate an appropriate FM LO frequency (with IQ components 426 a and 426 b) based on the reference signal f _ref 414. Alternatively, the processor 440 may provide a series of control words 434 to the DDFS 416 in order to generate a FM signal. In this regard, the processor 440 may interface with the memory 428 in order to determine the appropriate state of any control signals 435 and the appropriate values of the control word 434 provided to the DDFS 416.
The memory 428 may comprise a FM channel list 452 a and RDS/RDBS data 452 b. The FM channel list 452 a may comprise one or more listings with dynamically updated local FM channels. The dynamically updated local FM channels 486 b may comprise detected occupied local FM channels (not available for local FM transmission) and/or unoccupied local FM channels (available for local FM transmission through FM Tx block 464). The RDS/RDBS 452 b may comprise information identifying such as alternate frequencies of programs being broadcasted by local FM station, channel spacing, the number of blocks and frames transmitted (for BER determination), the clock time, broadcasted program identification with known station ID, country code or country identity, regional links and Enhanced Other Networks (EON) etc. The RDS/RDBS data 452 b may be stored and retrieved from the memory 428 for dynamic tuning input and for validating occupied local FM channels being broadcasted.
In an embodiment of the invention, FM reception to detect local FM channels 486 b and FM channel transmission may be performed simultaneously by receiving control signals 435 from the processor 440 and coupling the FM Rx block 432 to an optional receive antenna 466 b and the FM Tx block 440 coupling to an optional antenna 466 c. Alternately, FM reception and FM transmission may be multiplexed by coupling the FM Rx block 432 and the FM Tx block 440 to an antenna 466 a through a bidirectional coupler. The antennae 466 a and 466 c may be used to transmit local FM channel list information 452 a to an external FM radio receiver 461 b/OOB receiver 461 c equipped FM radio device 460 a through out of band (OOB) signals 488 i such as using Bluetooth BT, Wireless Local Area Network (WLAN) or Wireless Wide Area Network (WWAN). Alternately, the local FM channel list information 452 a may be transmitted to the external FM radio receiver 461 b of FM radio device 460 a as an RDS/RDBS jump table using an in-band FM signal by closed loop tuning method.
In another embodiment of the invention, an optional GPS receiver 470 with antenna 466 d may be coupled to the processor 440 as optional input 491 to provide country information or radio location information to assist in local FM channel and channel spacing determination. In another embodiment of the invention, the external device 460 b may optionally be coupled to the FM radio system 400 with Integrated FM Tx/Rx to receive signal through a wire 466 d coupled to a plug and a jack connector 458. The wire 466 may be utilized as a reception antenna for the FM transceiver 444 while FM transmission may be performed through an internal antenna such as antenna 466 c. Other inputs such as input 496 may serve similar functions as input 188 of FIG. 2 to facilitate channel tuning determination.
In another embodiment of the invention, pauses 490 of a transmission stream 488 may be an indication of a valid local FM channel being transmitted for dynamically generating or updating a local FM channel list 452 a. A Pause frame may be used to halt the transmission of a sender for a specified period of time in a duplex communication mode where data may flow in both directions such as using FM Tx and FM Rx communication.
In another embodiment of the invention, a detection of a stereo pilot signal 492 (or pilot signal) may be used to identify a valid local FM channel 492 a for dynamically generating or updating a local FM channel list 452 a. The detection of a pilot signal 492 at a certain frequency may indicate a valid FM channel 492 a may be detected at the second harmonics of the pilot signal 492. For example, a 19 kHz pilot signal may indicate the presence of an FM channel audio signal at 38 kHz.
The another FM radio device 460 a may comprise a processor 461 a, a FM radio receiver 461 b and an OOB receiver 461 c. The FM radio receiver 461 b may receive transmitted channel data from the FM radio transmitter 486 a and/or the FM radio system 400, depending on the channel the FM receiver 461 b may be tuned to. In an embodiment of the invention, the OOB receiver 461 c may receive FM channel information such as the ranked local FM channel list 552D shown in FIG. 5C from the OOB transmitter 410 of the FM radio system 400.
FIG. 5A is an exemplary diagram illustrating dynamic detection of occupied or unoccupied local FM channels, in accordance with an embodiment of the invention. Referring to FIG. 5A, there is shown 12 exemplary local FM channels CH1 502 a to CH12 502 l in the local FM spectrum 500A after a full scan. There is shown seven detected occupied local FM channels CH1 502 a to CH3 502 c, CH5 502 e, CH8 502 h, CH9 502 i and CH11 502 k where each of the respective occupied local FM channels may have signal amplitude exceeding the RSSI detection threshold 506.
There is also shown FM channel CH6 502 f with a weak signal amplitude below the RSSI detection threshold 506 (near noise level), which may be a valid occupied channel after further verification with the RDS/RDBS data from the local FM station. In an embodiment of the invention, the FM channel CH6 502 f may be considered as an unoccupied channel available for local FM transmission.
There may be other spurious signals with weak signal amplitude in the local FM spectrum such as signals 504 a and 504 b that may not be regarded as usable local FM channels for transmission for reasons of irregular channel spacing, being too close to an interfering FM channel CH6 502 h, CH11 502 k or other reasons.
Alternately, there the FM channel CH1 502 a may be identified as a valid local FM channel being transmitted through a detection of an FM channel transmission pause 590 despite of its marginal RSSI level. Channel CH11 502 k may be identified as a valid local FM channel transmitted being a harmonic 592 a of a detected stereo pilot signal 592.
FIG. 5B is an exemplary diagram illustrating extraction of unoccupied local FM channels available for transmission, in accordance with an embodiment of the invention. Referring to FIG. 5B, there is shown a plurality of exemplary unoccupied local FM channels available for local FM transmission CH4 502 d, CH6 502 f, CH7 502 g, CH10 502 j and CH12 502 l extracted after a full scan of the local FM spectrum 500A shown in FIG. 5A.
The unoccupied local FM channels may be derived from detected occupied local FM channels. Vice versa, the occupied local FM channel may be inferred from the absence of a signal with significant amplitude such as above the RSSI detection level, in combination with at least one of the RDS/RDBS data information such as channel frequencies or channel spacing. Other exemplary inputs such as utilizing an optional GPS location information, channel frequency and channel spacing determination are disclosed in U.S. application Ser. No. 11/755,395, filed on May 30, 2007, which is hereby incorporated herein by reference, and may be used to generate a local FM channel list for suitable local FM channel transmission.
FIG. 5C illustrates an exemplary process of generating and ranking of FM channels list available for transmission, in accordance with an embodiment of the invention. Referring to FIG. 5C, there is shown one or more FM channel lists 552A to 552D may be derived from FIG. 5A or FIG. 5B. FM channel list 552A may comprise local FM channels CH1 502 a to CH12 502 l. In FIG. 5C, there is shown detected occupied local FM channels (circled channels) CH1 502 a to CH3 502 c, CH5 502 e, CH8 502 h, CH9 502 i and CH11 502 k, and unoccupied local FM channels CH4 502 d, CH6 502 f, CH7 502 g, CH10 502 j and CH12 502 l.
The FM Channel list 552B may be derived from the FM channel list 552A. The FM Channel list 552B may comprise of seven occupied local FM channels CH1 502 a to CH3 502 c, CH5 502 e, CH8 502 h, CH9 502 i and CH11 502 k. In an embodiment of the invention, the occupied local FM channels CH5 502 e, CH9 502 i, CH11 502 k, CH2 502 b, CH8 502 h, to CH3 502 c and CH1 502 a may be ranked according to the respective RSSI amplitude in the FM Channel list 552B. The FM channel CH5 502 e being the strongest RSSI level and channel CH1 502 a being the weakest RSSI level in the FM Channel list 552B.
The FM Channel list 552C may be derived from the FM channel list 552A. The FM Channel list 552C may comprise five exemplary unoccupied local FM channels CH4 502 d, CH6 502 f, CH7 502 g, CH10 502 j and CH12 502 l being available for local FM transmission as shown in FIG. 5B.
In an embodiment of the invention, the FM Channel list 552C may be ranked according to increasing neighboring channel interferences to generate a FM Channel list 552D. The FM Channel list 552D may illustrate an exemplary ranking order of CH7 502 g, CH6 502 f, CH4 502 d, CH12 502 l and CH10 502 j. The FM channel CH7 502 g may be ranked as the preferred transmitter channel 556A with the least neighboring channel interference. The FM channel CH10 502 j may be ranked as the least preferred transmitter channel with highest neighboring channel interference in the alternate transmitter channels 556B.
Referring to FIG. 5A and FM channel list 552D in FIG. 5C, there is shown FM channel CH7 502 g has two neighboring channels CH6 502 f and CH8 502 h. Neighboring channel CH6 502 f may have a noise floor signal amplitude (below RSSI detection threshold) and neighboring channel CH8 may have moderate to low signal amplitude. The FM channel CH6 has neighboring channels CH5 502 e and CH7 502 g. Although neighboring channel CH7 502 g may be at noise floor, neighboring FM channel CH5 502 e may be shown as the strongest interfering channel in the FM frequency spectrum 500A. Hence, the FM channel CH7 502 g may be ranked or preferred above channel CH6 502 f.
The channel CH4 502 d has neighboring channels CH3 502 c and channel CH5 502 e. The FM channel CH4 502 d may be inferior to channel CH6 502 f for reason that neighboring channel CH3 502 c is a valid occupied local FM channel above the noise floor, while channel CH6 502 f being neighboring to channel CH7 502 g at noise floor. Hence, the FM channel CH6 502 f may be ranked above channel CH4 502 d.
The channel CH12 502 l has only one strong interfering neighboring channels CH11 502 k. In an embodiment of the invention, the FM channel CH4 502 d may be inferior to the FM channel CH12 502 l for reason that the FM channel CH4 502 d has two neighboring channel while the FM channel CH12 502 l has one neighboring channel. In another embodiment of the invention, alternate FM channel CH6 502 f may have closer proximity to channel CH4 502 d (separated by two channel spacing) than to the FM channel CH12 502 l (separated by six channel spacing. Hence, the FM channel CH4 502 d may be ranked above the FM channel CH12 502 l.
The Channel CH10 502 j has two strong neighboring interfering channels CH9 502 i and CH11 502 l. The FM Channel CH12 502 l has only one strong interfering neighboring channels CH11 502 k. Hence, the FM channel CH12 502 l may be ranked above channel CH10 502 j.
The order of channel may vary depending on the ranking algorithm and other factors such as weighing factors, or spurious considerations may be included for ranking determination.
FIG. 5D is an exemplary diagram illustrating dynamic processing of alternate local FM channels for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention. Referring to FIG. 5D, the local FM channel list 552D may be communicated to another FM radio device 460 a with a FM and/or OOB receiver 461 c. The FM receiver 461 b of the another FM radio device 460 a may tune to the corresponding selected or preferred channel CH7 502 g with the least neighboring channel interferences. The FM receiver 461 b of the another FM radio device 460 a may upon receiving information such as a command from an in-Band FM signal 488 i or upon user intervention, jump to the next available preferred unoccupied local FM channel CH6 502 f on the ranked local FM channel list 552D. In accordance with an exemplary embodiment of the invention, an RDS/RDBS jump instruction or command may be created and utilized to facilitate a jump to the next available preferred unoccupied local FM channel CH6 502 f. Likewise, FM channel CH4 502 d, FM channel CH12 and FM channel CH10 502 j may follow according to the order of increasing neighboring FM channel interferences in the alternate FM channels 556D.
In another embodiment of the invention, the newly created exemplary RDS/RDBS jump instruction or command may be received as an in-band FM signal where the FM receiver 461 b of the another FM radio device 460 a may automatically tune by closed loop tuning method (to be discussed in FIG. 6B) to the next available preferred unoccupied local FM channel following the ranked local FM channel list 552D. An example of such implementation may be the channel frequency of an FM radio in a moving automobile may jump to the next available preferred unoccupied local FM channel automatically based on the newly created RDS/RDBS jump instruction or command.
FIG. 5E is an exemplary diagram illustrating a dynamic detection of occupied or unoccupied local FM channels when channel distribution changes, in accordance with an embodiment of the invention. FIG. 5E illustrates dynamic changes make take place within local FM channel spectrum 500B due to a channel distribution change of the FM radio system 400 with an integrated FM radio Tx/Rx receiver, or the local FM broadcasting channels distribution change at a different time instance. Referring to FIG. 5E, a scan by the FM radio system 400 with an integrated FM radio Tx/Rx receiver may detect that the local FM channel CH11 502 k may be switched to channel CH7 502 g. A user using the preferred FM channel CH7 502 g from the FM channel list 452 a may experience a strong interference at this channel since channel CH7 502 g may no longer be available for local FM transmission by the FM radio system 400 with an integrated FM Tx/Rx.
FIG. 5F illustrates an exemplary dynamic process of updating the local FM channel list for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention. Referring to FIG. 5F, there is shown an updated occupied local FM channel list 552E may be generated from a scan by the FM radio system 400 with an integrated FM radio Tx/Rx. The updated occupied local FM channel list 552E may comprise seven occupied local FM channels CH5 502 e, CH9 502 l, CH7 502 g, CH2 502 b, CH8 502 h, to FM CH3 502 c and FM CH1 502 a and they may be ranked according to the respective RSSI amplitude in the FM Channel list 552E.
The FM Channel list 552F may be derived from the FM channel list 552E. The FM Channel list 552C may comprise of five unoccupied local FM channels CH4 502 d, CH6 502 f, CH10 502 j, CH11 502 k and CH12 502 l that may be available for local FM transmission as shown in FIG. 5B.
The FM Channel list 552G may be updated and dynamically ranked according to neighboring channel interference. The FM Channel list 552G may illustrate an exemplary ranking order of CH12 502 l, CH11 502 k, CH10 502 j, CH4 502 d and CH6 502 f. The FM channel CH12 502 l may be ranked as the preferred FM transmitter channel 556C while the FM channel CH6 502 f may be ranked as the least preferred transmitter channel in the alternate channel list 556D. The ranking order in FM Channel list 552G may use similar neighboring interfering channel algorithm described in FIG. 5C.
The dynamic detection algorithm illustrated in FIGS. 5A to 5F may be enabled to determine which FM channels have the lowest noise floor, and accordingly select those channels as being suitable for transmission of FM data. The detection algorithm may be enabled to operate, for example, where there is a pause 490 in a transmitted FM stream 488. The detection algorithm may utilize simultaneous FM radio Tx and FM radio Rx or multiplexed FM radio Tx and FM radio Rx to determine those channels suitable for transmitting or broadcasting FM data shown in FIG. 4.
FIG. 5G is an exemplary diagram illustrating dynamic processing of updated alternate FM radio channels for transmission based on least neighboring channel interferences, in accordance with an embodiment of the invention. FIG. 5G is similar to FIG. 5D except that the transmission order of the preferred FM channel CH12 502 l and the alternate FM channels CH11 502 k, CH10 502 j, CH4 502 d and CH6 502 f may be rearranged in increasing neighboring channel interference reflected in the update in the local FM channel list 552G.
FIG. 5H illustrates an exemplary simultaneous scanning of a FM radio system 400 with an integrated FM Tx/Rx (as a source device) and another FM radio device 460 a with an FM radio receiver (as a sink device) to generate a substantially matched local FM channels list for available local FM transmission selection, in accordance with an embodiment of the invention. Referring to FIG. 5H, there is shown a substantially matched local FM channel list 552A, 552B, 552C or 552D may be generated from the FM frequency spectrum 500A. Simultaneous scanning or scanning in close succession may be performed by the FM radio system 400 with an integrated FM radio Tx/Rx 444 and by another FM radio device 460 a with an FM receiver. The FM radio system 400 may be a signal source as a source device transmitting FM channel information to a signal receptor, the another FM radio device 460 a as a sink device.
In this example, the another FM radio device 460 a with a FM radio receiver may be currently tuned to receive contents from the FM channel CH9 502 i during the simultaneous FM scan 402 b. The channel list 552A of the FM scan 402 b by the another FM radio device 460 a with a FM radio receiver may be used to compare a substantially matched FM channel list 552A FM scan 402 b sent through the FM or OOB signal 488 i by the FM radio system 400 with an integrated FM Tx/Rx.
FIG. 5I illustrates an exemplary tuning of another FM radio device with an FM radio receiver to a selected local FM channel in response to a detection of a sudden increase of RSSI level of a channel signal, in accordance with an embodiment of the invention. Referring to FIG. 5I, it is shown that a ranked local FM channel list 552D with a selected FM channel CH7 502 g for transmission based on least neighboring interferences may be generated or updated by the FM radio system 400 and communicated to the another FM radio device 460 a through an FM or OOB signal 488 i. Optionally, in another embodiment of the invention, a confirmation of such reception of the information, or a confirmation of a substantial matching of the FM channel list 552A or 552D from the FM scan 402 b may be communicated back from the another FM radio device 460 a to the FM radio system 400 through the FM or OOB signal 488 i.
The FM radio system 400 may start transmitting FM channel data at the preferred FM channel CH7 502 g, the another FM radio device 460 a with a FM radio receiver may detect a new signal shown by a sudden rise of RSSI level located at the selected channel CH7 502 g. Such new signal shown by a rise on RSSI level detection at channel Ch7 502 g may act as a command signal to automatically tune the another FM radio device 460 a to lock on to the selected FM channel CH7 502 g to continue to receive FM channel data. In an embodiment of the invention, the visual display 460 d may notify the user that the media content being played may be tuned to local FM channel Ch7 502 g. In an embodiment of the invention, an audio alert tone or a text to voice may be transmitted over the RDS/RDBS data from the FM radio system 400 to inform the user of the channel CH7 502 g switch. Alternately, the user may receive an audio alert tone or a text to voice command notification over the RDS/RDBS to initiate a user input 488 k to tune the another FM radio device 460 a to the selected FM channel CH7 502 g through a semi automatic tuning or through manual FM tuner 460 e.
In another embodiment of the invention, the another FM radio device 460 a may monitor a change in the Bit Error Ratio (BER) of the RDS/RDBS data transmitted indicated by the new signal located at the selected channel CH7 502 g (broadcasted by the FM radio system 400) may be introduced to the FM frequency spectrum 500C. The another FM radio device 460 a may automatically tune to the selected channel CH7 502 g using closed loop tuning method without user 132 intervention.
FIG. 6A is a flow chart that illustrates exemplary steps for processing results derived from detecting channels suitable for FM transmission, in accordance with an embodiment of the invention. Reference designations in FIG. 2, FIG. 4 and FIGS. 5A to 5F may be referenced to throughout the flow charts description at various steps in FIGS. 6A and 6B. Step 600 may represent an initial or a reset condition for a FM radio system 400 with an integrated FM Tx/Rx without prior knowledge of the location, channel frequencies and channel spacing information.
In step 602 the processor 440 of the FM radio system 400 with an integrated FM Tx/Rx may scan the FM spectrum 500A to generate or update one or more local FM channel lists 552A, 552 b, 552C or 552D shown in FIG. 5C. Channel list 552A may comprise local FM channels CH1 502 a to CH12 502 l in the local FM channel spectrum after a full scan. Channel list 552B may comprise ranked occupied local FM channels CH5 502 e, CH9 502 i, CH11 502 k, CH2 502 b, CH8 502 h, to CH3 502 c and CH1 502 a according to the respective RSSI amplitude. Channel list 552D may comprise ranked unoccupied FM channels CH7 502 g, CH6 502 f, CH4 502 d, CH12 502 l and CH10 502 j available for transmission. In step 604, the one or more local FM channel lists 552A, 552 b, 552C or 552D may be updated or may be used to derive a ranked local FM channel list 552D based on least neighboring channel interference analysis. For example, unoccupied local FM channels CH7 502 g, CH6 502 f, CH4 502 d, CH12 502 l and CH10 502 j may be updated or ranked in the FM Channel list 552D based on increasing order of neighboring channel interference.
In step 606, the FM radio system 400 may communicate the local FM channel list 552A, 552 b, 552C or 552D to another FM radio device 406 a with a FM receiver. In an embodiment of the invention, the FM radio system 400 may use an OOB transmitter 410 to communicate the updated local FM channel list to an OOB receiver 461 c of the another FM radio device 406 a. The OOB communication may be a Bluetooth, wireless local area network (WLAN), wireless wide area network (WWAN), cellular band or ZigBee signal. In another embodiment of the invention, both the FM radio system 400 and the another FM radio device 406 a may be equipped with an integrated OOB transceiver to enable bidirectional communication. Alternately, the FM radio system 400 may use an FM transmitter 440 to communicate the updated local FM channel list to an FM receiver 461 b of the another FM radio device 406 a.
In step 608, the another FM radio device 406 a may select a FM channel from the received ranked local FM channel list 552D from the FM radio system 400. In an embodiment of the invention, the preferred channel selected may be the least neighboring channel interference channel CH7 502 g. In another embodiment of the invention, any one of the alternate channels 556B from the ranked local FM channel list 552D may be selected arbitrarily.
In step 610, the FM radio receiver of the another FM radio device 406 a may tune to the selected FM channel CH7 502 g from the ranked local FM channel list 552D through open loop tuning, closed loop tuning or semi-closed loop tuning. In step 612, after the another FM radio device 406 a tunes to the selected FM channel CH7 502 g, the FM radio receiver of the FM radio system 400 and/or the FM radio receiver of the another FM radio device 406 a may from time to time continue to scan the FM spectrum 500A to check if the selected FM channel CH7 may have any high neighboring channel interferences due to dynamic channel distribution in the broadcast stations, or due to location changes of the FM radio system 400.
If a high neighboring channel interference may be detected in the existing transmitted channel CH7 502 g, in step 616, the FM radio system 400 may select the next available local FM channel such as CH6 502 f, CH4 502 d, CH12 502 l or CH10 502 j from the ranked local FM channel list. The FM radio system 400 may communicate through an FM or OOB signal 488 i the new channel selection to the another FM radio device 406 a to tune to the FM radio receiver of the another FM radio device 406 a to the newly selected channel in step 610. In step 612, if the FM radio receiver of the FM radio system 400 may not detect high neighboring channel interference in the existing transmitted channel CH7 502 g, the FM radio system 400 and/or the another FM radio device 406 a may return to step 602 to continue to scan, monitor and/or update the local FM channel list.
FIG. 6B is a flow chart that illustrates exemplary steps for open loop, closed loop or semi closed loop tuning of selected local FM channel, in accordance with an embodiment of the invention. Referring to FIG. 6B, there is shown the exemplary tuning steps using open loop, closed loop or semi closed loop tuning of the selected local FM channel CH7 502 g in step 610. In step 610 a, upon a local FM channel CH7 502 g selection by the another FM radio device 406 a, the another FM radio device 406 a and the FM radio system 400 may implement a user intervention check in step 610 a. If user intervention may be used, an open loop tuning may be implemented and continued in step 610 b.
In step 610 b, the FM radio receiver of the another FM radio device 406 a may receive update to the local FM channel list 552D by a re-scan, if necessary. The selected FM channel may be a channel with the least neighboring channel interference such as channel CH7 502 g. The selected channel information may be derived from a format of the RDS/RDBS data 452 b by the processor 440 and communicated to a user 132 through visual text display on the another FM radio device 406 a or the FM radio system 400. The selected channel information may be communicated to the user 132 in the form of text to voice audio means, or through a combination of both visual and audio notification.
In step 610 c, the user 132 may select a channel based on the updated local Fm channel list, in this example, the CH7 502 g based on the least neighboring channel interference recommended by local FM channel list 552D. Alternately, the user 132 may select another arbitrary channel from the alternate channels 556B in the ranked local FM channel list 552D. After the open loop tuning may be completed, the process may continue, in step 612, to check for the neighboring channel interference of the selected tuned channel by the user 132.
In instances where user intervention may not be used in step 610 a, a closed loop tuning process may be used starting step 610 d. The closed loop tuning process may be an automatic tuning without user intervention, or may be modified to allow some user intervention as a semi-closed loop tuning process. In step 610 d, the another FM radio device 406 a may receive update to the local FM channel list 552D by a re-scan, if necessary. In step 610 e, the FM radio receiver in the FM radio system 400 and the FM radio receiver of the FM radio system 400 6 a may scan simultaneously or in close succession the FM spectrum 500A. A local FM channel list 552 a, 552B, 552C or 552D may be generated by the FM radio system 400 and may be communicated to the another FM radio device 406 a through a signal that may not affect the FM transmission such as using the FM or OOB signal 488 i. In an alternate embodiment of the invention, the another FM radio device 406 a may communicate the local FM channel list 552 a, 552B, 552C or 552D to the FM radio system 400 for channel match comparison.
In step 610 f, the generated local FM channel list 552A, 552B, 552C or 552D may be compared for substantial match in the list. In instances where there may be no substantial match to the generated local FM channel list 552A, 552B, 552C or 552D, the process go to step 610 d to re-scan for an update to the FM local channel list 552A, 552B, 552C or 552D. In instances where there may be a substantial match in step 610 f, the tuning process may proceed to step 610 g for a closed loop tuning with no user intervention, or to step 610 c for semi-closed loop tuning with user intervention. In step 610 g, the FM radio system 400 may transmit FM channel data to the another FM radio device 406 a at the selected FM channel, CH7 502 g in this example. The FM radio receiver 461 b of the FM radio device 406 a may detect a new signal indicated by a sudden rise in RSSI level of signal or a change in the BER of the RDS/RDBS data at the selected channel CH7 502 g. In step 610 h, the another FM radio device 406 a may tune to the detected new signal channel CH7 502 g in response to a sudden rise of RSSI level or a change in the BER of the RDS/RDBS data at channel CH7 502 g and go to step 612 to check for channel CH7 502 g channel interference status after tuning.
In an alternate embodiment of the invention, the FM radio system 400 may programmed to jump to a next alternate channel on the local FM channel list 552D, or to an arbitrary channel on the list without following the order of ranking.
The steps of the processes in FIGS. 6A to 6B may be rearranged in a different order or substituted with similar or equivalent operation to accomplish the same result without departing from the scope and the spirit of the invention.
In accordance with various embodiments of the invention, the method for enabling communication comprising in a FM radio system 400 comprising an integrated FM radio transmitter 440 and FM radio receiver 432, dynamically generating a list 552A, 552 b, 552C or 552D with alternate local FM channels such as 502 a to 502 l, and communicating the generated list 552A, 552 b, 552C or 552D with alternate local FM channels 502 a to 502 l to another FM radio device 406 a. The FM channels 502 a to 502 l of the generated list 552A, 552 b, 552C or 552D may be dynamically updated and communicated to an FM radio receiver of another FM radio device 406 a.
In an embodiment of the invention, the FM radio transmitter 440 may communicate a selected FM channel CH7 502 g based on least neighboring channel interference from a ranked local FM channel list 552D to tune the FM radio receiver of the another FM radio device 406 a to the same selected FM channel CH7 502 g. In another embodiment of the invention, the FM radio system 400 may comprise an FM transmitter 440 or OOB transmitter 410 to communicate the local FM channel list 552A, 552 b, 552C or 552D with alternate local FM channels to an FM receiver 461 b or OOB receiver 461 c of the another FM radio device 406 a. The FM transmitter 440 and FM receiver 461 b or OOB transmitter 410 and OOB receiver 408 may communicate with one of FM, Bluetooth, WLAN and ZigBee signals 488 i.
Another embodiment of the invention may provide a machine-readable storage, having stored thereon, a computer program having at least one code section executable by a machine, thereby causing the machine to perform the steps as described herein for FM transmission in an integrated FM transmit receive (FM Tx/Rx) system.
Accordingly, the present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A method for enabling communication, the method comprising:

in a FM radio system comprising an integrated FM radio transmitter and FM radio receiver:

generating a list of local FM channels; and

communicating said generated list of local FM channels to another FM radio device.

2. The method according to claim 1, comprising dynamically updating said generated list of local FM channels.

3. The method according to claim 2, wherein said generated list of local FM channels comprises an alternate channel list.

4. The method according to claim 3, comprising communicating said alternate channel list to said another FM radio device using an in-band FM signal.

5. The method according to claim 4, wherein said FM radio receiver receives said communicated list of local FM channels, which is transmitted via said FM radio transmitter in said FM radio system.

6. The method according to claim 5, wherein said another FM radio device selects from said received list of local FM channels, an FM channel for receiving FM signals.

7. The method according to claim 6, wherein said FM radio receiver in said another FM radio device tunes to said selected FM channel for said receiving of said FM signals.

8. The method according to claim 1, wherein said FM radio system comprises an out-of-band transmitter.

9. The method according to claim 8, wherein said another FM radio device comprises a corresponding out-of-band receiver and a FM radio receiver.

10. The method according to claim 9, comprising transmitting said communicated list of local FM channels from said FM radio system via said out-of-band transmitter.

11. The method according to claim 10, wherein said another FM radio device receives via said corresponding out-of-band receiver, said communicated list of local FM channels.

12. The method according to claim 11, wherein said another FM radio device selects from said received list of local FM channels, an FM channel for receiving FM signals.

13. The method according to claim 12, wherein said FM radio receiver in said another FM radio device tunes to said selected FM channel for said receiving of said FM signals.

14. The method according to claim 9, where in said out-of-band transmitter and said out-band-receiver utilizes one of: FM, Bluetooth, WLAN, or ZigBee.

15. The method according to claim 1, comprising ranking said generated list of local FM channels based on least neighboring channel interference.

16. A system for enabling communication, the system comprising:

at least one processor for use in an FM radio system comprising an integrated FM radio transmitter and FM radio receiver;

said at least one processor generates a list of local FM channels; and

said at least one processor enables communication of said generated list of local FM channels to another FM radio device.

17. The system according to claim 16, wherein said at least one processor dynamically updates said generated list of local FM channels.

18. The system according to claim 17, wherein said generated list of local FM channels comprises an alternate channel list.

19. The system according to claim 18, wherein said at least one processor in said FM transmitter enables communication of said alternate channel list to said another FM radio device via an in-band FM signal.

20. The system according to claim 19, wherein said at least one processor in said FM radio receiver receives said communicated list of local FM channels, which is transmitted via said FM radio transmitter in said FM radio system.

21. The system according to claim 20, wherein said at least one processor in said another FM radio device selects from said received list of local FM channels, an FM channel for receiving FM signals.

22. The system according to claim 21, wherein said at least one processor in said another FM radio device enables said FM radio receiver to tune to said selected FM channel for said receiving of said FM signals.

23. The system according to claim 16, wherein said FM radio system comprises an out-of-band transmitter.

24. The system according to claim 23, wherein said another FM radio device comprises a corresponding out-of-band receiver, an FM radio receiver and at least one processor.

25. The system according to claim 24, wherein said at least one processor in said FM radio system enables transmission of said communicated list of local FM channels from said FM radio system via said out-of-band transmitter.

26. The system according to claim 25, wherein said at least one processor in said another FM radio device enables receiving via said corresponding out-of-band receiver, said communicated list of local FM channels.

27. The system according to claim 26, wherein said at least one processor in said another FM radio device selects from said received list of local FM channels, a FM channel for receiving FM signals.

28. The system according to claim 27, wherein said at least one processor in said another FM radio device enables said FM radio receiver in said another FM radio device to tune to said selected FM channel for said receiving of said FM signals.

29. The system according to claim 24, where in said out-of-band transmitter and said out-band-receiver utilizes one of: FM, Bluetooth, WLAN, or ZigBee.

30. The system according to claim 16, wherein said at least one processor ranking said generated list of local FM channels based on least neighboring channel interference.