Abstract:
Systems and methods for channel pairing a transmitter and a receiver are provided. In this regard, a representative method, among others, includes selecting a channel in a radio frequency (RF) band; transmitting a carrier and alert tone on the selected channel in the RF band; responsive to detecting the transmitted carrier and alert tone, demodulating the carrier and alert tone on the selected channel in the RF band and producing the demodulated alert tone; and responsive to detecting the produced alert tone, using the selected channel to establish a wireless link between the transmitter and receiver.

Description:
TECHNICAL FIELD 
     The present disclosure is generally related to transmitting and receiving devices and, more particularly, is related to systems and methods for channel pairing a transmitter and a receiver. 
     BACKGROUND 
     Multiple vendors presently offer compact FM transceivers that scan the commercial broadcast band and suggest unoccupied channels to use when channel pairing the compact transceiver to a local receiver. These approaches typically involve manually matching the transmitter and receiver channels. Manually matching the transmitter to the receiver channel can be a nuisance as well as a distraction to users, particularly when driving. 
     SUMMARY 
     Systems and methods for channel pairing a transmitter and a receiver are provided. In this regard, a representative system, among others, includes a transmitter and receiver. The transmitter selects a channel in a radio frequency (RF) band and transmits a carrier and alert tone on the selected channel in the RF band. The receiver receives and demodulates the carrier and alert tone. The receiver includes a speaker that produces the demodulated alert tone. The transmitter includes a microphone that is configured to detect the produced alert tone. Responsive to detecting the produced alert tone, the transmitter is configured to use the selected channel to establish a wireless link between the transmitter and receiver. 
     In this regard, a representative method, among others, includes selecting a channel in a radio frequency (RF) band; transmitting a carrier and alert tone on the selected channel in the RF band; responsive to detecting the transmitted carrier and alert tone, demodulating the carrier and alert tone on the selected channel in the RF band and producing the demodulated alert tone; and responsive to detecting the produced alert tone, using the selected channel to establish a wireless link between the transmitter and receiver. 
     Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an overview of a system that channel pairs a transmitter and receiver; 
         FIG. 2  is a high-level flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the system  100 , such as that shown in  FIG. 1 , having functionality of transmitter and receiver pairing sequence; 
         FIG. 3  is a flow diagram that illustrates another embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transmitter and receiver pairing sequence; 
         FIG. 4  is a flow diagram that illustrates yet another embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transmitter and receiver pairing sequence using minimum radio frequency (RF) transmission power; 
         FIG. 5  is a flow diagram that illustrates yet another embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transceiver and receiver pairing sequence using a low RSSI channel; and 
         FIG. 6  is a flow diagram that illustrates yet another embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transceiver and receiver pairing sequence with periodic autonomous re-sync. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary systems are first discussed with reference to the figures. Although these systems are described in detail, they are provided for purposes of illustration only and various modifications are feasible. After the exemplary systems are described, examples of flow diagrams of the systems are provided to explain the process for channel pairing a transmitter and a receiver. 
     Presently available short-range transmitters have to be manually tuned in order for their transmit channel to match the channel being received by a nearby receiver. The transmitter described in this disclosure could automatically move to the same channel as that which has been manually selected by the user of the nearby receiver. This would enable the compact short-range transmitter to take advantage of the audio output system of the receiver and may eliminate the need for a redundant and potentially lower performance audio output system on the compact transmitter itself. 
     In one possible use-case, if a car driver is listening to a recorded audio program via the wireless link between a short-range transmitter and the car&#39;s receiver and a new geographical region is entered in which the presently tuned receiver channel is occupied by a higher power commercial broadcast station, the transmitter described in this disclosure can automatically move to the unoccupied channel manually selected by the driver on the car&#39;s receiver. The driver does not take the extra step to manually match the transmitter channel to the car&#39;s receiver channel, facilitating to minimize driver distraction, as well as increase convenience. This use case would also apply to an on-going phone-call being transmitted to the car stereo from a transmitter integrated in the cell phone. 
     As another use-case example, if a car driver is listening to a commercial radio broadcast and using a global positioning system (GPS), turn-by-turn direction prompts from a global positioning system (GPS) or a personal navigation device (PND) device can be heard over the car&#39;s audio system regardless of which channel the driver is listening to at the time. If a car driver changes the receiver channel, the transmitter described in this disclosure can remain paired with the tuned receiver channel such that turn-by-turn directions continue to be heard by the driver on the presently selected channel. This use case would also apply to audio from an incoming phone call transmitted to the car stereo from a transmitter integrated in the cell phone. 
       FIG. 1  is an overview of a system  100  that channel pairs a transmitter  110  and receiver  125 . It should be noted that the transmitter  110  can be a transceiver as illustrated in  FIG. 1 . The transmitter  110  selects a channel in a radio frequency (RF) band and transmits a carrier and alert tone on the selected channel in the RF band using an antenna  105 . The receiver  125  receives the carrier and alert tone using antenna  120  and demodulates the carrier and alert tone. The receiver includes a speaker  130  that produces the demodulated alert tone. 
     The transmitter  110  includes an audio microphone  115  that is configured to detect the produced alert tone. Responsive to detecting the produced alert tone, the transmitter  110  is configured to use the selected channel to establish a wireless link between the transmitter  110  and receiver  125 . Detection of the alert tones can be done by a variety of means at the transmitter  110 . The audio picked up by the microphone  115  can be sent to a correlator (not shown) that matches the audio signal against the original alert tone being modulated and transmitted. A fast Fourier transform (FFT) module (not shown) could also be used to check for the presence of the alert tone or tones. 
     It should be noted that the transmitter  110  may be a stand-alone transmitter or a transmitter integrated into another portable device such as a cell phone, personal navigation device (PND), personal digital assistant (PDA) or MP3 player. In some cases, such as in a cell phone, the portable device may already have in integrated microphone built into it, in which case the transmitter  110  would have the capability to enable the existing microphone and to access its output. The process of channel pairing the transmitter  110  and receiver  125  is further described in relation to  FIGS. 2-6 . 
       FIG. 2  is a high-level flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the system  100 , such as that shown in  FIG. 1 , having the functionality of a transmitter and receiver pairing sequence. In steps  205  and  210 , the transmitter  125  ( FIG. 2 ) selects a channel in a radio frequency (RF) band and transmits a carrier and alert tone on the selected channel in the RF band. Responsive to the receiver  125  ( FIG. 1 ) detecting the carrier and alert tone on the selected channel, the receiver  125 , in step  215 , demodulates the carrier and alert tone on the selected channel in the RF band and produces the demodulated alert tone. Responsive to the transmitter  110  detecting the produced alert tone, the transmitter  110  uses the selected channel to establish a wireless link between the transmitter  110  and receiver  125 . 
       FIG. 3  is a flow diagram that illustrates another embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transmitter and receiver pairing sequence. In steps  305  and  310 , a user manually tunes a receiver  125  ( FIG. 1 ) to an unoccupied channel and manually presses a button on a transmitter  110  ( FIG. 1 ) to begin the transmitter to receiver pairing sequence. In step  315 , the transmitter  110  transmits a carrier and alert tone at a maximum transmission power on a first channel in the RF band. In step  320 , the receiver  125  receives and demodulates the transmitter carrier and alert tone on the first channel. The receiver  125  further produces the demodulated alert tone. 
     In step  325 , the transmitter  110  uses the microphone  115  ( FIG. 1 ) to detect the produced alert tone. In step  330 , the transmitter  110  determines whether the microphone  115  detects the produced alert tone from the receiver  125 . Responsive to the transmitter  110  not detecting the alert tone, the transmitter  110  increments to the next channel in the RF band and transmits the carrier and alert tone on the next incremented channel. The sequence is repeated at step  320  using the next incremented channel until the alert tone is detected. Responsive to the transmitter  110  detecting the alert tone, the transmitter  110  establishes a wireless link between the transmitter  110  and receiver  125  using the channel that the alert tone was on and detected. At step  340 , the transmitter  110  turns off the alert tone and begins transmission of, e.g., recorded audio, via the transmitter and receiver wireless link. 
     Alternatively or additionally, the transmitter  110  could transmit simultaneously on multiple channels with respective unique alert tones. The transmitter  110  can determine whether one of the unique alert tones is detected. Responsive to detecting one of the unique alert tones on one of the respective multiple channels, the transmitter  110  uses the one channel of the multiple channels associated with the detected unique alert tone to establish the wireless link between the transmitter  110  and receiver  125 . 
       FIG. 4  is a flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the system, such as that shown in  FIG. 1 , having the functionality of a transmitter and receiver sequence using minimum radio frequency (RF) transmission power. The functionality and operation of the system in  FIG. 4  is similar to the functionality and operation of the system in  FIG. 3  and so the system in  FIG. 4  includes steps  305 ,  310 ,  315 ,  320 ,  325 ,  330 ,  335 , and  340 . 
     The functionality and operation of the system in  FIG. 4  further include step  405  where the transmitter  110  can incrementally reduce the RF transmission power of the channel associated with the detected alert tone until the alert tone is no longer detected by the transmitter  110 . In step  410 , the transmitter  110  can incrementally increase the RF transmission power of the channel associated with the detected alert tone by a predetermined amount to provide a minimum acceptable signal-to-noise ratio wireless link. The functionality and operation of the system in  FIG. 4  can allow for a reduction in the RF transmission power level while a user can listen to the recorded audio on an empty channel. 
       FIG. 5  is a flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the system  100 , such as that shown in  FIG. 1 , having the functionality of a transceiver and receiver pairing sequence using a low RSSI channel. The functionality and operation of the system in  FIG. 5  is similar to the functionality and operation of the system in  FIG. 4  and so the system in  FIG. 5  includes steps  305 ,  310 ,  320 ,  325 ,  330 ,  340 ,  405 ,  410 , and  415 . 
     The functionality and operation of the system in  FIG. 5  further include step  505  where the transceiver  110  can be configured to receive the first channel in the RF band and configured to indicate that low received signal strength indication (RSSI) of the received channels are empty or unoccupied channels. In step  510 , the transceiver  110  can sequentially select channels in the RF band and determine whether each of the selected channels has low received signal strength indication (RSSI). In step  515 , the transceiver  110  records the low RSSI channels in an RSSI map of empty or unoccupied channels. In step  520 , the transceiver  110  determines whether the selected channel is at the end of the RF band. The transceiver  110 , in step  520 , repeats step  510  until the transceiver  110  determines whether the selected channel is at the end of the RF band. 
     If the selected channel is at the end of the RF band, the transceiver  110 , at step  525 , selects one of the low RSSI channels in the RSSI map of empty or unoccupied channels and transmits the selected low RSSI channel for channel pairing the transceiver  110  and receiver  125 . Alternatively or additionally, the alert tones could be spread across the bandwidth of the selected low RSSI channel such that the user does not hear the tones. Alternatively or additionally, the alert tones could be either high or low enough in frequency to be inaudible to the user, while still detectable to microphone  115  of the transceiver  110 . 
     Alternatively or additionally, the transceiver  110 , in step  505 , can be configured to receive the first channel in the RF band and record the received signal strength indication (RSSI) of the received channel. In step  510 , the transceiver  110  can sequentially select all channels in the RF band and determine an RSSI level of each of the selected channels. The transceiver  110 , in step  520 , repeats step  510  until the transceiver  110  determines whether the selected channel is at the end of the RF band. In step  515 , the transceiver  110  records the RSSI level of each of the selected channels in a channel map. In step  525 , the transceiver  110  determines a transmission power level that is a predetermined amount above the recorded RSSI level of each of the selected channels in the channel map and transmits the carrier and alert tone on any of the selected channels at the respective determined transmission power level. 
     One advantage, among others, is to allow the transceiver  110  and receiver  125  to synchronize regardless of whether the selected channel is occupied or empty because the determined transmission power level is high enough to over-ride any commercial broadcast station signal being monitored on the received channel at the time. For example, for a use-case in which turn-by-turn directions or unanticipated audio is to be heard over the commercial broadcast audio being received at the time, the channel map amplitude levels recorded by the transceiver  110  allows the transceiver  110  to transmit a large enough signal to block reception of the commercial broadcast signal and allows the alert tones to be detected and the unanticipated audio to be heard by the user via receiver  125 . 
     The alert tone detection loop includes similar steps as in  FIG. 4 , such as, steps  320 ,  325 , and  330 . However, the alert tone detection loop in  FIG. 5  further includes step  530  where the transceiver  110  increments to the next empty channel in the RSSI map of empty or unoccupied channels and transmits the carrier and alert tone on the incremented empty channel. The functionality and operation of the system in  FIG. 5  can allow for a reduction in the transmission power consumption while pairing the transceiver and receiver, limiting the transceiver&#39;s operations during channel pairing by checking the empty channels stored in the RSSI map of empty or unoccupied channels instead of checking all available channels in the RF band. 
       FIG. 6  is a flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the system  100 , such as that shown in  FIG. 1 , having the functionality of a transceiver and receiver pairing sequence with periodic autonomous re-sync. The functionality and operation of the system in  FIG. 6  is similar to the functionality and operation of the system in  FIG. 5  and so the system in  FIG. 6  includes steps  305 ,  310 ,  320 ,  325 ,  330 ,  340 ,  405 ,  410 ,  415 ,  505 ,  510 ,  515 ,  520 ,  525 , and  530 . 
     The functionality and operation of the system in  FIG. 6  include the transceiver  110  that can periodically determine whether audio is being transmitted and allow a re-sync when audio is not being transmitted. After the transceiver  110 , in step  610 , delays for a pre-determined time, the transceiver  110 , in step  615 , determines whether the audio is being transmitted. Responsive to determining that audio is being transmitted, the transceiver  110 , in step  620 , determines whether the user has disabled the periodic autonomous re-sync feature. 
     If the user has disabled the re-sync feature, the transceiver  110  stops the re-sync operation. If the user did not disable the re-sync feature, the sequence repeats at step  610 . Responsive to determining that audio is not being transmitted, the channel pairing sequence repeats at step  605  where the following steps starting at  605  enable the transceiver  110  to select one of the low RSSI channel in the RSSI map of empty channels and use the selected low RSSI channel for channel pairing the transceiver  110  and receiver  125 . The functionality and operation of the system in  FIG. 6  can allow the transceiver and receiver re-sync to periodically occur without user intervention to track the user&#39;s manual receiver channel changes. 
     It should be noted that any process descriptions or blocks in flowcharts should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. As would be understood by those of ordinary skill in the art of the software development, alternate embodiments are also included within the scope of the disclosure. In these alternate embodiments, functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved. 
     This description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments discussed, however, were chosen to illustrate the principles of the disclosure, and its practical application. The disclosure is thus intended to enable one of ordinary skill in the art to use the disclosure, in various embodiments and with various modifications, as are suited to the particular use contemplated. All such modifications and variation are within the scope of this disclosure, as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly and legally entitled.