JP2011502396A - Short range FM modulator / transmitter and system incorporating the same - Google Patents

Abstract

A short range radio transmitter device includes a radio signal modulator and transmitter, a receiver, and a controller coupled to the receiver. The controller and receiver operate to examine the frequency spectrum to select the radio signal modulator and transmitter transmission frequencies. A receiver system for use with a transmitter includes a data channel service capable receiver and a controller. The controller of the receiver system automatically tunes the data channel service capable receiver to the frequency identified in the data channel service component of the received signal.

Description

  The present invention relates to short range transmission and reception systems.

  Short-range FM modulator / transmitter devices for short-range (eg, home) broadcast content from portable satellite receivers, MP3 players and other home electronic devices to standard FM radio receivers for playback ing. In one example, an MP3 player is docked or otherwise connected to a low power short range FM modulator / transmitter. The FM modulator / transmitter is tuned to the selected broadcast frequency along with the user's home stereo. The content is then transmitted at the selected frequency and received and played by a home stereo (or other FM receiver).

"United States RBDS Standard Specification of the Radio Broadcast Data System (RBDS)", April 9, 1998

  Interference, noise, or licensed radio station broadcasts within the FM band may cause the received signal from the short range FM modulator / transmitter to be lost or lost. For example, when these systems are used in a mobile environment such as in a car, geographic changes or interference from systems in use in surrounding cars may affect the received signal. In a home environment, interference may be caused by the use of multiple systems or neighbors in the same home. In general, this interference is addressed by manually searching for free FM bands and then manually tuning both the modulator / transmitter and the radio receiver to the new frequency. This process can be frustrating and problematic, especially in mobile environments.

  The short-range radio transmitter device includes a radio signal modulator and transmitter, a receiver, and a controller coupled to the receiver. The controller and receiver operate to examine the frequency spectrum to select the radio signal modulator and transmitter transmission frequencies. A receiver system for use with a transmitter includes a data channel service capable receiver and a controller. The controller of the receiver system automatically tunes the data channel service capable receiver to the frequency identified in the data channel service component of the received signal.

  These and other features of the present invention will be better understood from the following detailed description of preferred embodiments of the invention taken together with the accompanying drawings.

  The accompanying drawings illustrate preferred embodiments of the present invention, as well as other information relevant to the present disclosure.

1 is a block diagram of a short range FM modulator / transmitter device according to one embodiment of the invention. FIG. 2 is a diagram of the FM modulator / transmitter of FIG. 1 showing in more detail the data channel service capable FM modulator / transmitter component of the modulator / transmitter device. FIG. FIG. 3 is a block diagram of an FM receiver unit. 4 is a diagram of the FM receiver unit of FIG. 3 showing in more detail the data channel service capable FM demodulator / receiver component of the receiver unit. FIG.

  A short range transmission / reception system is described that automatically identifies the allowable transmission frequencies for use by the system. In an embodiment, an FM receiver is incorporated into the FM transmitter device to scan the FM band and identify or identify the FM station with the least signal transmission interference for use by the system. In an embodiment, the FM transmitter is data that identifies the selected FM station, such as using a radio broadcast data system (RDBS) or radio data system (RDS) function embedded in the FM transmitter. Are transmitted to the receiver. Tuning to the recommended new FM station can be done manually or automatically, in which case the recommended transmission frequency is displayed to the user on the display or audibly communicated, if automatic Transmitters and / or receivers are automatically tuned to the new transmission frequency, and in an embodiment, when the jamming profiles from licensed broadcasters or other sources of jamming change with time and / or location, Can be tracked automatically.

  The RDS standard is defined by the European Broadcasting Federation to transmit small amounts of digital information using conventional FM radio broadcasting. The RDS system standardizes various types of information for transmission including time and station identification information. Similarly, the RDBS standard is the US version of RDS. The two standards are almost the same, but there are very few differences, mainly with a number assigned to each of the 31 music and other program formats that RBDS can identify. The RDBS standard is approved by the US National Radio Standards Committee and is incorporated herein by reference, “United States RBDS Standard Specification of the Radio Broadcast Data System (RBDS)”, April 9, 1998 (hereinafter “United States RBDS standard ").

  FIG. 1 is a block diagram of an FM transmitter device 100. In an embodiment, the transmitter device 100 includes an FM modulator / transmitter 110 capable of transmitting a small amount of digital data, such as having RBDS or RDS functionality. For example, the RBDS and RDS standards specify data transmission on a 57 kHz subcarrier to carry data at 1187.5 bits / second. In one embodiment, apparatus 100 utilizes an RDS / RBDS standard alternate frequency data field to convey an alternate transmission frequency, although any available data field may be utilized. FM modulator / transmitter 110 is known per se in the art, an example of which is shown in the diagram of FIG. 2 and is described in the US RBDS standard. The FM transmitter apparatus 100 also includes an antenna 160 for transmitting and receiving FM signals, a controller 120, a display 130, a simplified FM receiver 140, and a switch and tap module 150 coupled to the antenna 160.

  As shown in FIG. 2 and FIG. 4, the transmission / reception system uses RBDS-compatible transmitters and receivers, but can transmit any selected frequency data, such as in the sidebands of the transmission channel. Data transmission techniques can be used. In an embodiment, the data is transmitted as part of a high resolution wireless data stream or other data stream. An FM device capable of transmitting and receiving this data is referred to herein as “data channel service capable”.

  FM receiver 140 is of conventional design and is known per se in the art. FM receiver 140 is coupled to antenna 160 via a switch and tap module 150. The switch and tap module 150 includes a switch that can interrupt transmission of signals by the antenna 160 and / or by the FM modulator / transmitter 110 under the control of the controller 120, and FM signals received by the antenna 160. For supplying to the FM receiver 140. Of course, if the FM receiver 140 has its own antenna 160, no tap component is required. In embodiments, the transmitter controller 120 described herein may be a microprocessor programmed to operate according to the following description.

  The FM receiver 140 can be configured as a simple spectrum analyzer as used in some BLUETOOTH® compatible devices. The control device 120 starts scanning the FM band. Even FM receiver 140 or a simple RF detector sweeps the frequency at which the amount of RF energy at each radio station frequency is measured. The FM receiver will typically lock to the station and demodulate the signal, but this function is not required for the FM receiver 140 to detect jamming. The FM receiver 140 provides a power spectrum on the FM band to the controller 120. The controller 120 examines the power spectrum in the FM band to identify one or more frequencies with the least amount of interference, that is, the frequency with the lowest power level. Controller 120 then selects a frequency for use by FM modulator / transmitter 110, such as the frequency with the lowest power level.

  The controller 120 and the FM receiver 140 can continuously or periodically monitor the power spectrum in the FM band. If an increase in power above the selected power threshold is detected at and / or around the currently used transmission frequency by the FM modulator / transmitter 110, the controller 120 may cause an unacceptable level of noise or interference. And the FM band is checked for an acceptable alternative for the new transmission frequency, i.e., no frequency whose power level is below the selected power threshold.

  In an embodiment, the controller 120 temporarily stops transmission by the FM modulator / transmitter 110 during this test by switching off transmission by switching the switch and tap module 150. In this way, the FM band examined by FM receiver 140 and controller 120 of device 100 is not occupied or buried by its own transmission from FM modulator / transmitter 110. To take a snapshot of the power spectrum in the FM band, transmission from the FM modulator / transmitter 110 need only be stopped for a very short period of time, such as a period that is insensitive or hardly perceptible to the receiver.

  As described above, in one embodiment, controller 120 and FM receiver 140 perform their analysis periodically, such as every 30 seconds or other increments. Alternatively, the controller 120 and FM receiver 140 can continuously monitor the FM power spectrum.

  In an embodiment, the controller need not examine the entire FM spectrum. Rather, if noise or disturbance above a specified threshold is detected by the transmitter at the currently used transmission frequency, the controller will scan the FM band (eg, 87.5 MHz to 108.0 MHz). Initially, a first frequency below an acceptable power level threshold can be selected. Of course, use any acceptable algorithm to select the frequency with the smallest power footprint, select the frequency with a power footprint below the selected threshold, show an attractive power footprint A new transmission frequency can be selected, such as selection of adjacent frequencies.

  In one embodiment, when controller 120 selects a new transmission frequency, controller 120 displays the frequency on display 130 or uses a speaker (not shown) to audibly identify the frequency. Provide information. The controller can also provide an audible notification that a new frequency is available, thereby prompting the user to view the display 130.

  In an alternative embodiment, referring to FIG. 2, the controller 120 automatically changes the transmission frequency of the FM modulator / transmitter 110 by controlling the VHF / FM transmitter of the FM modulator / transmitter 110. In an embodiment, the controller 120 delays for a period of time before changing the transmission frequency of the FM modulator / transmitter 110, thereby using the transmission frequency already in use, eg, as shown in FIG. Data identifying the newly selected transmission frequency can be sent to the remote receiver device.

  The controller 120 provides data identifying the selected frequency to the FM modulator / transmitter 110. More specifically, the controller 120 provides the data to the wireless data message source component (FIG. 2) of the FM modulator / transmitter 110 and the FM transmission sent by the FM modulator / transmitter 110. Be included in the sideband. As will be described later, this frequency identification data is transmitted to the receiver device shown in FIGS. 3 and 4 for display or to automatically tune the receiver to the selected frequency.

  FIG. 3 is a block diagram of an FM receiver device 200 for use with the FM transmitter 100 described above in connection with FIGS. The FM receiver apparatus 200 includes a data channel service capable FM receiver / demodulator 210, such as a receiver having RBDS or RDS functionality. This receiver / demodulator unit 210 is known per se in the art, an example of which is shown in more detail in FIG. 4 and is described in the US RBDS standard. The receiver unit 200 also includes an FM receiver tuning controller 220 and a display 230, described in more detail below. In an embodiment, the FM receiver tuning controller 220 described herein may be a microprocessor programmed to operate according to the following description.

  Referring to FIG. 4, a data channel service capable FM receiver / demodulator unit 210 receives a FM signal received at antenna 240 and demodulates a standard VHF / FM receiver / demodulator that demodulates at a tuned frequency. Including. The remaining illustrated components of unit 210 provide a wireless data receiver / decoder that obtains data identifying the newly selected transmission frequency that is transmitted with the FM signal received at receiver unit 200. In operation, the VHF / FM receiver / demodulator of unit 210 is tuned to the preselected transmission frequency of transmitter 100 either manually or by FM receiver tuning controller 220. The VHF / FM receiver / demodulator receives the FM signal and demodulates the signal to provide a playback audio signal. Data from the FM signal identifying the newly selected transmission frequency is retrieved by the wireless data receiver / decoder component of unit 210 and provided to the FM receiver tuning controller 220 from the unit 210 data processor.

  In a manual embodiment, the FM receiver tuning controller 220 may display the newly selected frequency on the display 230 and provide an audible alert that a new frequency is available. The user then manually tunes the VHF / FM receiver / demodulator to the new frequency.

  In the automatic embodiment, the FM receiver tuning controller 220 automatically tunes the VHF / FM receiver demodulator of unit 210 to the frequency identified by the received frequency data.

  The invention described herein can be used for content over short distances (eg, 10 meters or less) to satellite receivers, MP3 players, cell phones, personal media players, media centers, personal computers and FM radio receivers. Is particularly suitable for use with a variety of household electronic devices, such as other household electronic devices that transmit.

  In one embodiment, the FM modulator / transmitter of FIG. 1 is provided in a first IC (integrated circuit) chip, and the controller 120 and FM receiver / spectrum analyzer 140 are provided in a second IC chip. It is done. This configuration allows the use of existing FM modulator / transmitter chips. Of course, if necessary, the controller 120, FM receiver 140 and FM modulator / transmitter 110 can be integrated on a single IC chip. In an embodiment, the FM receiver tuning controller 220 of the receiver unit can be integrated with the FM receiver / demodulator 210 or can be a separate IC.

  As described above, various combinations of transmitters and receivers can be utilized in a transmit / receive system. However, common to all systems is that the transmitter automatically identifies free transmission channel candidates for use by the system. Possible system embodiments include (A) a standard receiver used with the transmitter that selects and displays the newly selected frequency, and the user manually changes the station on the transmitter and receiver. (B) a data channel service capable transmitter and a data channel service capable receiver that displays the newly selected frequency, and the user manually changes the station to a new frequency on the receiver The transmitter is manually or automatically tuned, and / or (C) includes a data channel service capable transmitter and receiver, and the receiver and transmitter automatically track each other; is there.

  Although the invention has been described with reference to exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly to include other alternatives and embodiments of the invention that can be made by those skilled in the art without departing from the scope of equivalents of the invention. Don't be.

Claims (20)

A radio signal modulator and transmitter;
A receiver,
A short range radio transmitter device comprising: a control device coupled to the receiver;
A short-range radio transmitter apparatus in which the controller and receiver operate to examine a frequency spectrum to select transmission frequencies of the radio signal modulator and transmitter.   The short-range wireless transmitter device of claim 1, wherein the wireless signal modulator and transmitter are data channel service capable.   3. The short-range radio transmitter device according to claim 2, wherein the controller provides identification information of the selected transmission frequency to the radio signal modulator and transmitter for transmission to a remote receiver.   The control device automatically tunes the radio signal modulator and transmitter to the selected transmission frequency for transmission of radio signals after the identification information is transmitted to the remote receiver. 4. The short-range wireless transmitter device according to 3.   The short-range wireless transmitter device of claim 1, wherein the controller automatically tunes the wireless signal modulator and transmitter to the selected transmission frequency for transmission of wireless signals.   The short-range wireless transmitter device according to claim 1, further comprising a display, wherein the controller causes the display to display the selected transmission frequency.   The short-range radio transmitter device according to claim 1, wherein the controller interrupts transmission by the radio signal modulator and transmitter while the frequency spectrum is examined.   The short-range wireless transmitter device of claim 1, wherein the wireless signal modulator and transmitter are FM modulators and transmitters.   The short-range radio transmitter apparatus of claim 1, wherein when a disturbance is detected at a preselected transmission frequency, the controller and receiver are operative to examine the frequency spectrum.   The short-range wireless transmitter device of claim 1, wherein the controller and receiver are operative to examine the frequency spectrum at periodic intervals.   The short-range wireless transmitter device of claim 1, wherein the controller and receiver examine a power level for each frequency in the frequency spectrum. A data channel service capable receiver;
A receiver system comprising: a controller, wherein the controller automatically tunes the data channel service capable receiver to a frequency identified in a data channel service component of a received signal system.   The receiver of claim 12, wherein the data channel service capable receiver is an FM receiver. Radio signal modulator and transmitter for data channel service,
A receiver, and a transmitter device controller coupled to the receiver;
The controller and receiver operate to examine a frequency spectrum to select a transmission frequency of the radio signal modulator and transmitter, and the controller selects the selection for transmission to a remote receiver; A short-range radio transmitter device for providing said data channel service compliant radio signal modulator and transmitter with identification information of the transmitted frequency,
A transmission and reception system comprising a receiver device for data channel service.   15. The data channel service capable receiver device includes a receiver controller, and the receiver controller automatically tunes the data channel service capable receiver to the selected transmission frequency. The system described in.   15. The system of claim 14, wherein the data channel service capable receiver device includes a receiver controller and a display, the receiver controller displaying the selected transmission frequency on the display.   After the identification information is transmitted to the remote receiver, the transmitter device controller causes the data channel service capable radio signal modulator and transmitter to transmit the selected transmission frequency for radio signal transmission. 15. The system of claim 14, wherein the system is automatically tuned to.   15. The system of claim 14, wherein the transmitter device controller automatically tunes the data channel service capable radio signal modulator and transmitter to the selected transmission frequency for transmission of radio signals. .   15. The system of claim 14, wherein the transmitter device controller suspends transmission by the data channel service capable radio signal modulator and transmitter while the frequency spectrum is examined.   15. The system of claim 14, wherein the controller and receiver of the transmitter device checks a power level for each frequency in the frequency spectrum.

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