JP2007104095A - Diversity receiving circuit, apparatus, and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diversity receiving circuit with a comparatively simple configuration and smaller power consumption for receiving signals of a plurality of wireless communication systems and surely selecting an antenna with a high reception level. <P>SOLUTION: The diversity receiving circuit includes: a level comparison section 109 that compares a first reception level of a communication signal output from a first reception means 105A connected to any of a plurality of antennas with a second reception level of a communication signal output from a second reception means connected to any of the antennas not connected to the first reception means 105A to output a level comparison signal; a switching control means 110 that outputs a switching selection signal for selecting one by one antenna each connected to the first and second reception means 105A, 106A on the basis of a reception mode control signal and the level comparison signal for selecting a reception mode; and a switching selection means 102 that connects the two antennas to the first or second reception means 105A or 106A on the basis of the switching selection signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a diversity receiver in which reception circuits of different wireless communication systems are provided in the same band, and more particularly to a diversity reception circuit, a diversity reception device, and a diversity reception system that selectively switch antenna elements.

  In recent years, dual-mode reception systems of the same band have become widespread from the viewpoint of effective use of frequencies. For example, UMTS (Universal Mobile Telecommunication System) / GSM (Global System for Mobile Communications) of European mobile phones, digital television broadcasting, analog television broadcasting, and the like can be given.

  In particular, with regard to television broadcasting, terrestrial digital broadcasting started in December 2003 in Japan. On the other hand, the spread of analog terrestrial broadcasting is widespread, and simulcasting is required from the viewpoint of viewer protection when digitizing.

  Digital receivers that are integrated with receivers that are put on the market by December 2011, when the transition to digital broadcasting is completed, are desired to have analog broadcast reception functions. Many receivers will be put on the market in the future. Hereinafter, digital broadcasting and analog broadcasting will be described as examples.

  An orthogonal frequency division multiplexing (OFDM) technique is used for the transmission system of terrestrial digital broadcasting. OFDM is a type of multi-carrier modulation, and is distributed and digitally transmitted using a large number of orthogonal carriers for each symbol, so the symbol length is longer than that of a single carrier and the effects of delayed waves such as multipath. It is difficult to receive.

  FIG. 14 shows a conventional OFDM transmission symbol. 1401 represents an OFDM symbol, 1402 represents a guard interval period, and 1403 represents an effective symbol period. The OFDM symbol 1401 includes a valid symbol 1403 and a guard interval 1402, and the valid symbol period is a signal period substantially required for data transmission. The guard interval is a redundant signal period for reducing the influence of multipath. A part of the latter half of the effective symbol period is copied and added before the effective symbol for transmission.

  With this configuration, if the maximum delay amount of the delayed wave does not exceed the guard interval length, there is a phase change due to the delay, but since the periodicity of the synthesized wave is maintained, the frequency spectrum becomes the line spectrum and the code Interference does not occur. If the phase information can be corrected without breaking the orthogonality between the subcarriers, it can be completely demodulated.

  However, even if such a transmission method is used, the radio wave reception state deteriorates due to multipath fading, and stable reception is difficult. Diversity reception is an effective method for solving this problem.

  The selection diversity method that selects antennas so that good reception can be performed by switching multiple reception antennas, or the maximum ratio combining diversity method that combines the demodulated signals from multiple antennas in phase and with appropriate weights, More widely used in mobile radio receivers (for example, Non-Patent Document 1).

In addition, in a receiving apparatus having a single receiving system and having a plurality of antennas, a method of measuring the signal strength of each antenna and performing a switching operation when the signal intensity falls below a predetermined threshold is conventionally known. (For example, Non-Patent Document 2).
Seiichi Sampei, “From Digital Wireless Transmission Technology Basics to System Design”, Pearson Education, September 2002, Chapter 2, Chapter 4 Yoshihisa Okumura, Masaaki Shinji, “Basics of Mobile Communications”, edited by IEICE, October 1986, P176-178

  However, combining diversity methods such as maximum ratio combining require the same number of receiving systems as antennas and a combining circuit for combining the received OFDM signals, which complicates the configuration and consumes power. There is a situation that becomes larger.

  In addition, when diversity technology is installed in a small terminal such as a portable terminal, it is very difficult to configure an antenna with low correlation because it is not possible to place antennas physically apart from each other. Even if the switching operation is performed, the reception level at the other antenna is not necessarily high, and there is a situation that the reception performance is deteriorated conversely by performing the switching operation.

  The present invention has been made in view of the above circumstances, and receives a plurality of wireless communication system signals, and selects an antenna having a relatively simple configuration, lower power consumption, and a high reception level. It is an object of the present invention to provide a diversity receiving circuit, a diversity receiving device, a diversity receiving system, and a diversity receiving method.

  In order to achieve the above object, a first diversity receiving circuit of the present invention includes a plurality of antennas that receive communication signals of a plurality of wireless communication schemes, and a first that is connected to any one of the plurality of antennas. Of the communication signal output from the first receiver, a second receiver connected to any one of the plurality of antennas not connected to the first receiver, and the first receiver A level comparison unit that compares a reception level of 1 and a second reception level of a communication signal output from the second reception unit and outputs a level comparison signal indicating a comparison result; and communication in the plurality of wireless communication systems The first reception from the plurality of antennas based on a reception mode control signal for selecting a reception mode for receiving any one communication signal set in advance among the signals and the level comparison signal And a switching control unit that outputs a switching selection signal for selecting antennas to be connected to the second receiving unit one by one, and two of the plurality of antennas are connected to the first based on the switching selection signal A switching selection unit connected to the receiving unit or the second receiving unit.

  With this configuration, it is possible to receive a plurality of radio communication system signals, select an antenna having a relatively simple configuration, lower power consumption, and a high reception level.

  In the second diversity receiving circuit of the present invention, the plurality of wireless communication systems include a digital TV system and an analog TV system, and the first receiving unit receives the digital TV system broadcast signal. The second reception unit receives the analog television broadcast signal, and the reception channels of the first reception unit and the second reception unit have the same bandwidth.

  With this configuration, it is possible to receive a digital TV broadcast signal and an analog TV broadcast signal, and to select an antenna having a relatively simple configuration, lower power consumption, and a high reception level.

  Further, in the third diversity receiving circuit of the present invention, the digital television broadcasting signal has an OFDM signal, and the switching control unit is configured to switch the switching selection signal based on a guard interval signal included in the OFDM signal. Is configured to have a digital timing generation unit that generates a digital timing for outputting.

  With this configuration, it is possible to make it difficult for symbol synchronization to be lost during digital television reception.

  In the fourth diversity receiving circuit of the present invention, the switching control unit generates an analog timing for generating the analog timing for outputting the switching selection signal based on a vertical blanking period included in the analog television broadcasting signal. The timing generation unit is included.

  With this configuration, it is possible to make it difficult to cause unnecessary image quality degradation at the time of switching when the analog television receiver is used.

  Further, the fifth diversity receiving circuit of the present invention includes a power control timing generating unit that generates a power control timing for controlling a power based on the digital timing or the analog timing, and based on the power control timing. Power control for controlling power supply to the second receiver when the digital television system is selected as the reception mode, and power supply to the first receiver when the analog television system is selected as the reception mode Part.

  With this configuration, power consumption can be further reduced.

  In the sixth diversity receiver circuit of the present invention, when the switching control unit selects a digital television system as the reception mode, the reception level of the communication signal received by the antenna connected to the first receiver unit Includes a digital switching control signal that is output when the antenna connected to the second receiving unit is larger than a reception level of a communication signal received by the antenna, and the power control timing generation unit includes the digital switching control signal and The power supply control timing is generated based on the digital timing.

  With this configuration, power consumption during digital television reception can be further reduced.

  In the seventh diversity receiver circuit of the present invention, when the switching control unit selects an analog television system as the reception mode, the reception level of the communication signal received by the antenna connected to the second receiver unit Has an analog switching control signal that is output when the antenna connected to the first receiving unit is larger than the reception level of the communication signal received by the antenna, and the power control timing generation unit includes the analog switching control signal and The power supply control timing is generated based on the analog timing.

  With this configuration, it is possible to further reduce power consumption when receiving analog television.

  In the eighth diversity receiver circuit of the present invention, the switching selector connects one of the plurality of antennas to the first receiver or the second receiver based on the reception mode. The remaining antennas are selected one by one from the first antenna connecting unit and the remaining antennas that are not connected to the receiving unit among the plurality of antennas, and are sequentially switched to connect to the other receiving unit. And an antenna connection portion.

  With this configuration, the antenna having the highest reception level can be selected even in a severe fading environment with a plurality of antennas.

  The first diversity receiver of the present invention includes a plurality of antennas for receiving communication signals of a plurality of wireless communication schemes, a first receiving unit connected to any one of the plurality of antennas, A second receiving unit connected to any one of the plurality of antennas not connected to the first receiving unit; a first reception level of a communication signal output from the first receiving unit; and A level comparison unit that compares a second reception level of a communication signal output from the second reception unit and outputs a level comparison signal indicating a comparison result, and is set in advance among the communication signals of the plurality of wireless communication systems On the basis of a reception mode control signal for selecting a reception mode for receiving any one communication signal and the level comparison signal, the first reception unit and the second reception signal from the plurality of antennas. A switching control unit that outputs a switching selection signal for selecting antennas to be connected to each unit, and two of the plurality of antennas based on the switching selection signal, the first receiving unit or the second And a switching selection unit connected to the receiving unit.

  With this configuration, it is possible to receive a plurality of radio communication system signals, select an antenna having a relatively simple configuration, lower power consumption, and a high reception level.

  The first diversity receiving system of the present invention includes a plurality of antennas that receive communication signals of a plurality of wireless communication schemes, a first receiving unit that is connected to any one of the plurality of antennas, A second receiving unit connected to any one of the plurality of antennas not connected to the first receiving unit; a first reception level of a communication signal output from the first receiving unit; and A level comparison unit that compares a second reception level of a communication signal output from the second reception unit and outputs a level comparison signal indicating a comparison result, and is set in advance among the communication signals of the plurality of wireless communication systems Based on a reception mode control signal for selecting a reception mode for receiving any one communication signal and the level comparison signal, the first receiving unit and the second from the plurality of antennas A switching control unit that outputs a switching selection signal for selecting antennas to be connected to the receiving unit one by one, and two of the plurality of antennas are connected to the first receiving unit or the first based on the switching selection signal And a switching selection unit connected to the two receiving units.

  With this configuration, it is possible to receive a plurality of radio communication system signals, select an antenna having a relatively simple configuration, lower power consumption, and a high reception level.

  The present invention provides a diversity receiving circuit, a diversity receiving apparatus, and a diversity receiving system for receiving a plurality of radio communication system signals, selecting an antenna having a relatively simple configuration, lower power consumption, and a high reception level. Can be provided.

  In addition, diversity reception can be realized in a diversity reception apparatus or the like that includes one system each of digital and analog television receivers and includes a plurality of low-correlation antennas.

  In digital TV reception mode, connect one antenna to the digital TV receiver and the other antenna to the analog TV receiver, and compare the reception level of the digital TV receiver with the reception level of the analog TV receiver. Diversity reception can be performed by performing antenna switching control so as to select an antenna having a higher received electric field strength and using an analog television receiver as a level detector. In the analog television reception mode, it is possible to perform antenna switching control and receive diversity reception in the same manner.

  In the above diversity switching control, the digital television receiver uses the guard interval in the OFDM signal, and the analog television receiver uses the vertical blanking period, which is a section in which the video information in the video signal is not transmitted. Thus, symbol errors at the time of switching can be suppressed.

  Further, by limiting the level detection time and turning off the power supply of the level detection receiving system during periods other than the level detection time, low power consumption can be realized.

  Further, the above configuration realizes a diversity receiving circuit and the like relatively easily by adding a reception electric field level detector and a comparator using an existing analog television broadcast receiving module and digital broadcast receiving module. I can do it.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)

  FIG. 1 is a block diagram of a diversity receiver circuit 100 according to the first embodiment of the present invention. The diversity receiving circuit 100 includes a first antenna 101A, a second antenna 101B, a switching selection unit 102, input terminals 103A and 103B, output terminals 104A and 104B, a first receiving unit 105A, a second receiving unit 106A, 1 reception level detection means 107, second reception level detection means 108, level comparison means 109, switching control means 110, reception mode setting means 111, first demodulation output terminal 112, and second demodulation output terminal 113. .

  The first antenna 101A and the second antenna 101B are examples of a plurality of antennas. The switching selection unit 102 is an example of a switching selection unit. The first receiving unit 105A is an example of a first receiving unit. The second receiving unit 106A is an example of a second receiving unit. The level comparison unit 109 is an example of a level comparison unit. The switching control unit 110 is an example of a switching control unit.

  The diversity receiving circuit 100 in the present embodiment having such a configuration operates as follows. For the sake of explanation, in the present embodiment, the first wireless communication system is represented by ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television broadcast, and the second wireless communication system is represented by NTSC (National Television Standards Committee) analog television broadcast. The first receiving means 105A in 1 will be described as a digital television broadcast receiving means, and the second receiving means 106A will be described as an analog television broadcast receiving means.

  The reception signals received by the first antenna 101A and the second antenna 101B are input to the input terminal 103A and the input terminal 103B of the switching selection unit 102, respectively. The switching selection unit 102 performs switching so that the received signal is output to one of the output terminals 104A and 104B in accordance with the switching selection control signal output from the switching control unit 110 and for switching the antenna.

  The reception signal output from the output terminal 104A of the switching selection means 102 is input to the first reception means 105A, and the reception signal output from the output terminal 104B of the switching selection means 102 is input to the second reception means 106A. .

Here, the switching state by the switching selection means 102 will be described with reference to FIGS. 2A and 2B.
FIG. 2A is a diagram illustrating a first switching state of the switching selection unit 102 according to the first embodiment of the present invention. FIG. 2A shows a case where the switching selection means 102 receives the first received signal received by the first antenna 101A from the input terminal 103A and outputs it to the output terminal 104A. On the other hand, the switching selection means 102 receives the second received signal received by the second antenna 101B from the input terminal 103B and outputs it to the output terminal 104B.

  FIG. 2B is a diagram illustrating a second switching state of the switching selection unit 102 according to the first embodiment of the present invention. FIG. 2B shows a case where the switching selection means 102 receives the first received signal received by the first antenna 101A from the input terminal 103A and outputs it to the output terminal 104B. At this time, on the other hand, the switching selection means 102 inputs the second received signal received by the second antenna 101B from the input terminal 103B and outputs it to the output terminal 104A. The switching control unit 110 switches the first antenna 101A and the second antenna 101B to the first receiving unit 105A and the second receiving unit 106A by setting the first switching state or the second switching state in FIG. Connect to one of the following. Further, the switching selection means is described in, for example, “Transistor Technology” December 2004 issue P124 issued by CQ Publisher.

  Diversity receiving circuit 100 operates in an analog broadcast signal reception mode for receiving analog television broadcasts and a digital broadcast signal reception mode for receiving digital television broadcasts. These modes and reception channels are set by reception mode setting means 111. Set. At that time, at the time of setting the analog broadcast signal reception mode, the reception mode setting unit 111 sets the first reception unit 105A to be the same channel as the second reception unit 106A. At the time of setting the digital broadcast signal reception mode, the reception mode setting unit 111 performs setting so that the second reception unit 106A has the same channel as the first reception unit 105A. The reception mode control unit 111 outputs a reception mode setting signal, which is a signal for setting the analog broadcast signal reception mode or the digital broadcast signal reception mode, to the switching control unit 110.

  The first receiving means 105A performs amplification, frequency conversion, band limitation and digital demodulation on the received signal obtained from the output terminal 104A, and outputs it as a demodulated signal from the first demodulation output terminal 112. On the other hand, the second receiving means 106A performs amplification, frequency conversion, band limitation, and analog demodulation on the received signal obtained from the output terminal 104B, and outputs it as a demodulated signal from the second demodulation output terminal 113.

  In order to detect the reception level of the reception signal obtained from the first antenna 101A and the second antenna 101B, the first reception level detection unit 107 is connected to the first reception unit 105A, and the second reception is performed. The second reception level detection means 108 is connected to the means 106A.

Here, FIG. 3 is a schematic diagram of the first receiving means 105A in the first embodiment of the present invention.
The television broadcast signal input from the output terminal 104 </ b> A of the switching selection unit 102 is subjected to out-of-band interference wave removal by the band-pass filter 301, and is amplified by an RF (Radio Frequency) amplifier 302. The mixer 303 mixes the reception signal amplified by the RF amplifier 302 and the sine wave signal oscillated by the local oscillator 304, and performs frequency conversion to a certain intermediate frequency signal. The intermediate frequency signal is band-limited to a channel bandwidth by a band pass filter 305, and sent to an AGC (Auto Gain Control) 306 and a first reception level detection means 107.

  The first reception level detection means 107 is a block that outputs a first reception level signal as an electric field strength signal from the input AC signal, and measures the power of the reception signal band-limited to the channel bandwidth. In the present embodiment, the band of the digital or analog signal is 6 MHz, and the first reception level detection means 107 detects the signal level for both the analog signal and the digital signal by measuring the in-band power. It is possible to

  The AGC 306 is an amplifying unit whose gain is adjusted by the baseband unit 308 so that the band-limited intermediate frequency signal is input to an A / D (Analog to Digital) converter 307 with constant power. The A / D converter 307 converts the gain-adjusted signal (analog intermediate frequency signal) into a digital signal. The baseband unit 308 performs demodulation processing on the obtained digital signal and outputs the demodulated signal to the first demodulation output terminal 112.

FIG. 4 is a schematic diagram of the second receiving means 106A in the first embodiment of the present invention.
The television broadcast signal input from the output terminal 104B of the switching selection unit 102 is subjected to out-of-band interference wave removal by the bandpass filter 401 and amplified by the RF amplifier 402.
The mixer 403 mixes the reception signal amplified by the RF amplifier 402 and the sine wave signal oscillated by the local oscillator 404, and performs frequency conversion to a certain intermediate frequency signal. The intermediate frequency signal is band-limited by the band pass filter 405 to the channel bandwidth, and is input to the analog detection unit 406 and the second reception level detection means 108. The analog detection unit 406 demodulates the input intermediate frequency signal and outputs the demodulated signal to the second demodulation output terminal 113.

  The second reception level detection means 108 is a block that outputs a second reception level signal as an electric field strength signal from the input AC signal, and measures the power of the reception signal band-limited to the channel bandwidth. By measuring the signal power limited to the channel band by the band pass filter 405, the level of the analog signal or the digital signal can be detected by the second reception level detecting means 108.

  The level comparison unit 109 compares the level of the first reception level signal output from the first reception level detection unit 107 and the second reception level signal output from the second reception level detection unit 108. The comparison result is output to the switching control means 110 as a level comparison signal.

  For example, when the output signal level of the second reception level detection unit 108 is larger than that of the first reception level detection unit 107, the level comparison unit 109 sends a logic signal “1” to the second reception level detection unit 108. In comparison, when the output signal level of the first reception level detection means 107 is large, it can be realized by using a comparator circuit that outputs a logic signal “0”.

  The switching control unit 110 controls the switching selection unit 102 based on the input level comparison signal and the reception mode setting signal. The control method is as follows.

  When the reception mode set by the reception mode setting unit 111 is the digital broadcast signal reception mode, the power in the reception channel received by the first reception unit 105A is supplied to the level comparison unit 109 via the first reception level detection unit 107. The power in the reception channel received by the second reception means 106A set to the same channel as the first reception means 105A is input to the level comparison means 109 via the second reception level detection means 108. The

  When the output level of the first reception level detection means 107 is higher than the output level of the second reception level detection means 108, the switching control means 110 maintains the state of the switching selection means 102, and conversely, When the output level of the reception level detection means 107 is smaller than the output level of the second reception level detection means 108, the switching control means 110 performs control so as to invert the state of the switching selection means 102, and always performs the first operation. The switching selection means 102 is controlled so as to select an antenna having a higher electric field strength received by the receiving means 105A.

  Similarly, when the reception mode set by the reception mode setting unit 111 is the analog broadcast signal reception mode, the power in the reception channel received by the second reception unit 106A is compared with the level via the second reception level detection unit 108. The power in the reception channel that is input to the means 109 and received by the first receiving means 105A set to the same channel as the second receiving means 106A is supplied to the level comparing means 109 via the first reception level detecting means 107. Entered.

If the output level of the second reception level detection means 108 is higher than the output level of the first reception level detection means 107, the switching control means 110 maintains the state of the switching selection means 102, and conversely When the output level of the reception level detection means 108 is smaller than the output level of the first reception level detection means 107, the switching control means 110 performs control to invert the state of the switching means 102, and always performs the second reception. The switching selection means 102 is controlled so that the antenna received at the means 105A has a higher electric field strength.

Here, a control method of the switching control means 110 will be described.
FIG. 5 is a diagram showing a control method of the switching control means 110 in the first embodiment of the present invention.
In FIG. 5, “D” in the column “comparison output means” represents the output level of the first reception level detection means 107, and “A” in the column “comparison output means” represents the second reception level. The output level of the detection means 108 is shown.

  “Switching control” represents two switching states of the switching control unit 102, and “forward rotation” in the column of “switching control” is to maintain the current state of the switching control unit 102; “Inversion” in the “switch control” column means to invert the current state of the switch control means 102.

Next, a specific input signal and movement of each control signal will be described.
FIG. 6 is a diagram showing input signals and control signals in the digital broadcast signal reception mode in the first embodiment of the present invention.

  In FIG. 6, a received signal 601 (dotted line) by the first antenna 101A represents a time change of a signal input from the first antenna 101A, and a received signal 602 (solid line) by the second antenna 101B is The time change of the signal input from the 2nd antenna 101B is represented.

  Further, the switching control 603 indicates a time change of the level comparison signal output by the level comparison unit 109 and the switching selection control signal output by the switching control unit 110. At times “t1” and “t2”, the magnitude relationship between the received signal 601 from the first antenna 101A and the received signal 602 from the second antenna 101B is reversed. At this timing, the switching control 603 outputs a switching control selection signal, and each received signal has an output change 604 (solid line) of the first reception level detection means 107 and an output change 605 (second reception level detection means 108). Change with time as shown by dotted line.

  By performing the operation as described above, it is possible to select an antenna having a higher reception level and obtain a diversity effect.

  In addition, although the comparator was mentioned as an example as the level comparison detection means 109, it is possible to improve the noise resistance at the time of switching by using a hysteresis comparator. Further, the first reception level detection means 107 and the second reception level detection means 108 perform level comparison, and control is performed so as to select an antenna having a higher level. Alternatively, control may be performed so that the antenna switching operation is not performed below a certain threshold.

  The switching control means 102 is arranged between the first and second antennas 101A and 101B and the first and second receiving means 105A and 106A. In order to reduce the noise figure of the system, the switching control means 102 is shown in FIG. It may be connected to the subsequent stage of the RF amplifier 302 in FIG. Although the setting method of the reception mode setting unit 111 is not mentioned, for example, manual operation by an operator or the like, or automatic operation by a CPU (Central Processing Unit) or the like may be used.

It is also possible to prioritize selection of antennas with higher priority as an initial state at an arbitrary timing such as when the power is turned on by giving priority to selection between the first antenna 101A and the second antenna 101B. It is.

  In addition, when the selectivity of one of the first antenna 101A and the second antenna 101B is very high, power consumption can be suppressed by stopping detection of the reception level of the other antenna for a certain period of time. Is also possible.

  In this embodiment, the reception bandwidth has been described as 6 MHz. However, the bandwidth is not necessarily 6 MHz, and the first reception unit 105 </ b> A and the second reception unit 106 </ b> A can perform comparison of electric field levels. If so, it does not limit the bandwidth.

  In the present embodiment, the ISDB-T digital television broadcast is used as the first wireless communication system and the NTSC analog television broadcast is used as the second wireless communication system. If there is, the same effect can be obtained by equalizing the band power measured in the first reception level detection means 107 and the second reception level detection means 108.

  According to the diversity receiving circuit 100 in the first embodiment of the present invention as described above, a plurality of antennas that receive a plurality of communication signals of a plurality of wireless communication schemes are connected to any one of the plurality of antennas. From the first receiving unit 105A, the second receiving unit 106A connected to any one of the plurality of antennas that are not connected to the first receiving unit 105A, and the first receiving unit 105A A level comparison unit 109 that compares the first reception level of the output communication signal and the second reception level of the communication signal output from the second reception unit 106A, and outputs a level comparison signal indicating the comparison result; Reception mode control signal and level ratio for selecting a reception mode for receiving any one communication signal set in advance among communication signals of a plurality of wireless communication systems Switching control means 110 for outputting a switching selection signal for selecting antennas connected to the first receiving means 105A and the second receiving means 106A one by one from a plurality of antennas based on the signals, and based on the switching selection signals , Receiving a plurality of wireless communication system signals by having a switching selection means 102 for connecting two of the plurality of antennas to the first receiving means 105A or the second receiving means 106A, An antenna having a relatively simple configuration, lower power consumption, and a high reception level can be reliably selected.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
FIG. 7 is a block diagram of a diversity receiving circuit 700 according to the second embodiment of the present invention. In FIG. 7, the same reference numerals and functions as those used in the diversity receiving circuit 100 according to the first embodiment of the present invention have the same names and the same functions, and the description thereof will be omitted.

  The diversity receiving circuit 700 includes a video demodulation output terminal 114 and an audio demodulation output terminal 115 in addition to the diversity receiving circuit 100 according to the first embodiment of the present invention. The first receiving means 105A of the diversity receiving circuit 700, Instead of the second receiving means 106A, a first receiving means 105B and a second receiving means 106B are provided. The first receiving means 105B includes a first tuner unit 116 and an OFDM demodulating unit 117. The OFDM demodulator 117 includes an AD converter 118, an FFT (Fast Fourier Transform) decoder 119, a demodulator / decoder 120, and an FFT window setting unit 121. The second receiving unit 106B includes a second tuner unit 122, a band limiting unit 123, and a demodulation unit 124. The demodulator 124 includes a video receiver 125, a timing generator 126, and an audio receiver 127. Furthermore, the switching control unit 110 includes a reception timing switching unit 128 and a switching control unit 129.

  The first receiving means 105B is an example of a first receiving unit. The second receiving means 106B is an example of a second receiving unit. The FFT window setting unit 121 is an example of a digital timing generation unit. The timing generator 126 is an example of an analog timing generator.

  The diversity receiving circuit 700 is different from the diversity receiving circuit 100 in that the timing of the switching control by the switching control unit 110 is not an arbitrary timing as shown in the first embodiment, but the first receiving unit 105B or the second receiving unit 105B. The switching control is performed according to the timing obtained by the receiving means 106B.

Hereinafter, the operation of the diversity receiving circuit 700 will be described. First, the operation at the time of digital broadcast reception will be described.
In the first receiving means 105B, the first tuner section 116 amplifies, frequency-converts, band-limits, and quadrature-demodulates the transmission signal output from the output terminal 104A of the switching control means 102 as an input signal, and outputs an intermediate frequency signal. To the OFDM demodulator 117. In the OFDM demodulator 117, the AD converter 118 converts the intermediate frequency signal obtained from the first tuner unit 116 into a digital signal and outputs it as an OFDM signal to the FFT decoder 119 and the FFT window setting unit. The FFT window setting unit 121 sets an FFT window based on the OFDM signal converted by the AD conversion unit 118.

  The FFT decoding unit 119 extracts a signal included in the FFT window period set by the FFT window setting unit 121 from the OFDM signal output from the AD conversion unit 118, performs an FFT process, and converts the signal into a signal on the frequency axis. Convert. Here, the setting of the FFT window period is disclosed in Japanese Patent Application Laid-Open Nos. 2000-022657 and 2001-308762. The demodulation / decoding unit 120 reproduces data by demodulating and further decoding the signal output from the FFT decoding unit 119, and outputs the data from the first demodulation output terminal 112.

  On the other hand, in the second receiving means 106B, the second tuner section 122 amplifies and frequency-converts the transmission signal input from the output terminal 104B of the switching control means 102 as an input signal, and performs a band limiting section as an intermediate frequency signal. 123. The band limiting unit 123 band-limits the input intermediate frequency signal to the reception channel band and inputs it to the demodulation unit 124. When receiving the digital broadcast signal, the signal input to the demodulator 124 is input to the video receiver 125 that receives the video signal and the audio receiver 127 that receives the audio signal via the video receiver 125. The video signal input to the video receiver 125 is output to the video demodulation output terminal 114. The audio signal input to the audio receiving unit 127 is output to the audio demodulation output terminal 115.

  Next, level comparison will be described. The first reception level detection means 107 detects 6 MHz power in the reception band from the intermediate frequency signal of the first tuner unit 116. The second reception level detection means 108 detects the power of 6 MHz in the reception band from the intermediate frequency signal output from the band limiting unit 123. The level comparison means 109 compares the power levels detected by the first and second reception level detection means 107 and 108.

  Next, the operation of the switching control unit 110 will be described. The operation of the switching control means 110 differs in the control method between when the timing is obtained from the digital broadcast wave and when the timing is obtained from the analog broadcast wave as the switching timing of the switching selection means 102.

  When the timing is obtained from the digital broadcast wave, the reception timing switching unit 128 selects the digital timing output from the FFT window setting unit 121 based on the reception mode setting signal output from the reception mode setting unit 111. The digital timing is a signal in a guard interval period that is output at approximately a symbol long period. This digital timing and level comparison signal from the level comparison means 109 is sent from the reception timing switching means 128 to the switching control section 129. The result of the level comparison at the digital timing is sent from the switching control unit 129 to the switching selection means 102. The switching selection means 102 selects an antenna with a higher signal level and improves reception quality. The switching control unit 129 can be easily realized by, for example, a D flip-flop.

Next, the operation when receiving an analog broadcast will be described.
In the second receiving unit 106B, the second tuner unit 122 amplifies and frequency-converts the transmission signal output from the output terminal 104B of the switching selection unit 102 as an input signal, and outputs it to the band limiting unit 123 as an intermediate frequency signal. To do. The band limiting unit 123 band-limits the intermediate frequency signal input for removing unwanted interference waves to the 6 MHz band and inputs the intermediate frequency signal to the demodulation unit 124.

  The video receiving unit 125 extracts a video signal from the band-limited intermediate frequency signal and outputs the video signal to the video demodulation output terminal 114. The audio receiving unit 127 extracts an audio signal from the band-limited intermediate frequency signal and outputs the audio signal to the audio demodulation output terminal 115. The timing generator 126 detects a vertical blanking period from the video receiver 125 and outputs a signal representing the vertical blanking period. Here, the vertical blanking period is disclosed in, for example, Japanese Patent Application Laid-Open No. 06-085720.

  On the other hand, for the analog broadcast signal received by the first receiving unit 105B, the first tuner unit 116 amplifies, frequency converts, and transmits the transmission signal output from the output terminal 104A of the switching selection unit 102 as an input signal. The band is limited to the 6 MHz band, and is output to the OFDM demodulator 117 and the first reception level detection means 107 as an intermediate frequency signal.

  When comparing the levels of the analog broadcast signals input to the second receiving means 106B and the first receiving means 105B, the first and second reception level detecting means 107 and 108 are connected to the first and second tuner sections 116, respectively. And 122 or the band limiter 123 detects the 6 MHz power in the reception band, and the level comparison means 109 compares the power level. The switching control unit 110 sends the result of level comparison at the vertical blanking period timing (analog timing) obtained from the video signal of the analog television broadcast signal as the switching timing of the switching selection unit 102 to the switching selection unit 102. The switching selection means 102 selects an antenna with a higher signal level and improves reception quality.

  For example, as described in Tetsuya Shimamura, five other authors, Trikes Eps Publishing, and "Program Description of MATLAB Program for Digital Communication Systems" issued in July 2000, the guard interval when receiving digital broadcasts The period has a strong correlation with the previous part of each symbol and is actively used for symbol synchronization, carrier frequency synchronization, etc., so there is a possibility that synchronization will be lost if a switching operation is performed every guard interval. However, for example, in the digital broadcast reception mode, it is not always necessary to set the switching timing to each guard interval period, and the control may be simplified by reducing the switching frequency from the reception level fluctuation state.

  In the present embodiment, the description has been made assuming that the reception bandwidth is 6 MHz. However, the bandwidth is not necessarily 6 MHz, and the first reception unit 105B and the second reception unit 106B can perform electric field level comparison. If it is wide, it does not limit its bandwidth.

  According to the diversity receiving circuit 700 in the second embodiment of the present invention (in the receiving apparatus having the two antennas, a television broadcast receiving means that is not normally used in each receiving mode is used as a level detecting means. Therefore, the diversity receiving circuit 700 can be realized with a relatively simple configuration.

  Furthermore, the switching timing can be generated from the received signal, and errors during switching can be eliminated. Further, since the switching operation is performed only when the electric field level of the non-receiving antenna becomes larger than the electric field level of the receiving antenna, an antenna with a high level can be selected with certainty. Moreover, since level measurement is performed simultaneously for two systems, there is no need to perform an unnecessary switching operation.

According to the diversity receiving circuit 700 in the second embodiment of the present invention, the digital television broadcast signal has the OFDM signal, and the switching control means 110 is based on the guard interval signal included in the OFDM signal. A digital timing generation unit that generates a digital timing for outputting a switching selection signal, or the switching control means 110 generates a switching selection signal based on a vertical blanking period included in an analog television broadcast signal. By having an analog timing generator that generates the output analog timing, it is possible to make it difficult for symbol synchronization to be lost when receiving digital TV, and unnecessary image quality degradation occurs when switching to analog TV receivers. Can be difficult.
(Third embodiment)

Next, a third embodiment of the present invention will be described.
FIG. 8 is a block diagram of a diversity receiving circuit 800 according to the third embodiment of the present invention. In FIG. 8, the same reference numerals as those used in the diversity receiving circuit 700 in the second embodiment have the same names and the same functions, and a description thereof will be omitted.

  Diversity receiving circuit 800 includes power supply control means 130 in addition to diversity receiving circuit 700. The power control unit 130 includes a power control timing generation unit 131 and a power control unit 132. The diversity receiving circuit 800 is different from the diversity receiving circuit 700 in that the power supply control unit 130 is used to stop the power supply of one receiving apparatus at a time other than before and after the switching control.

Hereinafter, the operation of the diversity receiving circuit 800 will be described.
The power control timing generation unit 131 generates a timing for power control using the analog timing or digital timing described in the second embodiment of the present invention as an input signal and outputs the timing to the power control unit 132. The power supply control unit 132 stops the power supply of the second receiving unit 106B according to the mode set by the reception mode setting unit 111, for example, in the digital broadcast signal reception mode, and the first in the analog broadcast signal reception mode. The power of the first receiving means 105B is stopped.

Next, the stop timing of the receiving means in the non-reception mode in which the power is stopped will be described.
FIG. 9 is a diagram showing the stop timing of the reception means in the non-reception mode of the diversity reception circuit 800 according to the third embodiment of the present invention.

First, each control timing in the digital broadcast signal reception mode will be described.
The digital timing 901 is obtained as an output signal of the FFT window setting unit 121, and outputs a signal in the guard interval period with a symbol length period. The switching control signal 902 is a signal that is output when the received signal strength of the currently received antenna exceeds the received signal strength of the other antenna in accordance with the digital timing 901. Here, the switching control signal 902 is switched at every digital timing. The case of controlling is shown. A power control signal 903 is an output signal of the power controller 133.

The time from the falling edge of the switching control signal 902 to the falling edge of the digital timing 901 is ta, the time from the falling edge of the digital timing 901 to the rising edge of the power control signal 903 is tb, and the time from the rising edge of the power control signal 903 to the switching control signal 902 Td represents the operating time of the second receiving means 106B, and the sum of ta and tb (ta + tb) represents the stop time of the second receiving means 106B.

  The state transition state of the second receiving means 106B in the digital reception mode is shown at 904. The time required for starting the second receiving means 106B, that is, the state transition from the reception stop state 906 to the receivable state 907 is shown. If the time required is te, td must be selected such that td> te.

  The operation at the time of digital broadcast reception has been described so far, but the same applies to the operation at the time of analog broadcast reception. The analog timing 901 is used instead of the digital timing, and the vertical blanking period corresponds to the guard interval period of digital broadcasting, and becomes the switching control signal 902.

  Further, a state transition state of the first receiving unit 105B in the analog broadcast signal reception mode is shown in 905, and tf is a time required for starting the first receiving unit 105B, that is, a state where reception is possible from the reception stop state 908. Assuming that the time required for the state transition to 909 is td, td is selected so that td> tf.

  For example, in the digital broadcast reception mode of the present embodiment, the power activation control is performed every guard interval period, but it is not always necessary to perform the power activation every guard interval period, depending on the reception state, The period of the power control signal may be varied.

  Moreover, when using in a portable terminal etc., it is also possible to extend a battery life by changing the frequency of switching control according to a battery remaining charge. Further, when the reception level is sufficiently high, the power supply of the receiving means in the non-receiving state may be stopped. Also, there is power activation control, but it is not always necessary to control the power of all of the receiving means, and if there is an effect of reducing power consumption, even if only a part of the power is activated, or Current control may be used.

According to the diversity receiving circuit 800 in the third embodiment of the present invention, the power control timing generating unit 131 that generates the power control timing for controlling the power based on the digital timing or the analog timing, and the power control timing If the digital television system is selected as the reception mode, power is supplied to the second receiving means 106B. If the analog television system is selected as the reception mode, power is supplied to the first receiving means 105B. By using the power supply control unit 132 that controls the power consumption, the power consumption can be further reduced.
(Fourth embodiment)

Next, a fourth embodiment of the present invention will be described.
FIG. 10 is a block diagram of a diversity receiving circuit 1000 according to the fourth embodiment of the present invention. In FIG. 10, the same reference numerals as those assigned to the diversity receiver circuit 100 in the first embodiment of the present invention have the same names and the same functions, and the description thereof will be omitted.

  Diversity receiving circuit 1000 includes second switching selecting means 133 in place of switching selecting means 102 of diversity receiving circuit 100, and further includes third antenna 101C, fourth antenna 101D, third input terminal 103C, and A fourth input terminal 103D is provided.

  The second switching selection unit 133 is an example of a switching selection unit. The third antenna 101C and the fourth antenna 101D are examples of a plurality of antennas.

  The diversity receiving circuit 1000 is different from the diversity receiving circuit 100 in that the diversity receiving circuit 100 is a diversity receiving circuit that is realized with two antennas, whereas the diversity receiving circuit 1000 has three or more antennas. (4 in the present embodiment) is used, and a diversity receiving circuit 1000 corresponding to a large number of antennas is provided by using a switching unit corresponding to a large number of antennas.

Hereinafter, the operation of the diversity receiving circuit 1000 will be described.
FIG. 11 is a diagram showing changes in the received signal level of each antenna in the fourth embodiment of the present invention.

  In FIG. 11, reference numerals 1101, 1102, 1103, and 1104 represent temporal changes in reception levels at the first antenna 101A, the second antenna 101B, the third antenna 101C, and the fourth antenna 101D, respectively. For the sake of convenience, the description will be made assuming that values other than the reception level change 1101 of the first antenna 101A take a constant value with respect to time. In the second to fourth antennas 101B to 101D, the second antenna 101B, the third antenna 101C, and the fourth antenna 101D are arranged in descending order of reception level.

  In the digital broadcast signal reception mode, the switching control unit 110 controls the second switching selection unit 133 so that the first reception unit 105A has the highest reception level. On the other hand, the second receiving means 106A selects and switches antennas not selected by the first receiving means 105A in order, and monitors the reception level of the antenna.

  FIG. 12 is a diagram showing temporal changes in the outputs of the first reception level detection means 107 and the second reception level detection means 108 in the fourth embodiment of the present invention. The first reception level 1201 (thick dotted line) indicates the reception level detected by the first reception level detection means 107. The second reception level 1202 (thick line) indicates the reception level detected by the second reception level detection means 108. The switching timing 1203 is a signal generated by the switching control unit 110 and indicating the timing for switching the antenna. The level measurement period 1204 of each antenna is a period for measuring the reception level of each antenna, and corresponds to, for example, one cycle of the switching timing 1203. The antenna switching period 1205 is a period during which the antennas sequentially selected by the second receiving unit 106A make a round.

  Measure the reception level of the antenna (here, the second antenna 101B, the third antenna 101C, and the fourth antenna 101D) other than the antenna (here, the first antenna 101A) selected by the first receiving means 105A. In order to do this, the second switching control means 133 switches in turn every clock rise of the switching control timing 1203. Specifically, in this embodiment, switching control is performed in the order of 101C → 101B → 101D, and this is repeated thereafter, and the reception level becomes equal to or higher than the reception level of the first antenna 101A currently selected by the first reception means 105A. If an antenna is found, the first antenna 101A and its antenna are switched at the next clock timing, so that an antenna with a high level can always be selected.

  In the present embodiment, at the ninth clock, the first receiving means 105A switches from the first antenna 101A to the second antenna 101B. Note that the antenna switching period 1205 in which antennas other than the antenna selected by the first receiving means 105A are sequentially switched does not need to be continuously switched as in the switching control timing 1203 as shown in FIG. You may implement for every digital timing in the 2nd Embodiment of this invention.

FIG. 13 is a diagram showing an antenna switching period in the fourth embodiment of the present invention.
The second antenna switching period 1301 is a period from the first digital timing 1304 to the second digital timing 1305. At digital timings 1304 and 1305, a switching timing 1302 is output. The switching timing 1302 has a level measurement period 1204 for each antenna in FIG.

  Between the digital timings 1304 and 1305, data 1303b of the FFT decoded signal 1303 in the FFT window period 1306b is transmitted. Similarly, data 1303a of the FFT decoded signal 1303 in the FFT window period 1306a is transmitted immediately before the digital timing 1304, and data 1303c of the FFT decoded signal 1303 in the FFT window period 1306c is transmitted immediately after the digital timing 1305.

  Note that power consumption may be reduced by stopping the power supply of the second receiving unit 106A in order to save power during the period other than the first digital timing in the second antenna switching period 1301.

  Moreover, although the description at the time of digital television broadcast reception has been given, the same can be applied to the time of analog television broadcast reception. In addition, although the timing of a fixed cycle is used here, the control may be performed by changing the cycle according to the characteristics of the antenna and the reception quality. In the present embodiment, the number of antennas has been described as four, but the same effect can be obtained with four or more antennas.

  According to the diversity receiving circuit 1000 in the fourth embodiment of the present invention, the switching selecting unit 110 selects one of the plurality of antennas as the first receiving unit 105A or the second based on the reception mode. The remaining antennas are selected one by one from the first antenna connection section connected to the receiving means 106A and the remaining antennas that are not connected to the receiving means 105A or 106A among the plurality of antennas, and are switched in order. With the configuration including the second antenna connection unit connected to the reception unit, the antenna having the highest reception level can be selected even in a severe fading environment with a plurality of antennas.

  The present invention is a diversity receiving circuit, a diversity receiving device, a diversity receiving system, etc. that receives a plurality of radio communication system signals, has a relatively simple configuration, consumes less power, and reliably selects an antenna having a high reception level. Useful for.

1 is a block diagram of a diversity receiving circuit according to a first embodiment of the present invention. The figure showing the 1st switching state of the switching selection means in the 1st Embodiment of this invention The figure showing the 2nd switching state of the switching selection means in the 1st Embodiment of this invention Schematic diagram of first receiving means in the first embodiment of the present invention Schematic diagram of second receiving means in the first embodiment of the present invention The figure which showed the control method of the switching control means in the 1st Embodiment of this invention The figure which showed the input signal and control signal in the case of the digital broadcast signal reception mode in the 1st Embodiment of this invention The block diagram of the diversity receiver circuit in the 2nd Embodiment of this invention The block diagram of the diversity receiver circuit in the 3rd Embodiment of this invention The figure which showed the stop timing of the receiving means in the non-reception mode of the diversity receiver circuit in the 3rd Embodiment of this invention The block diagram of the diversity receiver circuit in the 4th Embodiment of this invention The figure which showed the change of the received signal level of each antenna in the 4th Embodiment of this invention The figure which showed the time change of the output of the 1st and 2nd receiving level detection means in the 4th Embodiment of this invention. The figure which showed the antenna switching period in the 4th Embodiment of this invention Diagram showing conventional OFDM transmission symbols

Explanation of symbols

101A first antenna 101B second antenna 101C third antenna 101D fourth antenna 102 switching selection means 103A, 103B input terminals 104A, 104B output terminals 105A, 105B first receiving means 106A, 106B second receiving means 107 first reception level detection means 108 second reception level detection means 109 level comparison means 110 switching control means 111 reception mode setting means 112 first demodulation output terminal 113 second demodulation output terminal 114 video demodulation output terminal 115 audio Demodulation output terminal 116 First tuner unit 117 OFDM demodulation unit 118 AD conversion unit 119 FFT decoding unit 120 Demodulation / decoding unit 121 FFT window setting unit 122 Second tuner unit 123 Band limiting unit 124 Demodulation unit 125 Video reception unit 126 Timing Generation unit 12 Audio receiving unit 128 Reception timing switching unit 129 Switching control unit 130 Power source control unit 131 Power source control timing generation unit 132 Power source control unit 133 Second switching selection unit 301 Band pass filter 302 RF amplifier 303 Mixer 304 Local oscillator 305 Band pass filter 306 AGC
307 A / D converter 308 Baseband unit 401 Bandpass filter 402 RF amplifier 403 Mixer 404 Local oscillator 405 Bandpass filter 406 Analog detector

Claims (10)

A plurality of antennas for receiving communication signals of a plurality of wireless communication methods;
A first receiving unit connected to any one of the plurality of antennas;
A second receiver connected to any one of the plurality of antennas not connected to the first receiver;
The first reception level of the communication signal output from the first reception unit and the second reception level of the communication signal output from the second reception unit are compared, and a level comparison signal indicating the comparison result is output. A level comparison unit,
Based on the reception mode control signal for selecting a reception mode for receiving any one of the communication signals set in advance among the communication signals of the plurality of wireless communication schemes and the level comparison signal, the plurality of antennas receive the first signal from the plurality of antennas. A switching control unit that outputs a switching selection signal that selects antennas connected to the one receiving unit and the second receiving unit one by one;
A diversity reception circuit comprising: a switching selection unit that connects two of the plurality of antennas to the first reception unit or the second reception unit based on the switching selection signal. The diversity receiving circuit according to claim 1,
The plurality of wireless communication systems include a digital TV system and an analog TV system,
The first receiving unit receives the digital television broadcast signal;
The second receiving unit receives the analog television broadcast signal,
A diversity receiving circuit in which the first receiving unit and the second receiving unit have the same reception channel bandwidth. The diversity receiving circuit according to claim 2,
The digital television broadcast signal has an OFDM signal,
The switching control unit
A diversity receiving circuit comprising: a digital timing generation unit that generates a digital timing for outputting the switching selection signal based on a guard interval signal included in the OFDM signal. The diversity receiving circuit according to claim 2,
The switching control unit
A diversity receiving circuit having an analog timing generation unit that generates an analog timing for outputting the switching selection signal based on a vertical blanking period included in the analog television broadcast signal. The diversity receiver circuit according to any one of claims 3 to 4,
Based on the digital timing or the analog timing, a power control timing generation unit that generates a power control timing for controlling the power,
Based on the power control timing, when the digital television system is selected as the reception mode, power is supplied to the second receiving unit, and when the analog television system is selected as the reception mode, the first reception is performed. A diversity receiving circuit comprising: a power control unit that controls power supply to the unit. The diversity receiving circuit according to claim 5,
The switching control unit
When the digital television system is selected as the reception mode, the reception level of the communication signal received by the antenna connected to the first receiving unit is the level of the communication signal received by the antenna connected to the second receiving unit. It has a digital switching control signal that is output when it is greater than the reception level,
The power control timing generation unit
A diversity receiving circuit that generates the power control timing based on the digital switching control signal and the digital timing. The diversity receiving circuit according to claim 5,
The switching control unit
When the analog television system is selected as the reception mode, the reception level of the communication signal received by the antenna connected to the second receiving unit is the level of the communication signal received by the antenna connected to the first receiving unit. Has an analog switching control signal that is output when the reception level is greater than
The power control timing generation unit
A diversity receiving circuit that generates the power control timing based on the analog switching control signal and the analog timing. A diversity receiving circuit according to any one of claims 1 to 7,
The switching selector is
A first antenna connection unit for connecting one of the plurality of antennas to a first reception unit or a second reception unit based on the reception mode;
Diversity comprising: a second antenna connection unit that selects the remaining antennas one by one from the remaining antennas that are not connected to the reception unit in the plurality of antennas, and sequentially switches and connects to the other reception unit Receiver circuit. A plurality of antennas for receiving communication signals of a plurality of wireless communication methods;
A first receiving unit connected to any one of the plurality of antennas;
A second receiver connected to any one of the plurality of antennas not connected to the first receiver;
The first reception level of the communication signal output from the first reception unit and the second reception level of the communication signal output from the second reception unit are compared, and a level comparison signal indicating the comparison result is output. A level comparison unit,
Based on the reception mode control signal for selecting a reception mode for receiving any one of the communication signals set in advance among the communication signals of the plurality of wireless communication schemes and the level comparison signal, the plurality of antennas receive the first signal from the plurality of antennas. A switching control unit that outputs a switching selection signal that selects antennas connected to the one receiving unit and the second receiving unit one by one;
A diversity receiving apparatus comprising: a switching selection unit that connects two of the plurality of antennas to the first reception unit or the second reception unit based on the switching selection signal. A plurality of antennas for receiving communication signals of a plurality of wireless communication methods;
A first receiving unit connected to any one of the plurality of antennas;
A second receiver connected to any one of the plurality of antennas not connected to the first receiver;
The first reception level of the communication signal output from the first reception unit and the second reception level of the communication signal output from the second reception unit are compared, and a level comparison signal indicating the comparison result is output. A level comparison unit,
Based on the reception mode control signal for selecting a reception mode for receiving any one of the communication signals set in advance among the communication signals of the plurality of wireless communication schemes and the level comparison signal, the plurality of antennas receive the first signal from the plurality of antennas. A switching control unit that outputs a switching selection signal that selects antennas connected to the one receiving unit and the second receiving unit one by one;
A diversity reception system comprising: a switching selection unit that connects two of the plurality of antennas to the first reception unit or the second reception unit based on the switching selection signal.

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