JP5505968B2 - Adaptive receiver, tap coefficient arithmetic circuit and tap coefficient arithmetic method for adaptive matched filter used therefor - Google Patents

Description

  The present invention relates to an adaptive receiver, and a tap coefficient calculation circuit and a tap coefficient calculation method for an adaptive matched filter used therefor, and more particularly to an adaptive matched filter (AMF) for a received signal that has been subjected to quadrature amplitude modulation (QAM). : Adaptive Matched Filter (DFE) and Decision Feedback Equalizer (DFE), an adaptive receiver that obtains a high-quality received signal from which intersymbol interference is removed, and tap coefficients of an adaptive matched filter used therefor The present invention relates to an arithmetic circuit and a tap coefficient calculation method.

  Patent Document 1 describes an example of an adaptive receiver that performs high-quality reception by removing distortion using AMF and DFE in a radio signal propagation path involving multipath fading. The adaptive receiver described in Patent Document 1 receives radio signals with a plurality of spatially separated antennas, and first supplies each received signal separately to a plurality of complex multipliers in the AMF. Each of the tap coefficients from the correlator provided in this manner is multiplied, and the multiplied signal is supplied to a single synthesizer for diversity combining.

  Next, the adaptive receiver amplifies the diversity combined signal output from the AMF by an automatic gain control circuit and supplies it to the correlator as a reference symbol for controlling the tap coefficient, while multipath by the DFE. Intersymbol interference due to fading is removed and output as a received signal.

  In such an adaptive receiver, the tap coefficient of AMF is generated by, for example, a tap coefficient calculation circuit shown in the block diagram of FIG. As shown in the figure, the tap coefficient calculation circuit 1 converts a reception signal composed of an in-phase signal component and a quadrature signal component into a conjugate complex signal in a complex conjugate unit 2 and then converts the conjugate complex signal into a complex multiplier 3. In FIG. 1, the reference symbol indicating the signal to be received is complex-multiplied. Then, the tap coefficient calculation circuit 1 performs time averaging on the signal after multiplication from the complex multiplier 3 in the time averaging circuit 4, and outputs a tap coefficient (correlation value) for an arbitrary period.

JP 2008-42728 A JP-A-4-271508

  However, the tap coefficient calculation circuit 1 shown in FIG. 9 has the following problems because the multiplied signal output from the complex multiplier 3 is directly input to the time averaging circuit 4.

  The first problem is that when the received signal is a signal modulated by a digital modulation method with a change in amplitude component such as QAM, fluctuation of the amplitude component due to the data pattern occurs, and therefore, quadrature modulation (QPSK: Quadrature) Compared to the case of a signal modulated by a digital modulation method with no change in amplitude component such as (Phase Shift Keying), the error from the ideal value of the tap coefficient increases, resulting in noise.

  The second problem is that a time averaging circuit having a sufficiently narrow band (that is, having a sufficiently long time average) cannot be applied as compared with a band in which a noise component falls within an allowable level required for the system. That is, in order to suppress the fluctuation of the amplitude component, it is conceivable to take a long time for the time averaging by the time averaging circuit 4, but it competes with conditions such as carrier frequency shift and fading speed. This is because, if the time average time of the time averaging circuit 4 is increased, the followability cannot be maintained depending on conditions such as low and a large frequency deviation.

  The present invention has been made in view of the above points, and even when a reception signal modulated by a digital modulation method having a change in amplitude component such as QAM is input, without sacrificing the tracking ability of the AMF. An object of the present invention is to provide an adaptive receiver capable of generating tap coefficients with reduced noise and enabling high-quality reception, and a tap coefficient calculation circuit and a tap coefficient calculation method for an adaptive matched filter used therefor.

In order to achieve the above object, the adaptive receiver of the present invention combines a received signal that is a modulated wave or a delayed received signal obtained by delaying the received signal by a predetermined time and a corresponding tap coefficient after complex multiplication, respectively. An adaptive matched filter with a transversal filter configuration that outputs a signal that has undergone adaptive matched filtering, and a signal that eliminates intersymbol interference in the received signal by performing a predetermined equalization operation on the signal output from the adaptive matched filter And a tap coefficient calculation means for performing complex multiplication of the received signal using the signal output from the decision feedback equalizer as a reference signal and calculating the tap coefficient of the adaptive matched filter The tap coefficient calculation means comprises a complex conjugate means for generating a complex conjugate signal of the received signal, and a complex of the reference conjugate signal and the complex conjugate signal output from the complex conjugate means. A complex multiplying means for performing calculations, an amplitude normalizing means for always normalized to the value on the unit circle the absolute value of the amplitude component of the complex multiplication value output from the complex multiplying means, the signal output from the amplitude normalizing means And time averaging means for generating a correlation value of an arbitrary period between the received signal and the reference signal and outputting the correlation value to the adaptive matched filter as the tap coefficient.

In order to achieve the above object, the tap coefficient arithmetic circuit of the adaptive matched filter of the present invention includes a complex conjugate means for generating a complex conjugate signal of a received signal that is a modulated wave, and at least a tap coefficient for the received signal. The complex multiplication means for performing complex multiplication of the reference signal obtained through the adaptive matched filter for performing complex multiplication of the complex conjugate signal output from the complex conjugate means, and the amplitude component of the complex multiplication value output from the complex multiplication means Amplitude normalization means that always normalizes the absolute value of the signal to a value on the unit circle, and a time average of the signal output from the amplitude normalization means, and generates a correlation value for an arbitrary period between the received signal and the reference signal And a time averaging means for outputting as a tap coefficient to the adaptive matched filter.

In order to achieve the above object, a tap coefficient calculation method according to the present invention includes a first step of generating a complex conjugate signal of a received signal that is a modulated wave, and a complex multiplication of at least the received signal by a tap coefficient. The second step of performing complex multiplication of the reference signal obtained through the adaptive matched filter for performing the complex conjugate signal obtained in the first step, and the amplitude component of the complex multiplication value obtained in the second step A third step of always normalizing the absolute value of the signal to a value on the unit circle, and a time average of the signals obtained in the third step, and generating a correlation value of an arbitrary period between the received signal and the reference signal And a fourth step of outputting as a tap coefficient to the adaptive matched filter.

Furthermore, in order to achieve the above object, a tap coefficient calculation program according to the present invention provides a computer with a first step of generating a complex conjugate signal of a received signal that is a modulated wave, and at least a tap coefficient for the received signal. The second step of performing complex multiplication of the reference signal obtained through the adaptive matched filter that performs complex multiplication of the complex conjugate signal obtained in the first step, and the complex multiplication value obtained in the second step A third step of always normalizing the absolute value of the amplitude component of the signal to a value on the unit circle, and a time average of the signals obtained in the third step, and a correlation value of an arbitrary period between the received signal and the reference signal And a fourth step of outputting as a tap coefficient to the adaptive matched filter.

  According to the present invention, noise can be reduced without sacrificing AMF tracking even when a received signal modulated by a digital modulation method having a change in amplitude component such as a QAM modulation method is input. The tap coefficient can be generated to enable high quality reception.

It is a block diagram of one Embodiment of the adaptive receiver of this invention. FIG. 2 is a block diagram of an embodiment of a control signal generation circuit in FIG. 1. 1 is a block diagram of a first embodiment of a tap coefficient calculation circuit of an adaptive matched filter of the present invention. FIG. It is a signal point arrangement | positioning figure which shows an example of the relationship between a received signal, a reference signal, and a conjugate complex signal when a received signal is a 16QAM signal. FIG. 5 is a diagram illustrating a complex multiplication value of a reception signal and a reference signal in FIG. 4. It is a figure which shows an example of the time change of the absolute value of the output of the tap coefficient arithmetic circuit of FIG. 3, and the tap coefficient arithmetic circuit of FIG. It is a figure explaining operation | movement of an amplitude normalization circuit. It is a block diagram of 2nd Embodiment of the tap coefficient calculating circuit of the adaptive matching filter of this invention. It is a block diagram which shows an example of the tap coefficient calculating circuit of related invention.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of an embodiment of an adaptive receiver according to the present invention. As shown in the figure, the adaptive receiver 10 of the present embodiment includes a signal processing unit (not shown), an adaptive matched filter (AMF) 11, and a decision feedback equalizer (DFE: Decision Feedback Equalizer). 18 and a control signal generation circuit 20.

  The AMF 11 performs adaptive matched filtering to symmetrize the asymmetric impulse response by combining the received signal, which is a modulated wave, or a delayed received signal obtained by delaying the received signal with a predetermined time and the corresponding tap coefficient after complex multiplication. This is a transversal filter that outputs the received signal. That is, the AMF 11 includes cascaded T / 2 delay units 12 and 13, a complex multiplier 14 that performs complex multiplication of the delayed reception signal output from the T / 2 delay unit 12 and the tap coefficient W0, and T / A complex multiplier 15 that performs complex multiplication of the received signal input to the two delay unit 12 and the tap coefficient W-1, and a complex multiplication of the delayed received signal output from the T / 2 delay unit 13 and the tap coefficient W1. The transversal filter is composed of a complex multiplier 16 to be performed and an adder 17 for adding signals after multiplication from the complex multipliers 14 to 16. Note that T represents a 1-bit signal period (symbol period).

  The adaptive receiver 10 performs predetermined adjustments such as gain adjustment and A / D conversion on the received signal obtained by receiving the transmission radio wave through the radio signal propagation path with multipath fading by the antenna by the signal processing unit. Signal processing. The AMF 11 performs a known adaptive matched filtering process for symmetrizing an asymmetric impulse response with respect to the reception signal signal-processed by the signal processing unit. Here, complex multipliers 14, 15 and 16 in the AMF 11 receive tap coefficients W0, W-1 and W1 output from the control signal generation circuit 20 as inputs, and complex multiplication with the received signal or the delayed received signal. I do.

  The DFE 18 performs an equalization operation with a known configuration on the post-filter signal output from the AMF 11, and outputs a reception signal from which intersymbol interference is removed. The control signal generation circuit 20 generates tap coefficients W0, W-1, and W1 as control signals from the reception signal output from the DFE 18 and the reception signal input to the AMF 11, and generates them as complex multipliers 14, 15 , 16 is output.

  Although the basic block configuration itself of the adaptive receiver 10 shown in FIG. 1 is known, the present embodiment is characterized in that the configuration in the control signal generation circuit 20, particularly the configuration of the tap coefficient arithmetic circuit, is novel. There is. In other words, the control signal generation circuit 20 sacrifices the tracking ability of the AMF 11 even when a reception signal modulated by a digital modulation method with a change in amplitude component such as QAM is input to the adaptive receiver 10. In other words, the tap coefficient with reduced noise is generated, thereby enabling high quality reception. Note that the adaptive receiver 10 of this embodiment may have one or more antennas.

FIG. 2 shows a block diagram of an embodiment of the control signal generation circuit 20 in FIG. As shown in FIG. 2, the control signal generation circuit 20 includes three delay devices 21, 22 and 23 connected in cascade, a reference signal generation circuit 24, tap coefficient calculation circuits (correlators) 25 ₁ , 25 ₂ , 25 ₃ . Delay device 21 delays the received signal by a delay time τ and outputs the received signal. The delay time τ is a time for adjusting the time delay by the reference signal generation circuit 24. As a result, the received signal output from the delay unit 21 is time aligned with the reference signal output from the reference signal generation circuit 24.

  The reference signal generation circuit 24 receives a reception signal input to the AMF 11 and a signal output from the DFE 18 as input signals, and based on these, a reference signal (reference symbol) having a value to be received by the adaptive receiver 10. Is produced by a known method. Note that the configuration of the reference signal generation circuit 24 differs depending on the system and design policy, but since it is not directly related to the present invention, the reference signal generation circuit 24 is deleted and the signal output from the DFE 18 is directly used as the reference signal. It is good.

The tap coefficient calculation circuit (correlator) 25 ₂ receives the reception signal output from the delay unit 21 and the reference signal output from the reference signal generation circuit 24 as input, and generates the tap coefficient W−1. To the complex multiplier 15. The tap coefficient calculation circuit (correlator) 25 ₁ includes a delayed reception signal output from the delay unit 22 that delays the reception signal output from the delay unit 21 by T / 2, and a reference signal output from the reference signal generation circuit 24. Are received as inputs and a tap coefficient W0 is generated and supplied to the complex multiplier 14 of FIG. The tap coefficient calculation circuit (correlator) 25 ₃ outputs the delayed reception signal output from the delay unit 23 that further delays the delayed reception signal output from the delay unit 22 by T / 2, and the reference signal generation circuit 24. The tap signal W1 is generated by receiving the reference signal as an input and supplied to the complex multiplier 16 in FIG.

The present invention is characterized by the configuration of the tap coefficient calculation circuits (correlator) 25 ₁ , 25 ₂ , 25 ₃ , and the configuration and operation of each embodiment will be described in detail below. Since the tap coefficient calculation circuits (correlator) 25 ₁ , 25 ₂ , 25 ₃ have the same configuration, only one tap coefficient calculation circuit (correlator) will be described as a representative.

(First embodiment)
FIG. 3 shows a block diagram of a first embodiment of the tap coefficient arithmetic circuit of the adaptive matched filter according to the present invention. As shown in the figure, the tap coefficient calculation circuit 25 of this embodiment includes a complex conjugate 251 to which a received signal is input, a conjugate complex signal from the complex conjugate 251 and a reference from DFE (18 in FIG. 1). A complex multiplier 252 that performs complex multiplication with a signal (reference symbol), an amplitude normalization circuit 253, and a time averaging circuit 254 are configured.

  The received signal input to the complex conjugate 251 is a QAM signal that has undergone multipath fading in the propagation path input to each tap. The complex conjugate unit 251 outputs a conjugate complex signal of this received signal. The complex multiplier 252 performs complex multiplication of the conjugate complex signal from the complex conjugate unit 251 and the reference signal. The reference signal from the DFE (18 in FIG. 1) indicates the original amplitude and phase at which the received signal is to be received.

  The amplitude normalization circuit 253 normalizes the amplitude of the multiplied signal output from the complex multiplier 252. As a calculation method for amplitude normalization in the amplitude normalization circuit 253, for example, a known method such as a CORDEC method or an amplitude division can be applied, and any method may be used.

  The time averaging circuit 254 performs time averaging on the signal output from the amplitude normalization circuit 253, and outputs a correlation value for an arbitrary period between the received signal and the reference signal. The time averaging circuit 254 can be composed of a low pass filter such as a moving average filter.

  Next, the operation of this embodiment will be described. Assuming that a 16QAM signal is input as a received signal, the complex conjugate unit 251 converts the in-phase signal component I and the quadrature signal component Q of the 16QAM signal into a conjugate complex signal and supplies the complex signal to the complex multiplier 252. To do. The complex multiplier 252 performs complex multiplication on the conjugate complex signal from the complex conjugate unit 251 and the reference symbol.

Here, the received signal is a 16QAM signal composed of 16 signal points indicated by black circles in the signal point arrangement diagram of FIG. 4, and a signal represented by (a + ja) as indicated by a solid arrow I in FIG. Suppose that The complex conjugate unit 251 generates a conjugate complex signal (a-ja) of this received signal. This conjugate complex signal (a-ja) is indicated by a dotted arrow II in FIG. Assuming that the reference signal is a signal represented by (a + ja) having the same phase and amplitude as the received signal indicated by III in FIG. 4, the complex multiplier 252 and the conjugate complex signal (a−ja) and the reference signal ( a + niv) and by multiplying the indicated by an arrow IV in FIG. 5, and outputs the complex multiplication value value is 2a ^2. In FIG. 5, it is illustrated as a = 1. As described above, when the phases of the received signal and the reference signal coincide with each other, the complex multiplication value indicates a value on the real axis of phase 0 as shown in FIG. In other words, if the complex multiplication value is a value on the real axis, it can be seen that the phases of the received signal and the reference signal are the same.

Similarly, the complex multiplier 252 has a value of 2a ² , 10a ² , 18a ² when the received signal is a signal represented by a vector other than the above and the reference signal completely matches the received signal. Any one of the following three values is output. That is, the complex multiplier 252 outputs the value 2a ² when the received signal and the reference signal are (a−ja), (−a + ja), or (−a−ja), and (a + j3a). ), (a-j3a), (3a + ja), (- a-j3a), (- a + j3a), or outputs the value 10a ² when the (-3a-ja), also, (3a + j3a), ( - 3a- J3A), and outputs the value 18a ² when the (3a-j3a), or (-3a + j3a).

  That is, the complex multiplier 252 outputs any one of the above three complex multiplication values even when the received signal and the reference signal completely match. When the signal is directly input to the time averaging circuit as in the circuit, the absolute value of the tap coefficient calculation output, which is the output of the time averaging circuit, is indicated by V in FIG. Thus, an error from the ideal value indicated by VII in FIG.

  Therefore, in this embodiment, the complex multiplication value output from the complex multiplier 252 is supplied to the time averaging circuit 254 after the amplitude component is normalized by the amplitude normalization circuit 253. Since the amplitude normalization circuit 253 always normalizes the absolute value of the amplitude component to a value on the unit circle, the amplitude component error can be removed.

Further, the amplitude normalization circuit 253, when the phase of the received signal and the reference signal do not match, for example, when a complex multiplication value represented by a vector indicated by an arrow VIII in FIG. 7 is input. As indicated by an arrow IX in the figure, the deviation angle θ1 of the input complex multiplication value is stored, and a signal represented by a normalized vector on a unit circle whose amplitude is indicated by a dotted line is output. Similarly, for example, when a complex multiplication value represented by a vector indicated by an arrow X in FIG. 7 is input, the amplitude normalization circuit 253 deviates the input complex multiplication value as indicated by an arrow XI in FIG. The angle θ2 is stored, and a signal represented by a vector normalized on a unit circle whose amplitude is indicated by a dotted line is output. The time averaging circuit 254 performs time averaging on the signal output from the amplitude normalization circuit 253, and outputs a correlation value of an arbitrary period between the received signal and the reference signal as a tap coefficient.

  As described above, according to the tap coefficient calculation circuit 25 of the present embodiment, the amplitude normalization circuit 253 can prevent the occurrence of an amplitude component error, and even when the received signal and the reference signal do not match, Since the phase component of the complex multiplication value output from the complex multiplier 252 is preserved, a coefficient with less error can be obtained while maintaining the performance as an AMF tap coefficient such as phase control and timing control.

  VI of FIG. 6 shows the time change of the absolute value of the tap coefficient which is the output of the time averaging circuit 254 in the tap coefficient calculation circuit 25 of the present embodiment, and an error from the ideal value shown by VII in FIG. It turns out that it hardly occurs. Thus, according to the present embodiment, it is possible to remove the error derived from the amplitude component of the symbol in QAM and realize tap coefficient accuracy equivalent to phase modulation such as QPSK. Therefore, according to the present embodiment, noise is reduced without sacrificing AMF tracking even when a received signal modulated by a digital modulation method with a change in amplitude component such as QAM is input. The generated tap coefficient can be generated, thereby enabling high quality reception. Further, if the amount of noise is the same, it becomes possible to improve the followability as compared with the circuit configuration of FIG.

(Second Embodiment)
Next, a second embodiment of the tap coefficient calculation circuit of the present invention will be described. FIG. 8 shows a block diagram of a second embodiment of the tap coefficient arithmetic circuit of the adaptive matched filter according to the present invention. As shown in the figure, the tap coefficient calculation circuit 30 of this embodiment includes a complex conjugate device 31 to which a received signal is input, an amplitude normalization circuit 33 to which a reference signal (reference symbol) is input, and a complex conjugate device. A complex multiplier 32 that performs complex multiplication of the conjugate complex signal from 31 and the reference signal from the amplitude normalization circuit 33 and a time averaging circuit 34 are configured.

  The tap coefficient calculation circuit 30 of the present embodiment is characterized in that the amplitude is normalized by the amplitude normalization circuit 33 only for the reference signal. The configuration of the amplitude normalization circuit 33 is the same as that of the amplitude normalization circuit 253 in FIG. Thereby, the complex multiplier 32 outputs a complex multiplication value of the conjugate complex signal from the complex conjugater 31 and the reference signal whose amplitude is normalized by the amplitude normalization circuit 33.

  Here, when the received signal and the reference signal match, the reference signal whose amplitude is normalized by the amplitude normalization circuit 33 becomes a signal whose absolute value is 1 and whose deflection angle is equal to that of the received signal. Therefore, the complex multiplication value of the conjugate complex signal of the received signal obtained by passing the received signal through the complex conjugater 31 and the amplitude-normalized reference signal has the absolute value as it is and the declination is 0. The real number of Therefore, the absolute value of the ideal received signal is any one of (√2) a, (√10) a, and 3 (√2) a. One of three values.

  The time averaging circuit 34 averages the complex multiplication value from the complex multiplier 32 and outputs a correlation value of an arbitrary period between the received signal and the reference signal as a tap coefficient.

  In the tap coefficient calculation circuit 30 of the present embodiment, since the received signal is not normalized, the range of variation of the complex multiplication value is larger than that of the first embodiment. However, when compared with the tap coefficient calculation circuit shown in FIG. 9, the present embodiment can provide a normalization effect. In addition, since the reference signal takes a known value depending on the modulation method, it is not necessary to perform a real-time normalization operation, so that the amount of calculation can be reduced. Although the normalization calculation depends on the method, processing that requires a relatively large amount of calculation such as division and arc tangent (arc tangent) is required, so this embodiment is a system that requires a reduction in the amount of calculation. This is effective when the amount of error can be tolerated.

  In the tap coefficient calculation circuits 25 and 30 according to the first and second embodiments described above, in the region where the tap coefficient (correlation value) is large, the ratio of the phase of the received signal and the reference signal is high. The effect of reducing the amplitude error by the tap coefficient calculation circuits 25 and 30 is relatively higher than that in the region where the tap coefficient (correlation value) having a low ratio of matching phases is small. Therefore, it is possible to adopt a configuration in which the tap coefficient (correlation value) calculated by the tap coefficient calculation circuits 25 and 30 is not applied to all the taps but only to the center tap where the tap coefficient (correlation value) increases. is there. At this time, a tap to be applied may be determined in advance, or may be dynamically controlled by a distribution of tap coefficients.

  The present invention is not limited to the above embodiment. For example, although the number of taps of the AMF 11 is three, the present invention is not limited to this. In the above embodiments, the input received signal is assumed to be a 16QAM signal. However, the present invention is not limited to other QAM modulation schemes such as 64QAM, amplitude phase modulation (APSK) schemes, and others. It is suitable to be applied to a received signal modulated by a digital modulation method having a change in amplitude component, but it is suitable for a digital modulation method having no change in amplitude component, such as a QPSK modulation method, a frequency modulation (FSK: Frequency Shift Keying) method, etc. The present invention can also be applied to a modulated received signal.

  Furthermore, the present invention includes a tap coefficient calculation program that causes a computer to execute the operations of the tap coefficient calculation circuits 25 and 30 shown in FIGS.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
Adaptation of a transversal filter configuration that combines a received signal that is a modulated wave or a delayed received signal obtained by delaying the received signal by a predetermined time and a corresponding tap coefficient after complex multiplication and outputs a signal subjected to adaptive matched filtering A matched filter;
A decision feedback equalizer that performs a predetermined equalization operation on the signal output from the adaptive matched filter and outputs a signal in which intersymbol interference in the received signal is removed;
The tap coefficient calculating means comprises a tap coefficient calculating means for performing complex multiplication with the received signal using the signal output from the decision feedback equalizer as a reference signal and calculating the tap coefficient of the adaptive matched filter. ,
Complex conjugate means for generating a complex conjugate signal of the received signal;
Complex multiplication means for performing complex multiplication of the reference conjugate signal and the complex conjugate signal output from the complex conjugate means;
Amplitude normalizing means for normalizing the amplitude of the complex multiplication value output from the complex multiplication means;
Time averaging means for averaging the signal output from the amplitude normalization means, generating a correlation value of the reception signal and the reference signal for an arbitrary period, and outputting the correlation coefficient to the adaptive matched filter as the tap coefficient; An adaptive receiver comprising:

(Appendix 2)
Adaptation of a transversal filter configuration that combines a received signal that is a modulated wave or a delayed received signal obtained by delaying the received signal by a predetermined time and a corresponding tap coefficient after complex multiplication and outputs a signal subjected to adaptive matched filtering A matched filter;
A decision feedback equalizer that performs a predetermined equalization operation on the signal output from the adaptive matched filter and outputs a signal in which intersymbol interference in the received signal is removed;
The tap coefficient calculating means comprises a tap coefficient calculating means for performing complex multiplication with the received signal using the signal output from the decision feedback equalizer as a reference signal and calculating the tap coefficient of the adaptive matched filter. ,
Complex conjugate means for generating a complex conjugate signal of the received signal;
Amplitude normalizing means for normalizing the amplitude of the reference signal;
Complex multiplication means for performing complex multiplication of the complex conjugate signal output from the complex conjugate means and the amplitude-normalized reference signal output from the amplitude normalization means;
Time averaging means for averaging the complex multiplication values output from the complex multiplication means, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient An adaptive receiver comprising: and.

(Appendix 3)
The adaptive receiver according to appendix 1 or 2, wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component.

(Appendix 4)
Complex conjugate means for generating a complex conjugate signal of a received signal that is a modulated wave;
Complex multiplication means for performing complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least complex multiplication of the received signal with a tap coefficient and the complex conjugate signal output from the complex conjugate means;
Amplitude normalizing means for normalizing the amplitude of the complex multiplication value output from the complex multiplication means;
Time averaging means for averaging the signal output from the amplitude normalization means, generating a correlation value of the reception signal and the reference signal for an arbitrary period, and outputting the correlation coefficient to the adaptive matched filter as the tap coefficient; A tap coefficient calculation circuit for an adaptive matched filter, comprising:

(Appendix 5)
Complex conjugate means for generating a complex conjugate signal of a received signal that is a modulated wave;
Amplitude normalizing means for normalizing the amplitude of the reference signal obtained through an adaptive matched filter that performs complex multiplication of at least the received signal with a tap coefficient;
Complex multiplication means for performing complex multiplication of the complex conjugate signal output from the complex conjugate means and the amplitude-normalized reference signal output from the amplitude normalization means;
Time averaging means for averaging the complex multiplication values output from the complex multiplication means, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient A tap coefficient calculation circuit for an adaptive matched filter, characterized by comprising:

(Appendix 6)
6. The tap coefficient arithmetic circuit for an adaptive matched filter according to appendix 4 or 5, wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component.

(Appendix 7)
A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of performing a complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least a complex multiplication with a tap coefficient on the received signal and the complex conjugate signal obtained in the first step; ,
A third step of normalizing the amplitude of the complex multiplication value obtained in the second step;
A fourth step of averaging the signal obtained in the third step, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient; A tap coefficient calculation method comprising: and.

(Appendix 8)
A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of normalizing the amplitude of a reference signal obtained through an adaptive matched filter that performs complex multiplication of at least the received signal with a tap coefficient;
A third step of performing a complex multiplication of the complex conjugate signal obtained in the first step and the amplitude-normalized reference signal obtained in the second step;
The complex multiplication value obtained in the third step is time-averaged to generate a correlation value for an arbitrary period between the received signal and the reference signal, and output to the adaptive matched filter as the tap coefficient The tap coefficient calculation method characterized by including these steps.

(Appendix 9)
9. The tap coefficient calculation method according to appendix 7 or 8, wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component.

(Appendix 10)
On the computer,
A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of performing a complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least a complex multiplication with a tap coefficient on the received signal and the complex conjugate signal obtained in the first step; ,
A third step of normalizing the amplitude of the complex multiplication value obtained in the second step;
A fourth step of averaging the signal obtained in the third step, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient; A tap coefficient calculation program characterized by causing and to be executed.

(Appendix 11)
On the computer,
A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of normalizing the amplitude of a reference signal obtained through an adaptive matched filter that performs complex multiplication of at least the received signal with a tap coefficient;
A third step of performing a complex multiplication of the complex conjugate signal obtained in the first step and the amplitude-normalized reference signal obtained in the second step;
The complex multiplication value obtained in the third step is time-averaged to generate a correlation value for an arbitrary period between the received signal and the reference signal, and output to the adaptive matched filter as the tap coefficient A tap coefficient calculation program characterized by executing the following steps.

(Appendix 12)
12. The tap coefficient calculation program according to appendix 10 or 11, wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component.

10 Adaptive receiver 11 Adaptive matched filter (AMF)
12, 13 T / 2 delay units 14, 15, 16 Complex multiplier 17 Adder 18 Decision feedback equalizer (DFE)
20 control signal generation circuit 21, 22, 23 delay unit 24 reference signal generation circuit 25, 25 ₁ , 25 ₂ , 25 ₃ , 30 tap coefficient calculation circuit (correlator)
31, 251 Complex conjugate unit 32, 252 Complex multiplier 33, 253 Amplitude normalization circuit 34, 254 Time averaging circuit

Claims (6)

Adaptation of a transversal filter configuration that combines a received signal that is a modulated wave or a delayed received signal obtained by delaying the received signal by a predetermined time and a corresponding tap coefficient after complex multiplication and outputs a signal subjected to adaptive matched filtering A matched filter;
A decision feedback equalizer that performs a predetermined equalization operation on the signal output from the adaptive matched filter and outputs a signal in which intersymbol interference in the received signal is removed;
The tap coefficient calculating means comprises a tap coefficient calculating means for performing complex multiplication with the received signal using the signal output from the decision feedback equalizer as a reference signal and calculating the tap coefficient of the adaptive matched filter. ,
Complex conjugate means for generating a complex conjugate signal of the received signal;
Complex multiplication means for performing complex multiplication of the reference conjugate signal and the complex conjugate signal output from the complex conjugate means;
Amplitude normalization means for always normalizing the absolute value of the amplitude component of the complex multiplication value output from the complex multiplication means to a value on a unit circle;
Time averaging means for averaging the signal output from the amplitude normalization means, generating a correlation value of the reception signal and the reference signal for an arbitrary period, and outputting the correlation coefficient to the adaptive matched filter as the tap coefficient; An adaptive receiver comprising: Complex conjugate means for generating a complex conjugate signal of a received signal that is a modulated wave;
Complex multiplication means for performing complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least complex multiplication of the received signal with a tap coefficient and the complex conjugate signal output from the complex conjugate means;
Amplitude normalization means for always normalizing the absolute value of the amplitude component of the complex multiplication value output from the complex multiplication means to a value on a unit circle;
Time averaging means for averaging the signal output from the amplitude normalization means, generating a correlation value of the reception signal and the reference signal for an arbitrary period, and outputting the correlation coefficient to the adaptive matched filter as the tap coefficient; A tap coefficient calculation circuit for an adaptive matched filter, comprising: 3. The tap coefficient calculation circuit for an adaptive matched filter according to claim 2 , wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component. A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of performing a complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least a complex multiplication with a tap coefficient on the received signal and the complex conjugate signal obtained in the first step; ,
A third step of always normalizing the absolute value of the amplitude component of the complex multiplication value obtained in the second step to a value on a unit circle;
A fourth step of averaging the signal obtained in the third step, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient; A tap coefficient calculation method comprising: and. 5. The tap coefficient calculation method according to claim 4 , wherein the received signal is a signal modulated by a digital modulation method having a change in amplitude component. On the computer,
A first step of generating a complex conjugate signal of a received signal that is a modulated wave;
A second step of performing a complex multiplication of a reference signal obtained through an adaptive matched filter that performs at least a complex multiplication with a tap coefficient on the received signal and the complex conjugate signal obtained in the first step; ,
A third step of always normalizing the absolute value of the amplitude component of the complex multiplication value obtained in the second step to a value on a unit circle;
A fourth step of averaging the signal obtained in the third step, generating a correlation value for an arbitrary period between the received signal and the reference signal, and outputting the correlation value to the adaptive matched filter as the tap coefficient; A tap coefficient calculation program characterized by causing and to be executed.

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