JP2008092278A - Diversity receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diversity receiver capable of increasing a C/N improvement effect and efficiently performing a diversity reception even without increasing the number of antennas or the like. <P>SOLUTION: In receiving parts 1, 2, receiving signals of the same desired channel band are selected by channel selection parts 5, 6. The receiving signal A of the receiving part 1 is demodulated by a demodulation part 9, supplied to a synthesizing part 13, the receiving signal B of the receiving part 2 is demodulated by a demodulation part 10 and supplied to the synthesizing part 13. In addition, the receiving signals A, B of the receiving parts 1, 2 are added together by an addition part 7, the added signal C is demodulated by a demodulation part 11 and supplied to the synthesizing part 13. Furthermore, the receiving signals A, B of the receiving parts 1, 2 are subtracted by a subtraction part 8, the subtracted signal D is demodulated by a demodulation part 12 and supplied to the synthesizing part 13. In the synthesizing part 13, diversity synthesis is performed to demodulation signals of four systems from the demodulation parts 9-12, the synthetic signal is demodulated by a demodulation part 14 and output from an output part 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mobile transmission / reception apparatus for receiving a terrestrial digital television broadcast while moving, and in particular, a diversity for efficiently receiving a terrestrial digital television broadcast having a low reception electric field strength with a small number of antennas and tuners. The present invention relates to a receiving device.

  Japan's terrestrial digital television broadcast (hereinafter referred to as ISDB-T broadcast) started on December 1, 2003 in Tomei Osaka. Since ISDB-T broadcasting uses an OFDM (orthogonal frequency division multiplexing) system as a modulation system, it is resistant to multipath and is subjected to time interling. strong. Furthermore, it is possible to select a parameter that is strong against transmission distortion by using a mobile layer or a mobile layer, and a modulation scheme or error correction coding rate. For this reason, reception by a mobile receiver such as a mobile phone of ISDB-T broadcasting or a vehicle-mounted receiver (hereinafter referred to as mobile reception) is expected, and studies of mobile receivers are underway.

  In mobile reception, a diversity technique is generally used. In spatial diversity, a plurality of antennas are placed apart so that fluctuations in received signals from them are uncorrelated, and one of their received outputs (branches) is selected, and these received outputs are combined. . As a synthesis method, a selection synthesis method, an equal gain synthesis method, and a maximum ratio synthesis method are known (see, for example, Non-Patent Document 1).

  The selective combining method is a method in which the branch having the highest reception level (or the best C / N (carrier-to-noise ratio)) is selected and used by switching. The equal gain combining method has the same phase between the branches. In the maximum ratio combining method, the phases between the branches are made in-phase, and each branch is weighted according to its level and added. This is a method for obtaining a diversity combined output in which N is maximized.

  Also, when receiving ISDB-T broadcasts employing the OFDM method, a reception method using diversity is known (see, for example, Patent Document 1).

This receiving method receives an OFDM modulated signal, converts the received signal from the time domain to the frequency domain, extracts a signal for each carrier, demodulates the signal data assigned to each carrier, and obtains each obtained carrier The demodulated data is subjected to diversity combining processing in units of carriers.
Yoshio Karasawa “Radio Wave Propagation Fundamentals for Digital Mobile Communications” Corona First Edition First Edition March 17, 2003 Japanese Patent No. 3389178

  By the way, considering the case where the received electric field strength is small, the above-described selective combining method has no C / N improvement effect, so the equal gain combining method and the maximum ratio combining method are more advantageous. However, these methods have a problem that the number of receivers such as antes must be increased in order to increase the C / N improvement effect. For example, when the maximum ratio combining method of four receiving systems is adopted, four antennas, four channel selection units, and four demodulation units are required.

  An object of the present invention is to provide a diversity receiver capable of solving such a problem and improving the C / N improvement effect and efficiently performing diversity reception without increasing the number of antennas and the like. It is in.

  In order to achieve the above-described object, the present invention provides at least two of signals received by an N-sequence receiving section composed of a receiving antenna and a channel selection section (where N is an integer of 2 or more) and an N-sequence receiving section. M (where M is an integer greater than or equal to 1) arithmetic units that perform arithmetic processing on the received signals from the series receiving units, and (N + M) demodulated signals received from the N series receiving units and the output signals from the arithmetic units Demodulating sections and a combining section for diversity combining the demodulated signals from (N + M) demodulating sections.

  In the present invention, N = 2 and M = 2, and one calculation unit is an addition unit that adds reception signals from two systems of reception units, and the other calculation unit is two systems of reception units. This is a subtracting unit that subtracts the received signal.

  In addition, the present invention includes an automatic gain processing unit so that the channel selection unit of the N system receiving units inputs the received signal from the N system receiving unit to the demodulation unit at an optimal level, and M operation units However, the automatic gain processing unit is provided so that the output signals of the M arithmetic units are input to the demodulation unit at an optimum level.

  In addition, the present invention provides an adjustment unit that adjusts at least one of the phase, delay, and gain of a received signal by one of the two systems of the reception units, and the calculation unit includes: An adder that adds the output signal and the received signal from the other receiving unit of the two systems of receiving units, and the adjusting unit is configured so that the C / N of the output signal of the adding unit is maximized. This adjusts at least one of the phase, delay, and gain of the received signal by one receiving unit.

  In addition, the present invention provides an adjustment unit that adjusts at least one of the phase, delay, and gain of a received signal by one of the two systems of the reception units, and the calculation unit includes: A subtracting unit that subtracts the output signal and a received signal from the other receiving unit of the two systems of receiving units, and the adjusting unit is configured so that the C / N of the output signal of the subtracting unit is maximized. This adjusts at least one of the phase, delay, and gain of the received signal by one receiving unit.

  In the present invention, the signal supplied from the reception unit or the calculation unit is an OFDM signal, and the demodulation unit described above includes an orthogonal demodulation unit that orthogonally demodulates the OFDM signal and converts the signal from the time domain to the frequency domain. The above-described combining unit performs diversity combining on the frequency axis.

  According to the present invention, even in the case of mobile reception by digital broadcast diversity, even when the received electric field strength is small, the C / N improvement effect can be improved with a small number of antennas, and the receivable area can be expanded.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a first embodiment of a diversity receiver according to the present invention, wherein 1, 2 are receivers, 3, 4 are antennas, 5, 6 are channel selectors, 7 is an adder, Is a subtracting unit, 9 to 12 are a demodulating unit, 13 is a synthesizing unit, 14 is a decoding unit, and 15 is an output unit.

  In the first embodiment, as an example, diversity combining of four reception systems is performed using two (two systems) reception units.

  In the figure, there are provided a receiving unit 1 including an antenna 3 and a channel selection unit 103, and two receiving units 2 including a receiving unit 2 including an antenna 4 and a channel selection unit 6, and the antennas 3 and 4 have a predetermined interval. Is provided.

  In the receiving unit 1, a received signal of a digital broadcast of a desired channel band received by the antenna 3 and selected by the channel selection unit 5 (hereinafter, this digital broadcast signal is selected as an ISDB-T broadcast and selected by the channel selection unit. A desired channel band of ISDB-T broadcasting is called a channel selection channel band) A is demodulated by the demodulator 9 and supplied to the combiner 13. Similarly, in the receiving unit 2, the received signal B of the desired channel band (that is, the selected channel band) received by the antenna 4 and selected by the tuning unit 5 is demodulated by the demodulating unit 10, and is sent to the combining unit 13. Supplied.

  Here, the channel selection unit 6 of the reception unit 2 is set to select the same channel band as the channel selection unit 5 in the reception unit 1. Therefore, the reception signals A and B output from the reception units 1 and 2 are ISDB-T broadcast signals of the same channel band.

  The reception signal A of the channel selection channel of the reception unit 1 and the reception signal B of the same channel selection channel of the reception unit 2 are supplied to the addition unit 7 and added, and the addition signal C is demodulated by the demodulation unit 11. It is supplied to the synthesis unit 13. Further, the reception signal A of the channel selection channel of the reception unit 1 and the reception signal B of the same channel selection channel of the reception unit 2 are also supplied to the subtraction unit 8 and subtracted, and the subtraction signal D is demodulated by the demodulation unit 12. Is supplied to the combining unit 13.

  In the synthesizing unit 13, the output signals of the demodulating units 9, 11, 12, and 10 are diversity combined, and the combined signal is decoded by the decoding unit 14 and output from the output unit 15.

  As described above, the first embodiment is a diversity receiving apparatus that uses the two receiving units 1 and 2, and thus the two antennas 3 and 4, and combines the four received signals with the combining unit 13. It is what makes.

  2A is a diagram schematically showing a signal in the receiving unit 1 in FIG. 1, and FIG. 2B is a diagram schematically showing a signal in the receiving unit 2 in the same manner.

In FIG. 2A, the received signal A in the channel band selected by the channel selection unit 5 of the reception unit 1 includes a noise signal _NA when received by the antenna 3. The output reception signal A in the channel selection channel band includes the noise signal N _A5 generated by the channel selection unit 5 or the like. Therefore, the power ratio between the received signal A and the noise signal N _AI is C / N of the received signal A before channel selection by the channel selection unit 5, and the received signal A and the noise signals N _A5 and N _AI , particularly the noise signal. The power ratio with N _A5 is the C / N of the received signal A after channel selection by the channel selection unit 5.

Similarly, as shown in FIG. 2B, the received signal B in the channel band selected by the channel selection unit 6 of the reception unit 2 includes the noise signal _NBI when received by the antenna 4. In addition, the reception signal B in the channel selection channel band output from the channel selection unit 6 includes a noise signal N _B6 generated by the channel selection unit 6 and the like. Therefore, the power ratio between the received signal B and the noise signal N _BI is the C / N of the received signal B before channel selection by the channel selection unit 6, and the received signal B and the noise signals N _B6 and N _BI , particularly the received signal. The power ratio between B and the noise signal N _B6 is C / N of the received signal B after channel selection by the channel selection unit 6.

When the received electric field strength is small, the received signals A and B in the channel band selected by the channel selection units 5 and 6 received by the antennas 3 and 4 have low power, so the channel selection is output from the channel selection units 5 and 6. The influence of the noise signals N _A5 and N _B6 generated by the channel selection units 5 and 6 is dominant in the C / N of the channel reception signals A and B. Therefore, the influence of these noise signals N _A5 and N _B6 will be described below.

Here, since the noise signal N _A5 and the noise signal N _B6 are generated in different tuning units 5 and 6, respectively, there is no correlation. For this reason, if the power of the noise signal mixed in the addition signal C output from the addition unit 7 is equal to the power of the noise signal N _A5 and the noise signal N _B6 generated by the channel selection units 5 and 6, The power of the noise signal output from the adder 7 only increases by approximately 3 dB compared to the power of the noise signal N _A5 and the noise signal N _B6 . Similarly, the power of the noise signal output from the subtracting unit 8 only increases by approximately 3 dB as compared with the power of the noise signal N _A5 and the noise signal N _B6 .

On the other hand, if the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 are completely in phase and have the same power, the power of the addition signal C output from the addition unit 7 is This is twice that of signals A and B, resulting in an increase of 6 dB. At this time, the noise signal output from the adder 7 only increases by approximately 3 dB as compared with the power of the noise signal N _A5 or noise signal N _B6 generated by the channel selection units 5 and 6 as described above. The addition signal C output from the unit 7 has a higher C / N than the reception signals A and B output from the channel selection units 5 and 6. Note that, in the subtraction unit 8, the reception signal A and the reception signal B cancel each other, so that the output of the subtraction signal D that is output is zero.

  Therefore, in this case, the signals A and B received from the receivers 1 and 2, the addition signal C output from the adder 7, and the subtraction signal D output from the subtractor 8 are output from the adder 7. C / N of the added signal C to be maximized, and C / N is improved.

Further, assuming that the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 are completely opposite in phase and have the same power, the power of the subtraction signal D output from the subtractor 8 is This is twice the received signals A and B, increasing 6 dB. At this time, the noise signal output from the subtracting unit 8 only increases by approximately 3 dB as compared with the power of the noise signal N _A5 and the noise signal N _B6 generated in the channel selecting units 5 and 6 as described above. The subtraction signal D output from the unit 8 has a higher C / N than the reception signals A and B output from the channel selection units 5 and 6. In addition, in addition part 7, since received signal A and received signal B cancel each other, output received signal C has zero power.

  Therefore, in this case, the received signals A and B from the receiving units 1 and 2, the added signal C output from the adding unit 7, and the subtracted signal D output from the subtracting unit 8 are output from the subtracting unit 8. C / N of the subtraction signal D to be maximized, and C / N is improved.

  Further, when the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 are in a phase relationship different from the in-phase or anti-phase, the addition signal C output from the addition unit 7 And the C / N of the subtraction signal D output from the subtraction unit 8 is slightly improved. However, when the phase relationship between the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 deviates greatly from the in-phase or reverse layer, the addition signal of these reception signals A and B C and the subtraction signal D are meaningless signals.

  Further, when the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 are affected by other than the phase difference, the addition signal C or subtraction output from the addition unit 7 It is unclear whether or not the subtraction signal D output from the unit 8 has an improved C / N over the received signals A and B.

  In the synthesizer 13, 4 of the received signal A demodulated by the demodulator 9, the received signal B demodulated by the demodulator 10, the addition signal C demodulated by the demodulator 11, and the subtracted signal demodulated by the demodulator 12. A demodulated signal whose C / N is improved by selecting a demodulated signal having the maximum C / N or by combining these four demodulated signals with equal gain combining or maximum ratio combining to perform diversity combining. Is output. The demodulated signal is decoded by the decoding unit 14 and output from the output unit 15.

  However, when the reception signal A output from the channel selection unit 5 and the reception signal B output from the channel selection unit 6 are affected by other than the phase difference, the signal is output from the addition unit 7 as described above. It is unclear whether the addition signal C or the subtraction signal D output from the subtraction unit 8 has an improved C / N over the reception signals A and B.

  As described above, in the first embodiment, the C / N of the received signal can be improved. Therefore, even when the received electric field strength is low, the C / N is improved and the reception of the selected channel band with good quality is achieved. A signal can be obtained.

If the noise signals N _AI and N _BI received by the antennas 3 and 4 in FIG. 2 are also uncorrelated, the strength of the received electric field strength and the noise signal N _A5 generated by the tuning unit 5 and the noise signal N _AI Regardless of the magnitude relationship between the noise signal N _BI and the noise signal N _B6 generated in the channel selection section 5, the C / N improvement effect can be obtained for these noise signals N _AI and N _BI . .

  FIG. 3 is a block diagram showing a second embodiment of the diversity receiver according to the present invention, in which 16 and 17 are channel selection units, 18 is an addition unit, 19 is a subtraction unit, and 20 to 23 are demodulation units. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals and redundant description is omitted.

  In the second embodiment, for example, diversity combining of four reception systems is performed using two reception units, and the basic configuration is the same as that of the first embodiment shown in FIG. .

  In FIG. 3, the channel selection unit 16 of the reception unit 1 includes automatic gain processing means, and the demodulation unit 20 to which the reception signal A of the channel selection channel band output from the channel selection unit 16 is supplied generates a gain control signal. The control signal generating means is provided. This control signal generating means outputs a gain control signal for controlling the gain of the automatic gain processing means of the channel selection unit 16 so that the level of the reception signal of the channel selection channel band supplied to the demodulation unit 20 becomes an optimum constant level. appear.

  The channel selection unit 17 of the reception unit 2 includes automatic gain processing means, and the demodulation unit 21 supplied with the reception signal B of the channel selection channel band output from the channel selection unit 17 generates a control signal for generating a gain control signal. Means. This control signal generating means outputs a gain control signal for controlling the gain of the automatic gain processing means of the channel selection unit 17 so that the level of the reception signal of the channel selection channel band supplied to the demodulation unit 21 becomes an optimum constant level. appear.

  The adder 18 includes automatic gain processing means, and the demodulator 22 supplied with the addition signal C output from the adder 18 includes control signal generating means for generating a gain control signal. This control signal generating means outputs a gain control signal for controlling the gain of the automatic gain processing means of the adder 18 so that the level of the received signal in the channel selection channel band supplied to the demodulator 22 becomes an optimum constant level. appear.

  The subtracting unit 19 includes an automatic gain processing unit, and the demodulating unit 23 supplied with the subtracted signal D output from the subtracting unit 19 includes a control signal generating unit that generates a gain control signal. This control signal generating means outputs a gain control signal for controlling the gain of the automatic gain processing means of the subtracting section 19 so that the level of the received signal of the channel selection channel band supplied to the demodulating section 23 becomes an optimum constant level. appear.

  Note that, by such automatic gain processing, the input signals of the demodulating units 20 to 23 are converted into signals having the same level.

  The demodulated signals from the demodulating units 20 to 23 are supplied to the synthesizing unit 13, and a demodulated signal with the maximum C / N or demodulated signal by the maximum ratio synthesis is obtained as in the first embodiment shown in FIG.

  As described above, in the second embodiment, the same effects as those of the first embodiment can be obtained, and the input levels of the demodulation units 20 to 23 are set to optimum levels. The accuracy of the demodulating operations 20 to 23 is improved, and the synthesizing unit 13 can process the demodulated signal demodulated by the high-accuracy demodulating operation, and the accuracy of the processing of the synthesizing unit 13 is also improved.

  In the embodiment shown in FIGS. 1 and 3, three or more receiving units are used, one or more sets of the adding unit 7 and the subtracting unit 8 are provided, and each receiving unit, each adding unit, and each subtracting unit are provided. In addition, a demodulating unit may be provided in the above, so that the number of demodulated signals exceeding the number of systems of the receiving unit may be diversity combined.

  FIG. 4 is a block diagram showing a third embodiment of the diversity receiver according to the present invention. In FIG. 4, reference numeral 24 denotes a signal adjustment unit, and parts corresponding to those in FIG. To do.

  In the third embodiment, as an example, diversity combining of three reception systems is performed using two reception units.

  In FIG. 4, in the adder 7, the received signal A in the selected channel band output from the receiver 1 and the received signal B in the selected channel band output from the receiver 2 are phase and delayed by the signal adjusting unit 24. , At least one of the gains is adjusted and added. The signal adjustment unit 24 includes detection means for detecting the level or C / N of the addition signal C output from the addition unit 7, and the level or C / N of the addition signal C detected by the detection means is The reception signal B from the reception unit 2 is adjusted so as to be maximized.

  In the third embodiment, the subtracting unit 8 in FIG. 1 and the demodulating unit 12 that demodulates the output thereof are not provided, and three demodulated signals of the demodulating units 9 to 11 are supplied to the synthesizing unit 13. A demodulated signal with an improved C / N is output by processing the demodulated signal of the system and selecting the one with the largest C / N or combining the demodulated signals of these three systems with the maximum ratio.

  As described above, in the third embodiment, the received signal is received even if the ISDB-T broadcast signal is received with the low reception electric field strength, as in the previous embodiment, while the diversity combining of the demodulated signals of the three systems is performed. C / N can be improved, and a reception signal of good quality can be decoded by the decoding unit 14.

  In the third embodiment, as in the second embodiment shown in FIG. 3, the channel selection units 5 and 6 and the addition unit 7 are provided with automatic gain processing means, and the demodulation units 9, 10, 11 Gain processing is performed so that the received signals A and B input to the demodulating units 9 and 10 and the addition signal C supplied to the demodulating unit 11 are at the optimum level by the gain control signal from the control signal generating unit. It can also be.

  Further, by using three or more receiving units, providing one or more systems including the adding unit 7, the signal adjusting unit 24, and the demodulating unit 11, and further providing a demodulating unit for each receiving unit and each adding unit, the receiving unit Diversity combining may be performed for a number of demodulated signals exceeding the number of systems.

  At this time, adjustment of the signal adjustment unit 24 may be a single function such as only the phase, only the delay, or only the gain.

  FIG. 5 is a block diagram showing a fourth embodiment of the diversity receiver according to the present invention. The parts corresponding to those in FIG. 1 and FIG.

  In the fourth embodiment, as an example, diversity combining of three reception systems is performed using two reception units.

  In FIG. 5, the subtracting unit 8 adjusts the delay amount of the received signal B of the selected channel band output from the receiving unit 2 to the received signal A of the selected channel band output from the receiving unit 1 by the signal adjusting unit 24. The signal adjusting unit 24 includes a detecting unit that detects the level or C / N of the subtracted signal D output from the subtracting unit 8. The reception signal B from the reception unit 2 is adjusted for at least one of phase, delay, and gain so that the level or C / N of the detected subtraction signal D is maximized.

  In the fourth embodiment, when the same disturbing signal jumps into the antennas 3 and 4 or the receiving units 1 and 2 respectively, or when the same disturbing signal is generated in the receiving units 1 and 2 for some reason, this disturbing signal is generated. Is subtracted by the subtracting unit 8, and the signal adjustment unit 24 reduces the received signal B from the receiving unit 2 so that the cancelled interference signal is minimized or the C / N deterioration due to the new disturbance is minimized. Adjustment is made for at least one of phase, delay, and gain.

  In the fourth embodiment, the adder 7 in FIG. 1 and the demodulator 11 that demodulates the output thereof are not provided, and three demodulated signals of the demodulator 9, 10, and 12 are supplied to the synthesizer 13. These three systems of demodulated signals are processed and the one with the largest C / N is selected, or these three systems of demodulated signals are combined at the maximum ratio to output a demodulated signal with improved C / N.

  In the fourth embodiment, when the same disturbing signal jumps into the receiving units 1 and 2 or when the same disturbing signal is generated at the receiving units 1 and 2, the interference canceling effect of the subtracting unit 8 is achieved. As a result, C / N may be improved and expected.

  As described above, in the fourth embodiment, the diversity combining of the demodulated signals of the three systems is performed, but even if the ISDB-T broadcast signal is received with a low reception electric field strength as in the previous embodiment, the reception is also possible. Even when the same disturbing signal jumps into or is generated in the units 1 and 2, the C / N of the received signal can be improved, and the received signal of good quality can be decoded by the decoding unit 14. .

  Here, a fixed delay may be added to the reception signal A side so that the signal adjustment unit 24 can relatively adjust the reception signal B more advanced than the reception signal A. May be provided on the side where the reception signal A of the subtraction unit 8 is input, and the reception signal A input to the subtraction unit 8 may be delay-adjusted.

  In the fourth embodiment, as in the second embodiment shown in FIG. 3, the channel selection units 5 and 6 and the subtraction unit 8 are provided with automatic gain processing means, and the demodulation units 9, 10, 12 Gain processing is performed so that the received signals A and B input to the demodulating units 9 and 10 and the subtraction signal D supplied to the demodulating unit 12 are at the optimum level by the gain control signal from the control signal generating unit. It can also be.

  Further, by using three or more receiving units, providing one or more systems including the subtracting unit 8, the signal adjusting unit 24, and the demodulating unit 12, and further providing a demodulating unit for each receiving unit and each subtracting unit, the receiving unit Diversity combining may be performed for a number of demodulated signals exceeding the number of systems.

  At this time, the signal adjustment unit 24 may be adjusted to have a single function such as only the phase, only the delay, or only the gain.

  FIG. 6 is a block diagram showing a specific example of the demodulating units 9 to 12 and 20 to 23 when receiving the ISDB-T broadcast in each of the previous embodiments. A D (analog / digital) converter, 27 is an orthogonal demodulator, and 28 is an FFT (fast Fourier transform) unit.

  In the figure, received signals A and B of a desired channel selection band of ISDB-T broadcast from the previous channel selection units 5, 6, 16 and 17, or an addition signal C from the addition units 7 and 18, or a subtraction unit The subtraction signals D from 8 and 19 are input to the demodulator 25 and converted to digital signals by the A / D converter 26. This digital signal is converted into a baseband signal by the orthogonal demodulation unit 27, converted from a time domain signal to a frequency domain signal by the FFT unit 28, and output from the demodulation unit 25 as a demodulated signal. This demodulated signal is supplied to the synthesizer 13 (FIGS. 1, 3, 4, and 5).

  The ISDB-T broadcast signal is an OFDM signal, and by being converted into a frequency domain signal, diversity combining such as maximum ratio combining can be performed on the signal for each carrier.

  As mentioned above, although embodiment of this invention was described, this invention is not limited only to this embodiment, You may deform | transform these.

  That is, in the third embodiment shown in FIG. 4, the signal adjustment unit 24 having the above-mentioned level or C / N detection means is provided on the input side of the reception signal A in the addition unit 7 and is input to the addition unit 7. At least one of the phase, delay, and gain of the received signal A may be adjusted.

  Further, in the second embodiment shown in FIG. 3, a signal adjustment unit including the above-mentioned level or C / N detection means is provided on the input side of the reception signal A or the input side of the reception signal B in the addition unit 18, At least one of the phase, delay, and gain of the received signal A or the received signal B is adjusted and supplied to the adder 18, and the above level is applied to the input side of the received signal A or the input side of the received signal B in the subtractor 19. Alternatively, a signal adjustment unit including a C / N detection unit may be provided, and at least one of the phase, delay, and gain of the reception signal A or the reception signal B may be adjusted and supplied to the subtraction unit 19. In this way, by supplying the reception signal A or the reception signal B that has been delay-adjusted to the subtracting unit 19, the interference signal mixed in the reception signals A and B is effectively obtained as in the fourth embodiment shown in FIG. The effect of canceling is obtained.

  Further, in the third embodiment shown in FIG. 4 and the fourth embodiment shown in FIG. 5, the signal adjustment unit 24 may be omitted if phase adjustment, delay adjustment, and gain adjustment are not necessary. If the required phase adjustment amount, delay adjustment amount, and gain adjustment amount are fixed values, those having a fixed phase, those having a fixed delay, and those having a fixed gain may be used. This also applies to the second embodiment shown in FIG. 3 when the phase adjustment unit, the delay adjustment unit, or the gain adjustment unit is provided as described above.

  In the above embodiment, mobile reception of ISDB-T broadcasting is taken as an example. However, the present invention is not limited to this, and is applicable to mobile reception for all signal transmissions. Needless to say, the mobile receiver may be a receiver (such as a mobile phone) carried by a person or a receiver mounted on any mobile body such as an automobile, a train, or a ship.

It is a block block diagram which shows 1st Embodiment of the diversity receiver by this invention. It is a figure which shows roughly the relationship between the output received signal and noise signal in the receiving part in FIG. It is a block block diagram which shows 2nd Embodiment of the diversity receiver by this invention. It is a block block diagram which shows 3rd Embodiment of the diversity receiver by this invention. It is a block block diagram which shows 4th Embodiment of the diversity receiver by this invention. It is a block block diagram which shows one specific example of the demodulation part in the case of receiving ISDB-T broadcast in FIG. 1, FIG. 3-FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Receiving part 3, 4 Antenna 5, 6 Channel selection part 7 Addition part 8 Subtraction part 9-12 Demodulation part 13 Synthesis part 14 Decoding part 15 Output part 16, 17 Channel selection part 18 Addition part 19 Subtraction part 20-23 Demodulation part 24 signal adjustment unit 25 demodulation unit 26 A / D conversion unit 27 orthogonal demodulation unit 28 FFT unit

Claims (6)

A receiving unit of an N series (where N is an integer of 2 or more) composed of a receiving antenna and a tuning unit;
M (where M is an integer greater than or equal to 1) arithmetic units that perform arithmetic processing on reception signals from at least two series of reception units among reception signals by the N-sequence reception units;
(N + M) demodulation units that demodulate a reception signal of the N-sequence reception unit and an output signal of the calculation unit;
A diversity receiving apparatus comprising: a combining unit that performs diversity combining of demodulated signals from the (N + M) demodulating units. In claim 1,
N = 2, M = 2,
One of the calculation units is an addition unit that adds reception signals from the two reception units.
The other calculation unit is a subtraction unit that subtracts reception signals from the two reception units. Diversity reception apparatus, wherein: In claim 1 or 2,
The channel selection unit of the N system reception units includes an automatic gain processing unit so that a signal received by the N system reception unit is input to the demodulation unit at an optimal level,
The diversity receiving apparatus, wherein the M calculation units include an automatic gain processing unit so that output signals of the M calculation units are input to the demodulation unit at an optimum level. In claim 1,
An adjustment unit is provided that adjusts at least one of a phase, a delay, and a gain of a reception signal by one of the two reception units.
The calculation unit is an addition unit that adds an output signal of the adjustment unit and a reception signal from the other reception unit of the two systems of reception units,
The diversity unit adjusts at least one of a phase, a delay, and a gain of a received signal by the one receiving unit so that the C / N of the output signal of the adding unit is maximized Receiver device. In claim 1,
An adjustment unit is provided that adjusts at least one of a phase, a delay, and a gain of a reception signal by one of the two reception units.
The calculation unit is a subtraction unit that subtracts an output signal of the adjustment unit and a reception signal from one of the two reception units.
The diversity unit adjusts at least one of a phase, a delay, and a gain of the received signal by the one receiving unit so that the C / N of the output signal of the subtracting unit is maximized Receiver device. In any one of Claims 1-5,
The signal supplied from the receiving unit or the arithmetic unit is an OFDM signal,
The demodulation unit includes an orthogonal demodulation unit that orthogonally demodulates the OFDM signal and converts the signal from a time domain to a frequency domain,
The diversity receiver is characterized in that the combining section performs diversity combining on the frequency axis.

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