JP2018037742A - Shared polarization converter, receiver and satellite receiver unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shared polarization converter, a receiver and a receiver unit which enable the removal of interference components of cross polarization in receiving digital signals transmitted by utilization of a plurality of kinds of polarization.SOLUTION: An interference removing receiver 3 according to the present invention comprises: an interference-removal type shared polarization converter 31; and an interference-removal type receiver 32. The interference-removal type shared polarization converter 31 has a relative frequency conversion part 313 operable to transmit relative intermediate frequency signals of respective local oscillating frequency signals of right-turning and left-turning frequency conversion parts 311, 312. The interference-removal type receiver 32 has: first and second interference wave replica signal generation parts 321, 322 operable to generate replica signals of interference waves; a desired wave signal processing part 323 operable to remove interference waves from desired waves; and a relative frequency error estimation part 324 operable to estimate, based on relative intermediate frequency signals, a frequency error thereof. With the aid of the relative frequency conversion part 313 and the relative frequency error estimation part 324, it becomes possible to keep down the interference waves to the desired waves with frequency synchronization achieved with high accuracy.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarization sharing converter, a receiver, and a satellite receiver that receive a digital signal transmitted using a plurality of types of polarized waves.

  In satellite broadcasting systems and satellite communication systems, right-handed and left-handed circularly polarized waves and horizontal and vertical linearly polarized waves are used for effective use of frequency resources. Thereby, signals for two channels can be transmitted in the same frequency band.

  For example, in a satellite broadcasting system, as shown in FIG. 6, a digital signal is transmitted from a satellite transmitter 1 to a satellite repeater 2 of a real satellite while sharing a right-handed and left-handed circularly polarized wave. 2 relays this digital signal and transmits it to the satellite receiver 3.

  Here, in the satellite transmission path via the satellite repeater 2, as shown in FIG. 8 (A), the odd-numbered right-handed circularly polarized wave and the even-numbered left-handed circularly polarized wave have the center frequency of each channel as the channel interval. The left and right turns are alternately arranged so as to be half (19.18 MHz) of (38.36 MHz). When receiving the right-handed circularly polarized wave and the left-handed circularly polarized wave with the satellite repeater 2 or the satellite receiver 3, the amplitude level of the differently polarized wave is suppressed to some extent because it is identified by the polarized wave (cross-polarized wave identification). The main polarization can be received in the state. In order to receive the right-handed circularly polarized wave and the left-handed circularly polarized wave signal (broadcast wave signal) transmitted from the satellite repeater 2, the satellite receiver 3 receives the right-handed and left-handed circularly polarized waves as receiving antennas. It is known that if a parabolic antenna shared by waves is used, one unit can receive broadcast services of both polarizations (see, for example, Non-Patent Document 1).

  For example, the satellite receiver 3 applies the right-handed and left-handed circularly polarized wave signals received via the dual-polarization receiving antenna (not shown) as disclosed in Non-Patent Document 1 to FIG. As shown in FIG. 2, the dual-polarization converter 31 that performs frequency conversion and the receiver 32 that performs demodulation and decoding are configured.

  The polarization sharing converter 31 includes a right-handed frequency converter 311 and a left-handed frequency converter 312 as main components.

  In the right-handed frequency converter 311, when a downlink right-handed circularly polarized modulated wave signal is input from the satellite repeater 2, a 12 GHz-band right-handed circularly polarized wave is output by a bandpass filter (BPF) 3111. The excess noise component is removed from the modulated wave signal, and the mixer 3113 converts the frequency into the right-hand circularly polarized BS-IF band based on the local oscillation frequency signal from the local oscillator 3114. Then, the band-pass filter (BPF) 3112 uses an extraneous frequency-polarized BS-IF band intermediate frequency signal obtained through the mixer 3113 (referred to as a “right-handed IF signal” in the present specification) by the bandpass filter (BPF) 3112. Noise components are removed. As a more specific example, the right-handed frequency conversion unit 311 generates a right-hand circularly polarized modulated wave signal in the 12 GHz band (11.7 to 12.75 GHz) in the BS-IF band (1032.23 to 2070.25 MHz). ) To the right-handed IF signal.

  When the left-handed circularly-polarized modulated wave signal input from the satellite repeater 2 is input to the left-handed frequency conversion unit 312, the left-handed circularly-polarized modulated wave in the 12 GHz band is output by the bandpass filter (BPF) 3121. An excess noise component is removed from the signal, and the mixer 3123 converts the frequency into a left-handed circularly polarized BS-IF band based on the local oscillation frequency signal from the local oscillator 3124. The bandpass filter (BPF) 3122 adds extra noise to the intermediate frequency signal in the BS-IF band of the left-handed circular polarization obtained through the mixer 3123 (referred to as “left-handed IF signal” in the present specification). Ingredients are removed. As a more specific example, in the left-handed frequency conversion unit 312, the left-hand circularly polarized modulated wave signal in the 12 GHz band (11.7 to 12.75 GHz) is in the BS-IF band (2224.41 to 22223.25 MHz). Frequency conversion to left-handed IF signal.

  The right-handed IF signal and the left-handed IF signal of each channel of the BS-IF band obtained by frequency conversion and filtering by the right-handed frequency converter 311 and the left-handed frequency converter 312 are as shown in FIG. There is no overlap due to different polarizations, and the polarization sharing converter 31 synthesizes by performing amplitude amplification (not shown) of substantially the same gain for each of the right-handed IF signal and the left-handed IF signal in the BS-IF band, The signal is transmitted to the receiver 32 by one coaxial cable 4.

  The receiver 32 performs frequency selection on a channel desired by the user for a right-handed IF signal and a left-handed IF signal arranged in the BS-IF band by a bandpass filter (BPF) 3231, and analog / digital (A / D) Symbols on the orthogonal coordinates of the I axis (in-phase component with respect to the carrier wave) and the Q axis (phase component orthogonal to the carrier wave) which are digitized (quantized) based on the sampling clock (CLK) by the conversion unit 3232 It is converted into an IQ digital signal represented by Thereafter, in the receiver 32, the demodulation unit 3233 performs demodulation processing corresponding to the modulation processing by the satellite transmission device 1 on the IQ digital signal.

  In general, the demodulator 3233 is provided with a complex multiplier, an automatic gain adjuster, a waveform equalizer, and the like, although not shown, and a symbol reproducing unit 32331 and a carrier reproducing unit 32332. The symbol reproducing unit 32331 reproduces symbols in order to acquire symbol synchronization for the quantized IQ digital signal, and controls to detect and correct a phase error with respect to the sampling clock (CLK). The carrier reproducing unit 32332 is a numerically controlled oscillator (NCO: Numerically Controlled Oscillators) used for carrier reproduction that is used when the IQ digital signal is subjected to complex multiplier processing and waveform equalization from the received phase rotation amount at the signal point position of the synchronization symbol. ) To detect and correct the frequency error.

  Thereafter, in the receiver 32, the decoding unit 3236 performs a decoding process corresponding to the error correction encoding process by the satellite transmission apparatus 1 on the demodulated IQ digital signal, and an external receiver (not shown) is used as an output signal. Is output.

  Incidentally, in the configuration of the receiver 32 shown in FIG. 7, each of the right-handed circularly polarized wave and the left-handed circularly polarized wave signal has the same symbol rate, the same modulation scheme, and the same error correction coding process ( A single A / D converter 3232 based on the same symbol rate, a single demodulator 3233 based on the same modulation scheme, and the same error correction coding An example of a single decoding unit 3236 based on processing will be described.

  However, when each of the right-handed circularly polarized wave and the left-handed circularly polarized wave is a different symbol rate, a different modulation method, and a different error correction coding process (including a case where the coding rate is different), reception is performed. The machine 32 needs to have separate signal processing systems (signal processing systems each including an A / D conversion unit, a demodulation unit, and a decoding unit) for right-handed circular polarization and for left-handed circular polarization. .

  For example, the satellite transmission device 1 uses different modulation schemes for the right-handed circularly polarized wave of the odd-numbered channel and the left-handed circularly polarized wave of the even-numbered channel shown in FIG. As described above, the digital signal is encoded and modulated and transmitted so that the right-handed circularly polarized wave of the odd channel has a lower required C / N (Carrier to Noise) than the left-handed circularly polarized wave of the even-numbered channel. Can do. An individual modulation scheme and coding rate can be arbitrarily set for each channel.

  At this time, the cross polarized wave may become an interference wave with respect to the desired wave of the desired channel, and the level difference between the desired wave and the cross polarized wave is the cross polarization discrimination (XPD) and XPS (Cross Polarization Discrimination). The cross polarization discrimination degree of the antenna for receiving satellite broadcasting in a general home is about 20 dB in fine weather.

  In the broadcasting system ISDB-S (Integrated Services Digital Broadcasting for Satellite) used in the current BS (Broadcasting Satellite) digital broadcasting and broadband CS (Communications Satellite) digital broadcasting, the modulation scheme TC8PSK (Trellis Coded 8 Phase-Shift) Keying), coding rate 2/3 is adopted, and the required C / N is 10.7 dB.

  On the other hand, as a transmission method for an ultra-high-definition television service, which is a high-quality service exceeding HDTV (High-definition television), an advanced broadband satellite digital broadcast of the standard ARIB STD-B44 (for example, see Non-Patent Document 2). The use of a modulation scheme 16APSK (Amplitude and Phase-Shift Keying) based on the transmission path coding scheme of 8K Super Hi-Vision, an ultra-high-definition television service, is assumed to have a transmission speed of about 100 Mbps, and the required C / N of 16APSK corresponding to the transmission speed is 12 dB or more. / N is about 18 dB.

Nagasaka et al., “Prototype of right / left-handed circularly polarized wave receiving antenna for satellite broadcasting”, Imaging Science Technical Report, Vol.39, No.28, BCT2015-60, pp.37-40, 2015 "Transmission method of advanced broadband satellite digital broadcasting standard ARIB STD-B44 2.1 version", [online], revised on March 25, 2016, ARIB, [searched on May 20, 2016], Internet <URL: http : //www.arib.or.jp/english/html/overview/doc/2-STD-B44v2_1.pdf>

  As described above, in the satellite broadcasting system, a digital signal is transmitted from the satellite transmission device 1 to the satellite repeater 2 of the real satellite using the right-handed and left-handed circularly polarized waves. The digital signal is relayed and transmitted to the satellite receiver 3. The signal input to the satellite receiver 3 is C / (N + I) [dB] by adding the interference component I and the noise component N to the desired wave C [dB]. The relationship between C / (N + I) and C / N [dB] and C / I [dB] is expressed by the following equation.

  As expressed by the above formula, when the cross polarization discrimination (XPD) is small, C / I becomes small. Therefore, C / (N + I) when cross polarization exists is small, and the required C / N is reduced. The margin of reception C / N (reception margin of the desired wave) becomes small.

  That is, when the cross polarization discrimination (XPD) is small, the reception C / N margin is small, and conversely, when the cross polarization discrimination (XPD) is large, the reception C / N margin is also large. Further, when the amount of interference is the same, the influence exerted depends on the required C / N value of the parameters (modulation method and coding rate) of the transmission signal.

  For example, the required C / N in the modulated wave signal (TC8PSK, coding rate 2/3) of the current BS digital broadcasting is 10.7 dB, and there is almost no influence when the cross polarization discrimination degree is 20 dB or more. On the other hand, the required C / N for one of the modulated wave signals (32 PSK, coding rate 4/5) standardized by the standard ARIB STD-B44 is 17.4 dB (see Non-Patent Document 2). Degradation due to cross polarization interference is about 1.8 dB.

  In particular, when each of the right-handed circularly polarized wave and the left-handed circularly polarized wave is a different symbol rate, a different modulation scheme, and an error correction coding process with a different coding rate, the higher the symbol rate, A higher required C / N tends to be required as the modulation multi-level number (modulation order) is larger and the coding rate value is larger. For this reason, it is desirable to remove or suppress the cross-polarized wave (interference wave) having a cross-polarized wave discrimination degree higher than the required C / N determined by these factors from the desired wave.

  Therefore, when cross polarization interference occurs in the desired wave, a technique is desired that removes the interference wave component and suppresses the required C / N deterioration, and particularly the interference wave component for the desired wave having a high required C / N. It is desirable to have a technique for removing the above.

  In view of the above problems, an object of the present invention is to provide a satellite receiver capable of removing cross-polarized interference components when receiving a digital signal transmitted using a plurality of types of polarized waves. It is in.

  A dual-polarization converter according to the present invention is a dual-polarization converter that converts a modulated wave signal of a radio frequency band of a digital signal transmitted using a plurality of types of polarization into a signal of an intermediate frequency band, and is a satellite transmission A first modulated wave signal of a first polarization in a predetermined radio frequency band received via a path is converted into an intermediate frequency signal in a first band of an intermediate frequency band based on a local oscillation frequency signal of a first local oscillator. The second polarization band of the intermediate frequency band based on the local oscillation frequency signal of the second local oscillator, with the frequency conversion means and the second polarization modulated wave signal of the predetermined radio frequency band received via the satellite transmission path A second frequency converting means for converting to an intermediate frequency signal of the first local oscillator, a third local oscillation frequency signal using each of the local oscillation frequency signals of the first local oscillator and the second local oscillator, and generating the third local oscillation frequency signal, One polarization and the second polarization A relative frequency converting means for generating a relative intermediate frequency signal by frequency-converting one of the modulated wave signals based on the third local oscillation frequency signal; and an intermediate frequency signal of the first band Output means for outputting the intermediate frequency signal of the second band and the relative intermediate frequency signal to a receiver via a predetermined cable.

  In the polarization sharing converter of the present invention, the digital signal is transmitted as a broadcast wave using a plurality of types of polarization.

  In the dual-polarity converter according to the present invention, the predetermined cable is a coaxial cable, and the output means includes the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal. Are combined and output to the receiver via the coaxial cable.

  In the dual-polarity converter according to the present invention, the modulated wave signal having a higher required C / N ratio among the modulated waves signals of the first polarization and the second polarization is subject to interference wave removal by different polarization. It is comprised so that it may become.

  In the dual-polarity converter of the present invention, the modulation wave signal selected by the selection signal from the receiver among the modulation signals of the first polarization and the second polarization is interfered with by different polarizations. It is configured to be a wave removal target.

  Furthermore, the receiver of the present invention receives the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal output from the dual polarization converter of the present invention, and A receiver capable of removing an interference wave in one or both of modulated wave signals of the first polarization and the second polarization, wherein the first band based on the first polarization And processing the channel in the intermediate frequency signal in either one of the intermediate frequency signal of the second band based on the second polarized wave and the second frequency band as a desired wave to generate an IQ digital signal, Desired wave signal processing means for deriving a desired wave frequency error by carrier recovery, and interference waves caused by channels of different polarizations adjacent to the desired wave channel at a lower frequency are targeted for removal. A first interference wave replica signal generating means for processing an intermediate frequency signal of the channel of the different polarization and generating a first interference wave replica signal as an IQ digital signal; adjacent to the channel of the desired wave at an upper frequency The second interference wave replica signal generating means for processing the intermediate frequency signal of the differently polarized channel as a target for removing the interference wave caused by the differently polarized channel and generating a second interference wave replica signal as an IQ digital signal And a local oscillation frequency signal of the first local oscillator and the second local oscillator by carrier recovery after being generated as an IQ digital signal based on the relative intermediate frequency signal in the frequency band corresponding to the channel of the desired wave Relative frequency error estimation means for deriving an estimation frequency error for estimating a relative frequency error of the local oscillation frequency signal of Control means for controlling the generation of the first interference wave replica signal and the second interference wave replica signal in accordance with a change in the relative frequency error estimated from the desired wave frequency error and the estimation frequency error. It is characterized by that.

  In the receiver according to the present invention, the first interference wave replica signal generation means may be configured such that the channel interval is equal to an IQ digital signal of an intermediate frequency signal of a channel of a different polarization adjacent to the desired wave channel at a lower frequency. The first interference wave replica signal is subjected to complex multiplication by adding a value obtained by subtracting the estimation frequency error from the desired wave frequency error with reference to a negative frequency corresponding to half the value of the first half wave, and adjusting the amplitude and phase delay. The second interference wave replica signal generating means generates a positive frequency corresponding to a half value of a channel interval with respect to an IQ digital signal of an intermediate frequency signal of a channel of a different polarization adjacent to the desired wave channel at an upper frequency. The amplitude and phase delay are adjusted by complex multiplication taking into account the value obtained by subtracting the estimation frequency error from the desired wave frequency error. And wherein the generating the first interference replica signal.

  In the receiver of the present invention, the desired wave signal processing means includes first subtracting means for subtracting the first interference wave replica signal from the IQ digital signal of the desired wave, and the IQ digital signal of the desired wave. A second subtracting means for subtracting the second interference wave replica signal; and a code on the transmission side with respect to the IQ digital signal of the desired wave obtained by subtracting each of the first interference wave replica signal and the second interference wave replica signal. Demodulating / decoding means for performing demodulation processing and decoding processing corresponding to the modulation / modulation method, and evaluation means for generating evaluation values for adjusting the amplitude and phase delay from the state of the demodulated signal after the demodulation processing; It is characterized by providing.

  Further, in the receiver according to the present invention, the control means may determine the amplitude and phase so that the demodulated signal state of the desired wave is closest to the normalized reference signal point of the corresponding modulation method according to the evaluation value. It is characterized by controlling delay adjustment.

  Furthermore, the satellite receiver of the present invention includes the polarization sharing converter of the present invention and the receiver of the present invention.

  Another aspect of the invention is a dual-polarization converter that converts a modulated wave signal in a radio frequency band of a digital signal transmitted using a plurality of types of polarization into a signal in an intermediate frequency band. Then, the modulated signal of the first polarization in the predetermined radio frequency band received via the satellite transmission path is converted into the intermediate frequency signal in the first band of the intermediate frequency band based on the local oscillation frequency signal of the first local oscillator. A first frequency converting means for converting the second modulated wave signal of the second polarized wave in the predetermined radio frequency band received via the satellite transmission line, to an intermediate frequency based on a local oscillation frequency signal of a second local oscillator A second frequency converting means for converting to an intermediate frequency signal of the second band of the band, and a third local oscillation frequency signal by using the local oscillation frequency signals of the first local oscillator and the second local oscillator, respectively. Generate and unmodulate wave Relative frequency conversion means for outputting as a relative intermediate frequency signal, a receiver for receiving the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal of the unmodulated wave via a predetermined cable And an output means for outputting the output toward the screen.

  According to another aspect of the receiver of the present invention, there is provided an intermediate frequency signal of the first band, an intermediate frequency signal of the second band, and an unmodulated wave output from the dual-polarization converter according to the present invention. A receiver that receives a relative intermediate frequency signal and is capable of removing an interference wave in one or both of the modulated wave signals of the first polarization and the second polarization, Based on the relative intermediate frequency signal of the unmodulated wave, the modulated wave is subjected to frequency conversion for either one of the modulated wave signal of the first polarization and the second polarized wave desired to be received. The intermediate frequency signal of the first band based on the first polarization, and the intermediate frequency signal of the second band based on the second polarization In the intermediate frequency signal A desired wave signal processing means for deriving a desired wave frequency error by carrier recovery, and a different polarization adjacent to the desired wave channel at a lower frequency. First interference wave replica signal generating means for processing an intermediate frequency signal of the channel of the different polarization for generating an interference wave of a different channel and generating a first interference wave replica signal as an IQ digital signal; The interfering wave due to the channel of the different polarization adjacent to the wave channel at the upper frequency is removed, and the intermediate frequency signal of the channel of the different polarization is signal-processed to generate the second interference wave replica signal as the IQ digital signal. Second interference wave replica signal generating means for performing a relative intermediate frequency of the modulated wave in a frequency band corresponding to the channel of the desired wave An IQ digital signal is generated based on several signals, and then used for estimation to estimate a relative frequency error between the local oscillation frequency signal of the first local oscillator and the local oscillation frequency signal of the second local oscillator by carrier recovery. A relative frequency error estimating means for deriving a frequency error, and the first interference wave replica signal and the second interference wave according to a change in the relative frequency error estimated from the desired wave frequency error and the estimation frequency error. And control means for controlling generation of the replica signal.

  According to another aspect of the present invention, there is provided a satellite receiver including the polarized wave converter and receiver according to another aspect of the present invention.

  According to the present invention, when cross polarization interference occurs in a desired wave, it is possible to suppress the required C / N deterioration for the desired wave in a highly accurate frequency-synchronized form.

  In particular, when cross polarization interference due to different polarization occurs in a desired wave having a high required C / N, the influence of interference due to cross polarization can be effectively suppressed by employing the satellite receiver according to the present invention. The reception performance can be improved.

It is a block diagram which shows schematic structure of the interference removal type | mold polarization shared converter of 1st Embodiment by this invention. It is a block diagram which shows schematic structure of the interference cancellation type | mold receiver of 1st Embodiment by this invention. (A) is a figure which shows the mode of the polarization interference of the spectrum of the right-handed circularly-polarized modulated wave signal input into an interference cancellation type | mold polarization | polarized-light shared converter, (B) It is a figure which shows the mode of the polarization interference of the spectrum of the modulation wave signal of the left-handed circular polarization input. It is a block diagram which shows schematic structure of the interference removal type | mold polarization shared converter of 2nd Embodiment by this invention. It is a block diagram which shows schematic structure of the interference cancellation type | mold receiver of 2nd Embodiment by this invention. It is a figure which shows schematic structure of a satellite broadcast system. It is a block diagram which shows schematic structure of the conventional generalized satellite receiver. (A) is the figure which illustrated the broadcast channel by the modulation wave signal of the left-handed and right-handed circularly polarized wave of 12 GHz band at the time of transmitting a digital signal using multiple kinds of polarization, (B) is each broadcast. It is the figure which illustrated the intermediate frequency signal (IF signal) corresponding to the modulated wave signal of a channel.

  Hereinafter, a satellite receiver 3 according to each embodiment of the present invention will be described with reference to the drawings. The satellite receiver 3 of each embodiment according to the present invention is configured to remove cross-polarized interference components when receiving a digital signal transmitted using a plurality of types of polarized waves.

[First Embodiment]
(Satellite receiver)
The satellite receiver 3 according to the first embodiment of the present invention includes a right-handed and a left-handed circularly polarized wave received via a polarization sharing receiving antenna (not shown) as disclosed in Non-Patent Document 1, for example. Interference-removing type polarization shared converter 31 that performs frequency conversion so that cross-polarization interference components can be removed from the modulated wave signal, and interference that performs demodulation and decoding so that cross-polarization interference components can be removed. A removal type receiver 32.

  FIG. 1 is a block diagram showing a schematic configuration of an interference cancellation type polarization shared converter 31 according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the interference cancellation type receiver 32 according to the first embodiment of the present invention. Note that the same reference numerals are given to the same components as those in the conventional configuration shown in FIG.

  The satellite receiver 3 of the present embodiment can be applied to the satellite broadcasting system shown in FIG. 6, and the right-handed and left-handed circularly polarized modulated wave signals transmitted from the satellite transmitter 1 based on the conventional technique are relayed to the satellite. This is a device for receiving via the device 2.

  Here, as described with reference to FIG. 7, the polarization sharing converter 31 based on the conventional technique converts the right-handed and left-handed circularly polarized waves into BS-IF bands having different frequencies, and then converts them into one coaxial line. For the purpose of enabling transmission by the cable 4, each of the right-handed frequency converter 311 and the left-handed frequency converter 312 is configured to have independent local oscillators 3114 and 3124, respectively.

  On the other hand, the interference cancellation type polarization shared converter 31 of the first embodiment according to the present invention will be described in detail later with reference to FIG. 1, but compared with the polarization shared converter of the conventional technique shown in FIG. The difference is that a relative frequency converter 313 is further provided, and the other configurations are the same. The relative frequency conversion unit 313 uses the output signals (local oscillation frequency signals) of the local oscillator 3114 of the right-handed frequency conversion unit 311 and the local oscillator 3124 of the left-handed frequency conversion unit 312, so that the local oscillators 3114 and 3124 Relative IF signal generated by generating a relative local oscillation frequency signal mixed so as to include a frequency error and performing a frequency conversion using the generated relative local oscillation frequency signal on the left-hand circularly polarized modulated wave signal of 12 GHz band Is generated and transmitted.

  The interference cancellation type receiver 32 according to the first embodiment of the present invention will be described in detail later with reference to FIG. 2, but compared with the conventional technique shown in FIG. For the purpose of removing the interference wave component superimposed on the IF signal, the desired wave signal processing unit 323, the first interference wave replica signal generation unit 321, the second interference wave replica signal generation unit 322, and the relative frequency error estimation unit 324 , And the point which is comprised so that the control part 325 may be provided.

(Interference cancellation type polarization shared converter)
First, with reference to FIG. 1, the interference cancellation type | mold polarization shared converter 31 of 1st Embodiment by this invention is demonstrated in detail.

  The interference-removal type polarization-polarized converter 31 of this embodiment uses a right-handed and left-handed circularly polarized wave received as a desired wave as a left-handed circularly-polarized modulated wave signal and received via a polarization-sharing receiving antenna (not shown). For generating a predetermined relative IF signal so that a cross-polarization (right-handed) interference component with respect to the desired wave can be removed on the interference cancellation type receiver 32 side It is.

  More specifically, the interference cancellation type polarization shared converter 31 shown in FIG. 1 is connected via a polarization shared reception antenna (not shown) to enable transmission to the interference cancellation type receiver 32 by the coaxial cable 4. A device that performs frequency conversion of received right-handed and left-handed circularly polarized modulated wave signals in the 12 GHz band into a BS-IF band for each polarization, and includes a right-handed frequency converter 311, a left-handed frequency converter 312, and A relative frequency conversion unit 313 is provided.

  As in the conventional technique shown in FIG. 7, the right-handed frequency conversion unit 311 receives the downlink right-handed circularly-polarized modulated wave signal from the satellite repeater 2, and a bandpass filter (BPF) 3111 An extraneous noise component is removed from the right-handed circularly polarized modulated wave signal in the 12 GHz band (11.7 to 12.75 GHz), and a right-handed circular shape based on the local oscillation frequency signal from the local oscillator 3114 by the mixer 3113. BS-IF of right-handed circular polarization obtained by frequency conversion to the BS-IF band of polarized waves (1032.23 to 2070.25 MHz) and removing unnecessary noise components other than the desired wave by a band-pass filter (BPF) 3112 An IF frequency intermediate frequency signal (desired right-handed IF signal) is generated.

  As in the conventional technique shown in FIG. 7, the left-handed frequency conversion unit 312 receives the downlink left-handed circularly-polarized modulated wave signal from the satellite repeater 2, and the 12 GHz band by the bandpass filter (BPF) 3121. The extraneous noise component is removed from the left-handed circularly polarized modulated wave signal (11.7 to 12.75 GHz), and the mixer 3123 uses the left-handed circularly polarized BS based on the local oscillation frequency signal from the local oscillator 3124. -Intermediate frequency of the left-handed circularly polarized BS-IF band obtained by converting the frequency to IF band (2224.41-3223.25 MHz) and removing extraneous noise components other than the desired wave by bandpass filter (BPF) 3112 A signal (desired left-handed IF signal) is generated.

  First, the relative frequency conversion unit 313 performs frequency conversion based on a frequency difference (frequency shift) on the local oscillation frequency signal of the local oscillator 3114 on the basis of the local oscillation frequency signal of the local oscillator 3124 by the mixer 3134 to obtain a bandpass filter ( BPF) 3131 generates a first frequency difference signal from which excess noise components have been removed from the frequency-converted band. Subsequently, the relative frequency conversion unit 313 first performs frequency conversion based on the frequency difference (frequency shift) on the local oscillation frequency signal of the local oscillator 3124 on the basis of the first frequency difference signal by the mixer 3135 to obtain a bandpass filter ( (BPF) 3132 generates a second frequency difference signal from which excess noise components are removed from the frequency-converted band. The second frequency difference signal becomes a relative local oscillation frequency signal mixed so as to include the frequency error of the local oscillators 3114 and 3124. Then, the relative frequency conversion unit 313 performs frequency difference based on the generated relative local oscillation frequency signal with respect to the 12 GHz band left-handed circularly polarized modulated wave signal obtained through the bandpass filter (BPF) 3121 by the mixer 3136. Frequency conversion by (frequency shift) is performed, and a bandpass filter (BPF) 3133 generates a relative IF signal from which extra noise components are removed from the band after the frequency conversion.

  The desired wave right-handed IF signal generated by the right-handed frequency converter 311, the desired wave left-handed IF signal generated by the left-handed frequency converter 312, and the relative IF signal generated by the relative frequency converter 313 are different from each other. As a result, there is no overlap due to the waves, and the interference cancellation type polarization shared converter 31 performs amplitude amplification (not shown) with substantially the same gain for each of the desired wave right-handed IF signal, desired wave left-handed IF signal, and relative IF signal. Are combined and transmitted to the interference cancellation type receiver 32 shown in FIG.

  Here, the input / output signals in the interference cancellation type polarization shared converter 31 will be described in more detail.

  The modulated wave signal in the 12 GHz band input to the interference cancellation type polarization shared converter 31 is arranged as shown in FIG. For example, by installing the interference-removing polarization-sharing converter 31 (or connecting via a distributor) to the dual-polarization receiving antenna (not shown) as disclosed in Non-Patent Document 1, the dual-polarization receiving antenna 12GHz band modulated wave signal (broadcast wave signal in this example) is separated into a right-handed circularly polarized wave and a left-handed circularly polarized wave signal by the interference-removing polarization dual-purpose converter 31 for signal processing. can do.

  The right-hand circularly polarized modulated wave signal is as shown in FIG. 3A. The right-handed circularly polarized wave as the main polarized wave is a desired wave, and the left-handed circularly polarized wave as a different polarized wave is an interference wave. The output interference wave is lower than the desired wave by a level corresponding to the cross polarization discrimination.

Here, in the desired wave of the right-handed circularly polarized modulated wave signal, the ideal center frequencies of (2n−1) ch and (2n + 1) ch are f _{(2n−1) R} and f _{(2n + 1) R} , respectively. To do. For example, in the case of BS-15ch and BS-17ch, the ideal center frequencies are f _{(2n-1) R} = 11.996 GHz and f _{(2n + 1) R} = 12.03436 GHz.

  In an actual satellite broadcasting system, as shown in FIG. 6, frequency conversion such as conversion to the uplink frequency (17 GHz band) from the satellite transmitter 1 or frequency conversion (17 GHz band to 12 GHz band) by the satellite repeater 2 is performed. Because of this, there is a unique frequency error for each channel.

For this reason, the frequency errors received before the input of the satellite receiver 3 in (2n-1) ch and (2n + 1) ch, which are desired waves of the right-handed circularly polarized modulated wave signal, are respectively Δf _{(2n-1 ) R} and Δf _{(2n + 1) R} , the actual center frequencies are f _{(2n−1) R} + Δf _{(2n−1) R} as shown in FIG.
f _{(2n + 1) R} + Δf _{(2n + 1) R}
It becomes.

The right-handed frequency conversion unit 311 shown in FIG. 1 converts the right-handed circularly polarized modulated wave signal into a BS-IF band using the local oscillator 3114 and the mixer 3113. At this time, an unmodulated wave signal or the like from the local oscillator 3114 that becomes an unnecessary wave component is suppressed by a bandpass filter (BPF) 3112. Assuming that the local oscillation frequency of the local oscillator 3114 is f ₁ and its error frequency is Δf ₁ , the frequencies after being converted into the BS-IF band by the right-handed frequency conversion unit 311 are (2n−1) ch and (2n + 1) ch. For each of
_{(F (2n-1) R} + Δf (2n-1) R) - (f 1 + Δf 1)
(F _{(2n + 1) R} + Δf _{(2n + 1) R} ) − (f ₁ + Δf ₁ )
It becomes.

  Similarly, the left-hand circularly polarized modulated wave signal is as shown in FIG. 3B. The left-handed circularly polarized wave, which is the main polarization, is the desired wave, and the right-handed circularly polarized wave, which is the different polarization, interferes. The interference wave is lower than the desired wave by the amount of cross polarization discrimination.

In the desired wave of the left-hand circularly polarized modulated wave signal, the ideal center frequency of (2n) ch is f _{(2n) L.}

As in the case of right-handed circular polarization, in an actual satellite broadcasting system, as shown in FIG. 6, conversion to the uplink frequency (17 GHz band) from the satellite transmitter 1 or frequency conversion at the satellite repeater 2 ( Since frequency conversion such as 17 GHz band to 12 GHz band) occurs, there is a unique frequency error for each channel. Therefore, in (2n) ch, which is the desired wave of the left-hand circularly polarized modulated wave signal, if the frequency error received before the input of the satellite receiver 3 is Δf _{(2n) L} , the actual center frequency is As shown in 3 (B),
f _{(2n) L} + Δf _{(2n) L}
It becomes.

The left-handed frequency conversion unit 312 shown in FIG. 1 performs frequency conversion of this left-handed circularly polarized modulated wave signal into the BS-IF band using the local oscillator 3124 and the mixer 3123. At this time, an unmodulated wave signal or the like from the local oscillator 3124 that becomes an unnecessary wave component is suppressed by a band pass filter (BPF) 3122. Assuming that the local oscillation frequency of the local oscillator 3124 is f ₂ and the error frequency thereof is Δf ₂ , the frequency after the conversion to the BS-IF band by the left-handed frequency conversion unit 312 is about (2n) ch.
(F _{(2n) L} + Δf _{(2n) L} ) − (f ₂ + Δf ₂ )
It becomes.

Next, the center frequency in the interference wave on the right-handed circularly polarized wave side and the left-handed circularly polarized wave side will be described. Before the input of the satellite receiver 3, the center frequencies of the interference wave (2n) ch on the right-handed circularly polarized wave side and the interference waves (2n-1) ch and (2n + 1) ch on the left-handed circularly polarized wave side are different. The same as the polarization side. That is, as shown in FIGS. 3A and 3B, f _{(2n) L} + Δf _{(2n) L} , respectively.
f _{(2n-1) R} + Δf _{(2n-1) R}
f _{(2n + 1) R} + Δf _{(2n + 1) R}
It becomes.

On the other hand, the interference wave (2n) ch on the right-handed circular polarization side passes through the right-handed frequency converter 311 and is subjected to frequency conversion, and the left-handed interference waves (2n-1) ch and (2n + 1) ch are left-handed. Since the frequency conversion is performed through the frequency conversion unit 312, the frequency converted into the BS-IF band is (f _{(2n) L} + Δf _{(2n) L} ) − (f ₁ + Δf ₁ ), respectively.
(F _{(2n-1) R} + Δf _{(2n-1) R} )-(f ₂ + Δf ₂ )
(F _{(2n + 1) R} + Δf _{(2n + 1) R} ) − (f ₂ + Δf ₂ )
It becomes.

The example shown in FIG. 1 shows an example for the purpose of removing the interference wave on the left-handed circularly polarized wave side. In order to subtract the left-handed circularly polarized wave-like interference wave from the desired wave on the right-handed circularly polarized wave side. Needs to grasp − (f ₂ + Δf ₂ ) + (f ₁ + Δf ₁ ) as the relative frequency. Since f ₁ and f ₂ are fixed values, −Δf ₂ + Δf ₁ may be known as a relative frequency.

  In view of this, the interference removal type polarization shared converter 31 of this embodiment includes a relative frequency conversion unit 313 as shown in FIG. 1 for the purpose of grasping the relative frequency. The relative frequency conversion unit 313 does not provide a new local oscillator, generates a relative local oscillation frequency signal having a different frequency from the difference between the output signals of the local oscillator 3114 and the local oscillator 3124, and produces a 12 GHz band left-handed circularly polarized modulated wave. The signal is subjected to frequency conversion using the generated relative local oscillation frequency signal, and a relative IF signal is generated and transmitted to the interference cancellation type receiver 32.

The local oscillation frequency signals (f ₁ + Δf ₁ ) and (f ₂ + Δf ₂ ) output from the local oscillator 3114 and the local oscillator 3124 are input to the mixer 3134 in the relative frequency conversion unit 313, respectively, and a frequency difference (frequency shift). After that, the first frequency difference signal is generated by removing the excess noise component from the band after the frequency conversion by the band pass filter (BPF) 3131. The frequency of the first frequency difference signal after passing through the BPF 3131 is
(F ₁ + Δf ₁ ) − (f ₂ + Δf ₂ )
It becomes.

Subsequently, the first frequency difference signal after passing through the BPF 3131 and the local oscillation frequency signal of the local oscillator 3124 are input to the mixer 3135, subjected to frequency conversion by the frequency difference (frequency shift), and then a bandpass filter (BPF) ) 3132 generates a second frequency difference signal from which an excess noise component is removed from the frequency-converted band. The frequency of the second frequency difference signal after passing through the BPF 3132 is
{F ₂ − (f ₁ −f ₂ )} + {Δf ₂ − (Δf ₁ −Δf ₂ )}
It becomes.

here,
f ₃ = f ₂ − (f ₁ −f ₂ )
Δf ₃ = Δf ₂ − (Δf ₁ −Δf ₂ )
, The frequency of the second frequency difference signal after passing through the BPF 3132 is
f ₃ + Δf ₃
It becomes.

The second frequency difference signal becomes a relative local oscillation frequency signal mixed so as to include the frequency error of the local oscillators 3114 and 3124. The relative local oscillation frequency signal f ₃ + Δf ₃ and the left-hand circularly polarized modulated wave signal after passing through the BPF 3121 are input to the mixer 3136, and the generated relative relative to the 12 GHz-band left-hand circularly polarized modulated wave signal is input. Frequency conversion by frequency difference (frequency shift) is performed based on the local oscillation frequency signal. Thereafter, a band-pass filter (BPF) 3133 generates a relative IF signal from which excess noise components have been removed from the frequency-converted band. The center frequency of the relative IF signal after passing through BPF 3133 is
_{(F (2n) L + Δf} (2n) L) - (f 3 + Δf 3)
It becomes.

Therefore, in the outputs of the left rotation frequency conversion unit 312 and the relative frequency conversion unit 313 shown in FIG. 1, the center frequencies of the desired wave left rotation IF signal and the relative IF signal are respectively (f _{(2n) L} + Δf _{(2n) L} )-(F ₂ + Δf ₂ )
_{(F (2n) L + Δf} (2n) L) - (f 3 + Δf 3)
And each error frequency is
Δf _{(2n) L} −Δf ₂
Δf _{(2n) L} −Δf ₃
It becomes.

  These desired wave right-handed IF signal, desired wave left-handed IF signal, and relative IF signal are transmitted from the interference removal type polarization shared converter 31 to the interference removal type receiver 32, and will be described below. By the processing of the receiver 32, the interference wave right-handed IF signal superimposed on the desired wave left-handed IF signal is removed.

(Interference canceling receiver)
Next, the interference cancellation receiver 32 according to the first embodiment of the present invention will be described in detail with reference to FIG. The interference cancellation type receiver 32 includes a first interference wave replica signal generation unit 321, a second interference wave replica signal generation unit 322, a desired wave signal processing unit 323, a relative frequency error estimation unit 324, and a control unit 325.

  The first interference wave replica signal generation unit 321 is a functional unit that generates a low-frequency side replica signal of the interference wave right-handed IF signal superimposed on the desired wave left-handed IF signal, and selects a channel (2n−1). A BPF 3211, an analog / digital (A / D) converter 3212, a complex multiplier 3214, a first NCO (numerically controlled oscillator) 3215, and an amplitude delay adjuster 3216.

  The BPF 3211 receives a combined signal transmitted from the interference cancellation type polarization shared converter 31 via the coaxial cable 4 and a channel (2n−1) immediately below the desired (2n) ch selected by the user. Is automatically selected and filtered to extract the desired wave right-handed IF signal (2n-1) ch and output it to the A / D converter 3212. Thus, the first interference wave replica signal generation unit 321 becomes a signal processing system that substantially inputs and processes the desired wave right-handed IF signal (2n−1) ch. Here, the setting of the desired (2n) ch selected by the user and the channel (2n-1) immediately below it is controlled by the control unit 325.

  The A / D converter 3212 digitizes (quantizes) the desired wave right-handed IF signal (2n-1) ch, which is an analog signal, based on the sampling clock (CLK), generates an IQ digital signal, and generates a complex multiplier. It outputs to 3214. Here, the sampling clock (CLK) corresponds to a frequency based on the symbol rate of the desired wave right-handed IF signal (2n−1) ch, and is controlled by the control unit 325.

  The complex multiplication unit 3214 multiplies the IQ digital signal by the relative frequency error signal generated by the first NCO 3215, and the desired wave right-handed IF signal (frequency synchronization with respect to the desired wave left-handed IF signal (2n) ch) ( 2n-1) ch is output to the amplitude delay adjustment unit 3216.

The first NCO 3215 inputs a desired wave frequency error C ₂ obtained from the desired wave signal processing unit 323, a frequency error C ₃ obtained from the relative frequency error estimation unit 324, and a frequency signal having a specified value of −19.18 MHz, and the channel A relative frequency error signal in which a relative frequency error (−Δf ₂ + Δf ₁ ) is added based on a negative frequency (−19.18 MHz) corresponding to a half value of the interval is generated and supplied to the complex multiplier 3214.

  The amplitude delay adjustment unit 3216 right-angles the desired wave after complex multiplication so that the amplitude and phase level correspond to the interference wave (interference wave right-handed IF signal (2n-1) ch) superimposed on the desired wave left-handed IF signal. A first interference wave replica signal is generated by adjusting the amplitude and phase delay of the rotation IF signal (2n−1) ch, and is output to the first subtraction unit 3234 in the desired wave signal processing unit 3237. The amplitude delay adjustment by the amplitude delay adjustment unit 3216 is performed by the control unit 325 so that the EVM value is minimized based on the evaluation result (EVM value) of the EVM (Error Vector Modulation) 3237 in the desired wave signal processing unit 323. Be controlled.

  The second interference wave replica signal generation unit 322 is a functional unit that generates a high-frequency side replica signal of the interference wave right-handed IF signal superimposed on the desired wave left-handed IF signal, and is used to select a channel (2n + 1). A BPF 3221, an analog / digital (A / D) converter 3222, a complex multiplier 3224, a second NCO (numerically controlled oscillator) 3225, and an amplitude delay adjuster 3226 are provided.

  The BPF 3221 receives a composite signal transmitted from the interference cancellation type polarization shared converter 31 via the coaxial cable 4, and automatically selects the nearest upper channel (2n + 1) for the desired (2n) ch selected by the user. By selecting and filtering, the desired wave right-handed IF signal (2n + 1) ch is extracted and output to the A / D converter 3222. Thereby, the second interference wave replica signal generation unit 322 becomes a signal processing system that substantially inputs and processes the desired wave clockwise IF signal (2n + 1) ch. Here, the setting of the desired (2n) ch selected by the user and the channel (2n + 1) immediately above it is controlled by the control unit 325.

  The A / D converter 3222 digitizes (quantizes) the desired wave right-handed IF signal (2n + 1) ch, which is an analog signal, based on the sampling clock (CLK), generates an IQ digital signal, and supplies the IQ signal to the complex multiplier 3224. Output. Here, the sampling clock (CLK) corresponds to a frequency based on the symbol rate of the desired wave clockwise IF signal (2n + 1) ch, and is controlled by the control unit 325.

  The complex multiplication unit 3224 multiplies the IQ digital signal by the relative frequency error signal generated by the second NCO 3225, and the desired wave right-handed IF signal (frequency synchronized with the desired wave left-handed IF signal (2n) ch) ( 2n + 1) ch is output to the amplitude delay adjustment unit 3226.

The second NCO 3225 receives the desired wave frequency error C ₂ obtained from the desired wave signal processing unit 323, the frequency error C ₃ obtained from the relative frequency error estimation unit 324, and the frequency signal of the specified value + 19.18 MHz, and the channel interval A relative frequency error signal that takes into account the relative frequency error (−Δf ₂ + Δf ₁ ) with reference to a plus frequency (+19.18 MHz) corresponding to the half value of is generated and supplied to the complex multiplier 3224.

  The amplitude delay adjustment unit 3226 selects the desired wave right-handed IF after complex multiplication so that the amplitude and phase level correspond to the interference wave (interference wave right-handed IF signal (2n + 1) ch) superimposed on the desired wave left-handed IF signal. A second interference wave replica signal is generated by adjusting the amplitude and phase delay of the signal (2n + 1) ch, and is output to the second subtraction unit 3235 in the desired wave signal processing unit 3237. The amplitude delay adjustment by the amplitude delay adjustment unit 3226 is controlled by the control unit 325 so that the EVM value is minimized based on the evaluation result (EVM value) of the EVM 3237 in the desired wave signal processing unit 323.

  The desired wave signal processing unit 323 is a functional unit for demodulating / decoding the desired left-handed IF signal while removing superimposed interference waves, and includes a BPF 3231 for selecting a channel (2n), analog / digital (A / D) A conversion unit 3232, a demodulation unit 3233, a first subtraction unit 3234, a second subtraction unit 3235, a decoding unit 3236, and an EVM 3237 are provided.

  The BPF 3231 receives a composite signal transmitted from the interference cancellation type polarization shared converter 31 via the coaxial cable 4, selects a desired (2n) ch selected by the user, and filters the desired signal to the left. The IF signal (2n) ch is extracted and output to the A / D converter 3232. Accordingly, the desired wave signal processing unit 323 becomes a signal processing system that inputs and processes the desired wave left-handed IF signal (2n) ch on which the interference wave right-handed IF signal is superimposed.

  The A / D conversion unit 3232 digitizes (quantizes) the desired wave left-handed IF signal (2n) ch, which is an analog signal, based on the sampling clock (CLK), generates an IQ digital signal, and sends it to the first subtraction unit 3234. Output. Here, the sampling clock (CLK) corresponds to a frequency based on the symbol rate of the desired wave left-handed IF signal (2n) ch and is controlled by the control unit 325.

  The first subtraction unit 3234 receives the IQ digital signal output from the A / D conversion unit 3232 and also receives the first interference wave replica signal output from the amplitude delay adjustment unit 3216. The first interference wave replica signal is subtracted and output to the second subtraction unit 3235. Thus, the lower frequency interference wave component (interference wave right-handed IF signal (2n) generated based on the desired wave right-handed IF signal of the channel (2n-1) immediately below the desired wave left-handed IF signal (2n) ch. -1) ch) is removed from the IQ digital signal of the desired wave left-hand IF signal (2n) ch.

  The second subtracting unit 3235 receives the IQ digital signal output from the first subtracting unit 3234, and also receives the second interference wave replica signal output from the amplitude delay adjusting unit 3226, and receives the second digital signal from the IQ digital signal. The two interference wave replica signals are subtracted and output to the demodulator 3233. As a result, the interference wave component of the upper frequency (interference wave right-handed IF signal (2n + 1) ch) generated based on the desired wave right-handed IF signal of the channel (2n + 1) immediately above the desired wave left-handed IF signal (2n) ch. Are removed from the IQ digital signal of the desired wave left-handed IF signal (2n) ch.

  Of course, the arrangement order of the first subtraction unit 3234 and the second subtraction unit 3235 may be reversed.

  The demodulation unit 3233 performs demodulation processing corresponding to the modulation processing by the satellite transmission apparatus 1 on the IQ digital signal obtained through the first subtraction unit 3234 and the second subtraction unit 3235 and outputs the result to the decoding unit 3236.

Although not shown, the demodulation unit 3233 is provided with a complex multiplier, an automatic gain adjuster, a waveform equalizer, and the like, as well as a symbol reproduction unit 32331 and a carrier reproduction unit 32332. The symbol reproducing unit 32331 reproduces symbols in order to acquire symbol synchronization for the quantized IQ digital signal, and controls to detect and correct a phase error with respect to the sampling clock (CLK). The carrier recovery unit 32332 is a numerically controlled oscillator (NCO) (not shown) for carrier recovery that is used when the IQ digital signal is subjected to complex multiplier processing and waveform equalization from the received phase rotation amount at the signal point position of the synchronization symbol. The desired wave frequency error C ₂ is controlled to be detected and corrected, and the desired wave frequency error C ₂ is output to the first NCO 3215 and the second NCO 3225.

In addition, the desired wave frequency error _{C 2} is,
Δf _{(2n) L} −Δf ₂ = C ₂
It can be expressed as.

  The decoding unit 3236 performs a decoding process corresponding to the error correction coding process by the satellite transmission apparatus 1 on the IQ digital signal demodulated by the demodulation unit 3233, and outputs the result as an output signal to an external receiver (not shown).

  The output of the demodulation unit 3233 is evaluated by the EVM 3237, and the control unit 325 adjusts the amplitude values of the amplitude delay adjustments 3216 and 3226 and the delay amount thereof so that the EVM value as the evaluation result is minimized.

The relative frequency error estimation unit 324 is a functional unit for deriving a frequency error C ₃ used for estimation of the relative frequency error (−Δf ₂ + Δf ₁ ) of the local oscillators 3114 and 3124 in the interference cancellation type polarization shared converter 31. A BPF 3241 for selecting a channel (2n), an A / D converter 3242, and a demodulator 3243 are provided.

  The BPF 3241 receives the combined signal transmitted from the interference cancellation type polarization shared converter 31 via the coaxial cable 4, and selects the frequency band of the relative IF signal corresponding to the desired (2n) ch selected by the user. By filtering, the relative IF signal (2n) ch is extracted and output to the A / D converter 3242. Thereby, the relative frequency error estimation unit 323 becomes a signal processing system that substantially receives and processes the relative IF signal (2n) ch.

  The A / D conversion unit 3242 digitizes (quantizes) the relative IF signal (2n) ch that is an analog signal based on the sampling clock (CLK), generates an IQ digital signal, and outputs the IQ signal to the demodulation unit 3243. Here, the sampling clock (CLK) corresponds to a frequency based on the symbol rate of the relative IF signal (2n) ch, and is controlled by the control unit 325.

Demodulator 3243 performs demodulation processing corresponding to the modulation processing by the satellite transmission device 1 for IQ digital signal obtained through the A / D converter 3242, and outputs to the 1NCO3215 and second 2NCO3225 derive the frequency error _{C 3} .

Although not shown, the demodulation unit 3243 is provided with a complex multiplier, an automatic gain adjuster, a waveform equalizer, and the like, as well as a symbol reproduction unit 32431 and a carrier reproduction unit 32432. The symbol reproduction unit 32431 reproduces symbols in order to acquire symbol synchronization for the quantized IQ digital signal, and controls to detect and correct a phase error with respect to the sampling clock (CLK). The carrier regeneration unit 32432 is a numerically controlled oscillator (NCO) (not shown) for carrier regeneration that is used when the IQ digital signal is subjected to complex multiplier processing and waveform equalization from the received phase rotation amount at the signal point position of the synchronization symbol. The frequency error C ₃ is controlled to be detected and corrected, and the frequency error C ₃ is output to the first NCO 3215 and the second NCO 3225.

The frequency error _{C 3} is,
Δf _{(2n) L} −Δf ₃ = C ₃
It can be expressed as.

Here, the relative frequency error signal in consideration of the relative frequency error (−Δf ₂ + Δf ₁ ) between the local oscillators 3114 and 3124 in the interference cancellation type polarization shared converter 31 will be described.

Since Δf ₃ = Δf ₂ − (Δf ₁ −Δf ₂ ),
Δf _{(2n) L} −2Δf ₂ + Δf ₁ = C ₃
Can be calculated.

Then, the relative frequency error is such that the signal is synchronized with the desired wave counterclockwise IF signal (2n) ch from Δf _{(2n) L} −Δf ₂ = C ₂ .
−Δf ₂ + Δf ₁ = C ₃ −C ₂
Can be derived.

Therefore, by inputting C ₃ -C ₂ to the first NCO 3215 and the second NCO 3225, the interference wave right-handed IF signal (2n-1) ch and the interference wave right-handed IF signal superimposed on the desired wave left-handed IF signal (2n) ch. (2n + 1) ch can be subtracted in a frequency-synchronized form.

The control unit 325 is synchronized with the first interference wave replica signal generation unit 321, the second interference wave replica signal generation unit 322, the desired wave signal processing unit 323, and the relative frequency error estimation unit 324 as the satellite receiver 3. Control in the form of In addition, the control unit 325 performs interlock control to input to the first NCO 3215 and the second NCO 3225 according to changes in the values of the frequency errors C ₃ and C ₂ obtained from the demodulation units 3233 and 3243, respectively. In addition, the control unit 325 controls the amplitude delay adjustments 3216 and 3226 so that the EVM value of the EVM 3237 is minimized (closest to the normalized reference signal point of the corresponding modulation method in the desired wave to be processed). To do.

  According to the satellite receiver 3 of the present embodiment including the interference cancellation type polarization shared converter 31 and the interference cancellation type receiver 32 configured as described above, the relative frequency conversion unit 313 and the relative frequency error estimation unit 324 It is possible to suppress the interference wave with respect to the desired wave in a highly accurate frequency-synchronized form.

  Further, for example, in a digital signal transmitted by sharing a 16 APSK left-hand circularly polarized wave with an 8PSK right-hand circularly polarized wave, the 16 APSK left-hand circularly polarized wave is an 8PSK right-hand circularly polarized wave. When the required C / N is higher than the modulated wave signal of the wave, even if cross polarization interference due to different polarization occurs in the desired wave having a high required C / N, the interference wave component is accurately obtained. It can be removed. For this reason, it is possible to suppress the required C / N deterioration for the desired wave. Therefore, by employing the satellite receiver 3, it is possible to effectively suppress the influence of interference due to cross polarization and improve the reception performance.

  In the example of the first embodiment described above, an example in which a left-hand circularly polarized modulated wave signal is a desired wave and an interference wave due to a right-hand circularly polarized modulated wave signal is removed as an object is described. Also good. That is, the satellite receiver 3 according to the first embodiment can be applied to a use in which a right-hand circularly polarized modulated wave signal is a desired wave and an interference wave by a left-hand circularly polarized modulated wave signal is removed as a target. .

  In order to configure the satellite receiver 3 so that both the left-handed and right-handed circularly-polarized modulated wave signals are set as desired waves, and both polarized-wave modulated wave signals are simultaneously received and simultaneously output. Interference cancellation type polarization shared converter 31 in which the components of interference cancellation type polarization shared converter 31 and the components of interference cancellation type receiver 32 are arranged in parallel in satellite receiver 3 of the embodiment, and interference cancellation type reception The machine 32 can also be configured.

  In addition, for example, as described below, a configuration in which one of left-handed and right-handed circularly polarized wave signals can be selected as a desired wave can be employed. Hereinafter, the satellite receiver 3 of the second embodiment will be described with reference to FIGS. 4 and 5.

[Second Embodiment]
(Satellite receiver)
The satellite receiver 3 according to the second embodiment of the present invention has a right-handed and a left-handed circularly polarized wave received via a polarization sharing receiving antenna (not shown) as disclosed in Non-Patent Document 1, for example. An interference-removing polarization-sharing converter 31 that performs frequency conversion so that one of the modulated wave signals can be selected as a desired wave and the interference component of cross-polarized waves can be removed. And an interference cancellation type receiver 32 that performs demodulation and decoding so that the interference component of the wave can be removed.

  FIG. 4 is a block diagram showing a schematic configuration of the interference cancellation type polarization-shared converter 31 according to the second embodiment of the present invention. FIG. 5 is a block diagram showing a schematic configuration of the interference cancellation type receiver 32 according to the second embodiment of the present invention. Note that the same reference numerals are assigned to the same components as those of the first embodiment shown in FIGS. 1 and 2.

(Interference cancellation type polarization shared converter)
First, with reference to FIG. 4, the interference cancellation type polarization shared converter 31 according to the second embodiment of the present invention will be described in detail.

  Similar to the first embodiment, the interference-removal polarization-division converter 31 of the second embodiment includes a right-handed frequency converter 311, a left-handed frequency converter 312, and a relative frequency converter 313. In addition, the configurations of the right-handed frequency converter 311 and the left-handed frequency converter 312 in the second embodiment are substantially the same as those in the first embodiment, and the relative frequency converter 313 in the second embodiment includes switches 3137, 3138, 3139 is further provided, and the switches 3137, 3138, and 3139 are controlled based on the selection signal from the interference cancellation type receiver 32, but other components are different. It is the same. For this reason, the matter regarding these differences is mainly demonstrated.

  The switch 3137 receives the interference cancellation type reception so that one of the output of the BPF 3111 in the right-handed frequency converter 311 and the output of the BPF 3121 in the left-handed frequency converter 312 is input to the mixer 3136 in the relative frequency converter 313 as a desired wave. Switching control is performed based on a selection signal from the machine 32.

  The switch 3138 is an interference cancellation type so that either one of the output of the local oscillator 3114 in the right-handed frequency converter 311 and the output of the local oscillator 3124 in the left-handed frequency converter 312 is input to the mixer 3134 in the relative frequency converter 313. Switching control is performed based on a selection signal from the receiver 32.

  The switch 3139 is an interference elimination type so that one of the output of the local oscillator 3114 in the right-handed frequency converter 311 and the output of the local oscillator 3124 in the left-handed frequency converter 312 is input to the mixer 3135 in the relative frequency converter 313. Switching control is performed based on a selection signal from the receiver 32.

When the selection signal selects that the output of the BPF 3121 is input to the mixer 3136 as a desired wave by the switch 3137, the switch 3138 controls the input of the local oscillator 3114 to the mixer 3134, and the switch 3139 controls the local oscillator 3124. Are controlled to be input to the mixer 3135. In this case, the operation is the same as in the first embodiment. That is, the relative IF signal is (f _{(2n) L} + Δf _{(2n) L} ) − (f ₃ + Δf ₃ ), and at this time, f ₃ + Δf ₃ = {f ₂ − (f ₁ −f ₂ )} − { Δf ₂ − (Δf ₁ −Δf ₂ )}

On the other hand, when the selection signal selects that the output of the BPF 3111 is input to the mixer 3136 as the desired wave by the switch 3137, the switch 3138 controls the input of the output of the local oscillator 31214 to the mixer 3134 and the switch 3139 controls the local signal. Control is performed so that the output of the oscillator 3114 is input to the mixer 3135. In this case, the first embodiment is an operation in which the relationship between the desired wave and the interference wave is reversed. That is, the relative IF signal is (f _{(2n−1) L} + Δf _{(2n−1) L} ) − (f ₃ + Δf ₃ ) or (f _{(2n + 1) L} + Δf _{(2n + 1) L} ) − (f ₃ + Δf _3). At this time, f ₃ + Δf ₃ = {f ₁ − (f ₂ −f ₁ )} − {Δf ₁ − (Δf ₂ −Δf ₁ )}.

(Interference canceling receiver)
Next, the interference cancellation type receiver 32 according to the second embodiment of the present invention will be described in detail with reference to FIG. As in the first embodiment, the interference cancellation type receiver 32 of the second embodiment includes a first interference wave replica signal generation unit 321, a second interference wave replica signal generation unit 322, a desired wave signal processing unit 323, a relative frequency. An error estimation unit 324 and a control unit 325 are provided.

  In the second embodiment, when the control unit 325 selects a desired channel selected by the user as a desired wave, the interference-removal polarization-polarized converter 31 so that the polarization corresponding to the selection is the desired wave. However, it is different in that it is configured to output a selection signal. This selection signal is a signal in a frequency band that does not affect the combined signal transmitted from the interference-removing polarization-sharing converter 31 through the coaxial cable 4.

  As in the first embodiment, when the user selects a desired channel in either the left-handed or right-handed circularly-polarized modulation signal, the control unit 325 selects the desired wave signal processing unit 323 for the selection. The first interference wave replica signal generation unit 321 and the second interference wave replica are controlled so as to input and process the IF signal of the polarization corresponding to the desired wave as the first polarization IF signal, and to remove the interference wave component. The signal generator 322 and the relative frequency error estimator 324 are controlled.

  Thereby, it can be set as the structure which can be selected so that either one of the left-handed and right-handed circularly polarized wave may be a desired wave. According to the second embodiment configured as described above, regardless of whether or not the required wave has a high required C / N, the frequency synchronization can be achieved with high accuracy according to the channel selected by the user. It becomes possible to remove the interference wave component with respect to the desired wave. As a result, it is possible to suppress the required C / N deterioration for the desired wave.

  In each of the above-described embodiments, when a relative IF signal is generated by the relative frequency conversion unit 313 and transmitted to the interference cancellation type receiver 32 via the coaxial cable 4, a coaxial booster (see FIG. (Not shown) is installed. In other words, in the interference cancellation type polarization shared converter 31 shown in FIG. 1 (or FIG. 4), the right-handed and left-handed circularly-polarized modulated wave signal (desired wave) and the relative IF signal are respectively amplified by predetermined power by a coaxial booster. Then, the data is multiplexed and transmitted by the coaxial cable 4.

  At this time, in the example of each embodiment described above, the relative IF signal generated by the relative frequency conversion unit 313 is formed as a modulated wave corresponding to the desired wave, and is amplified by the coaxial booster and multiplexed and transmitted. Become.

(Modification)
As a modified example, the relative IF signal output from the relative frequency conversion unit 313 is a non-modulated wave (CW) generated based only on the local oscillation frequency signals from the local oscillators 3114 and 3124, and is passed through the coaxial booster. A multiplex transmission configuration may also be used. That is, in the relative frequency conversion unit 313 shown in FIG. 1 (or FIG. 4), the output of the bandpass filter (BPF) 3131 is converted into a non-modulated wave relative IF signal (“f ₃ + Δf ₃ −f ₂ −Δf ₁ ” As a modulated wave signal), the signal is multiplexed and transmitted by the coaxial cable 4 through the coaxial booster. By configuring the relative IF signal as an unmodulated wave in this way, it is possible to reduce the influence of interference caused by the relative IF signal in the coaxial booster.

In this case, the interference cancellation type receiver 32 shown in FIG. 2 (or FIG. 5) reproduces the relative IF signal of the modulated wave corresponding to the desired wave based on the relative IF signal of the unmodulated wave. . More specifically, in the interference cancellation type receiver 32, the non-interval is provided before the band pass filter (BPF) 3241 in the relative frequency error estimation unit 324 in the interference cancellation type receiver 32 shown in FIG. 2 (or FIG. 5). Based on the relative IF signal of the modulated wave, one of the right-handed circularly polarized wave and the left-handed circularly polarized wave obtained from the coaxial cable 4 desired to be received (for example, a bandpass filter) (Output of (BPF) 3231) is extracted and frequency conversion is performed, and frequency conversion means for reproducing a relative IF signal of a modulated wave (a signal of “f _{(2n) L} + Δf _{(2n) L−} (f ₃ + Δf ₃ )”) Is provided.

  This frequency conversion means is configured to input the reproduced relative IF signal of the modulated wave to a bandpass filter (BPF) 3241.

  Then, after the relative IF signal of the modulated wave is input to the bandpass filter (BPF) 3241, the same processing as in the first or second embodiment is performed.

  Even in such a configuration, when cross-polarization interference occurs in the desired wave, it is possible to suppress the required C / N deterioration with respect to the desired wave with high accuracy in frequency synchronization.

  In particular, when cross polarization interference due to different polarization occurs in a desired wave having a high required C / N, the influence of interference due to cross polarization can be effectively suppressed by employing the satellite receiver according to the present invention. The reception performance can be improved.

  Although specific embodiments and modifications have been described above, the present invention should not be construed as being limited by the examples and modifications of the above-described embodiments, and is limited only by the claims. For example, right-handed and left-handed circularly polarized waves have been described as examples, but the present invention can also be applied to a mode using horizontal polarization and vertical polarization. Further, the present invention can also be applied to an aspect using a right-slanted 45 ° polarized wave and a left-slanted 45 ° polarized wave.

  In the description of the above-described embodiment, an example in which two interference wave component replica signals are generated for two types of polarization has been described. However, one or more interference wave component replica signals may be generated. Can do.

  In the description of the above-described embodiment, the example in which the amplitude and the phase delay related to the generation of the interference wave replica signal are adjusted based on the evaluation result based on the EVM (Error Vector Modulation) has been described. Based on the evaluation result based on MER (Modulation Error Ratio), it is also possible to adjust the amplitude and phase delay related to the generation of the interference wave replica signal.

  According to the present invention, when cross polarization interference occurs in a desired wave, for example, when a desired wave having a high required C / N is received, it is possible to suppress the required C / N degradation for the desired wave. This is useful for removing cross-polarized interference components related to reception of modulated wave signals using a plurality of polarized waves.

DESCRIPTION OF SYMBOLS 1 Satellite transmitter 2 Satellite repeater 3 Satellite receiver 31 Interference cancellation type | mold polarization shared converter, polarization shared converter 311 Right-handed frequency conversion part 3111, 3112 Band pass filter (BPF)
3113 Mixer 3114 Local oscillator 312 Left-handed frequency converter 3121, 3122 Band pass filter (BPF)
3123 Mixer 3124 Local oscillator 313 Relative frequency converter 3131, 3132, 3133 Band pass filter (BPF)
3134, 3135, 3136 Mixer 32 Interference cancellation type receiver, receiver 321 First interference wave replica signal generation unit 3211 Band pass filter (BPF)
3212 Analog / Digital (A / D) Converter 3214 Complex Multiplier 3215 First NCO
3216 Amplitude delay adjustment unit 322 Second interference wave replica signal generation unit 3221 Band pass filter (BPF)
3222 Analog-to-digital (A / D) converter 3224 Complex multiplier 3225 2nd NCO
3226 Amplitude delay adjustment unit 323 Desired wave signal processing unit 3231 Band pass filter (BPF)
3232 Analog to digital (A / D) conversion unit 3233 Demodulation unit 32331 Symbol reproduction unit 32332 Carrier reproduction unit 3234 First subtraction unit 3235 Second subtraction unit 3236 Decoding unit 3237 EVM
324 Relative Frequency Error Estimator 3241 Bandpass Filter (BPF)
3242 Analog / digital (A / D) conversion unit 3243 demodulation unit 32431 symbol reproduction unit 32432 carrier reproduction unit 325 control unit

Claims (13)

A polarization sharing converter that converts a modulated wave signal in a radio frequency band of a digital signal transmitted using a plurality of types of polarization into a signal in an intermediate frequency band,
A modulated wave signal of a first polarization in a predetermined radio frequency band received via a satellite transmission path is converted into an intermediate frequency signal in a first band of an intermediate frequency band based on a local oscillation frequency signal of a first local oscillator. First frequency conversion means;
The modulated signal of the second polarized wave in the predetermined radio frequency band received via the satellite transmission path is converted into an intermediate frequency signal in the second band of the intermediate frequency band based on the local oscillation frequency signal of the second local oscillator. Second frequency converting means for converting;
A third local oscillation frequency signal is generated using the local oscillation frequency signals of the first local oscillator and the second local oscillator, and the modulated wave signals of the first polarization and the second polarization are Relative frequency conversion means for generating a relative intermediate frequency signal by frequency-converting one of the modulation wave signals based on the third local oscillation frequency signal;
An output means for outputting the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal toward a receiver via a predetermined cable;
A dual-polarized converter comprising:   The dual-polarized converter according to claim 1, wherein the digital signal is transmitted as a broadcast wave using a plurality of types of polarized waves. The predetermined cable comprises a coaxial cable;
The output means synthesizes the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal, and outputs the synthesized signal to the receiver via the coaxial cable. The polarization sharing converter according to claim 1 or 2.   The modulation wave signal having a higher required C / N ratio among the modulation signals of the first polarization and the second polarization is configured to be an object to remove interference waves due to different polarizations. The polarization sharing converter according to any one of claims 1 to 3.   Of the modulated wave signals of the first polarization and the second polarized wave, the modulated wave signal selected by the selection signal from the receiver is configured to be an object to remove interference waves due to different polarizations. The polarization sharing converter according to any one of claims 1 to 3, wherein the converter is a polarization sharing converter. Receiving the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal output from the dual-polarization converter according to any one of claims 1 to 5, A receiver capable of removing an interference wave in one or both of the modulated wave signals of the first polarization and the second polarized wave,
The channel in the intermediate frequency signal in any one of the first frequency band based on the first polarization and the second frequency band based on the second polarization is set as a desired wave. A desired wave signal processing means for generating an IQ digital signal by signal processing and deriving a desired wave frequency error by carrier reproduction;
A first interference wave replica is processed as an IQ digital signal by processing an intermediate frequency signal of the channel of the different polarization with an interference wave of the channel of the different polarization adjacent to the channel of the desired wave as a target to be removed. First interference wave replica signal generation means for generating a signal;
The intermediate frequency signal of the differently polarized channel is signal-processed to remove the interference wave from the differently polarized channel adjacent to the desired wave channel at the upper frequency, and the second interference wave replica signal as an IQ digital signal is processed. Second interference wave replica signal generating means for generating
After generating as an IQ digital signal based on the relative intermediate frequency signal in the frequency band corresponding to the channel of the desired wave, a local oscillation frequency signal of the first local oscillator and a local part of the second local oscillator are generated by carrier recovery. A relative frequency error estimating means for deriving an estimation frequency error for estimating the relative frequency error of the oscillation frequency signal;
Control means for controlling generation of the first interference wave replica signal and the second interference wave replica signal in accordance with a change in the relative frequency error estimated from the desired wave frequency error and the estimation frequency error;
A receiver comprising: The first interference wave replica signal generating means uses a negative frequency corresponding to a half value of a channel interval as a reference for an IQ digital signal of an intermediate frequency signal of a different polarization channel adjacent to the desired wave channel at a lower frequency. A complex multiplication taking into account the value obtained by subtracting the estimation frequency error from the desired wave frequency error, and adjusting the amplitude and phase delay to generate the first interference wave replica signal,
The second interference wave replica signal generating means is based on a plus frequency corresponding to a half value of a channel interval with respect to an IQ digital signal of an intermediate frequency signal of a different polarization channel adjacent to the desired wave channel at an upper frequency. The first interference wave replica signal is generated by performing complex multiplication by adding a value obtained by subtracting the estimation frequency error from the desired wave frequency error, and adjusting an amplitude and a phase delay. 6. The receiver according to 6. The desired wave signal processing means includes:
First subtraction means for subtracting the first interference wave replica signal from the IQ digital signal of the desired wave;
Second subtracting means for subtracting the second interference wave replica signal from the IQ digital signal of the desired wave;
Demodulation / decoding for performing demodulation processing and decoding processing corresponding to the encoding / modulation method on the transmission side for the IQ digital signal of the desired wave obtained by subtracting each of the first interference wave replica signal and the second interference wave replica signal Means,
From the state of the demodulated signal after the demodulation processing, an evaluation means for generating an evaluation value for adjusting the amplitude and phase delay;
The receiver according to claim 7, comprising:   The control means controls the adjustment of the amplitude and phase delay so that the state of the demodulated signal of the desired wave is closest to a normalized reference signal point of a corresponding modulation method according to the evaluation value. The receiver according to claim 8. Polarization sharing converter according to any one of claims 1 to 5,
A receiver according to any one of claims 6 to 9;
A satellite receiver characterized by comprising: A polarization sharing converter that converts a modulated wave signal in a radio frequency band of a digital signal transmitted using a plurality of types of polarization into a signal in an intermediate frequency band,
A modulated wave signal of a first polarization in a predetermined radio frequency band received via a satellite transmission path is converted into an intermediate frequency signal in a first band of an intermediate frequency band based on a local oscillation frequency signal of a first local oscillator. First frequency conversion means;
The modulated signal of the second polarized wave in the predetermined radio frequency band received via the satellite transmission path is converted into an intermediate frequency signal in the second band of the intermediate frequency band based on the local oscillation frequency signal of the second local oscillator. Second frequency converting means for converting;
Relative frequency conversion means for generating a third local oscillation frequency signal using the local oscillation frequency signals of the first local oscillator and the second local oscillator and outputting the third local oscillation frequency signal as a relative intermediate frequency signal of an unmodulated wave; ,
An output means for outputting the intermediate frequency signal of the first band, the intermediate frequency signal of the second band, and the relative intermediate frequency signal of the unmodulated wave to a receiver via a predetermined cable;
A dual-polarized converter comprising: 12. The first band intermediate frequency signal, the second band intermediate frequency signal, and the unmodulated wave relative intermediate frequency signal output from the dual-polarization converter according to claim 11 are received, and the first band intermediate frequency signal is received. A receiver capable of removing an interference wave in either one or both of the modulated wave signals of the polarized wave and the second polarized wave,
Based on the relative intermediate frequency signal of the unmodulated wave, modulation is performed by performing frequency conversion on one of the modulated wave signals of the first polarization and the second polarization desired to be received. Means for reproducing the relative intermediate frequency signal of the wave;
The channel in the intermediate frequency signal in any one of the first frequency band based on the first polarization and the second frequency band based on the second polarization is set as a desired wave. A desired wave signal processing means for generating an IQ digital signal by signal processing and deriving a desired wave frequency error by carrier reproduction;
A first interference wave replica is processed as an IQ digital signal by processing an intermediate frequency signal of the channel of the different polarization with an interference wave of the channel of the different polarization adjacent to the channel of the desired wave as a target to be removed. First interference wave replica signal generation means for generating a signal;
The intermediate frequency signal of the differently polarized channel is signal-processed to remove the interference wave from the differently polarized channel adjacent to the desired wave channel at the upper frequency, and the second interference wave replica signal as an IQ digital signal is processed. Second interference wave replica signal generating means for generating
After generating as an IQ digital signal based on the relative intermediate frequency signal of the modulated wave in the frequency band corresponding to the channel of the desired wave, the local oscillation frequency signal of the first local oscillator and the second local signal are generated by carrier recovery. A relative frequency error estimating means for deriving an estimation frequency error for estimating the relative frequency error of the local oscillation frequency signal of the oscillator;
Control means for controlling generation of the first interference wave replica signal and the second interference wave replica signal in accordance with a change in the relative frequency error estimated from the desired wave frequency error and the estimation frequency error;
A receiver comprising: Polarization sharing converter according to claim 10,
A receiver according to claim 11;
A satellite receiver characterized by comprising: