JP2020178227A - Signal quality improving method, error detection method, communication device, and computer program - Google Patents

Abstract

To provide a method capable of dealing with errors in quantization signals in communication systems.SOLUTION: A method for improving the signal quality of a signal demodulated from a delta-sigma modulation signal composed of a string of quantization signals in a communication system 10 includes changing the signal level of the quantization signals. A second communication device 12 includes an error compensator 151 that changes the signal level of a quantizer in which an error is detected.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to methods for improving signal quality, error detection methods, communication devices and computer programs.

Patent Document 1 discloses a transmitter that outputs a delta-sigma modulation signal output from a delta-sigma modulator to a signal transmission line. A delta-sigma modulated signal consists of a sequence of quantization signals. According to the technique disclosed in Patent Document 1, a radio frequency signal can be transmitted as a quantized signal sequence which is a digital signal. The delta-sigma modulated signal is demodulated by passing through a filter on the receiving side. For example, if the delta-sigma modulation signal is a demodulated radio frequency signal, the delta-sigma modulation is demodulated into a radio frequency signal by passing through a filter.

Japanese Unexamined Patent Publication No. 2013-220437

When a delta-sigma modulated signal is transmitted to a transmission line, noise may be applied in the transmission line. When noise is applied, an error may occur in the quantized signal. If the quantization signal is erroneous, the quality of the signal demodulated from the delta-sigma modulated signal deteriorates.

Therefore, it is desirable to deal with errors that occur in the quantization signal.

One aspect of the present disclosure is a method of improving the signal quality of a signal demodulated from a delta-sigma modulated signal consisting of a sequence of quantized signals. The method of disclosure comprises changing the signal level of the quantization signal.

In another aspect of the present disclosure, a method for improving signal quality is to obtain a first signal quality value, obtain a second signal quality value, and compare the first signal quality value with the second signal quality value. Based on, the target quantization signal includes determining the signal level of the target quantization signal, the target quantization signal is a quantization signal included in the column, and the first signal quality value is a signal of the target quantization signal. The level is a signal quality value when the level is the first level, and the second signal quality value is a signal when the signal level of the target quantization signal is a second signal level different from the first level. It is a quality value.

Yet another aspect of the present disclosure is an error detection method for a delta-sigma modulated signal consisting of a sequence of quantized signals. The disclosed method comprises detecting an error in the quantized signal based on a change in the signal quality value demodulated from the delta-sigma modulated signal when the signal level of the quantized signal is changed. ..

Yet another aspect of the present disclosure is a communication device. The disclosed communication device includes a receiver that receives a delta sigma modulated signal consisting of a sequence of quantized signals, and a signal quality value demodulated from the delta sigma modulated signal when the signal level of the quantized signal is changed. A detector for detecting an error in the quantization signal based on the change in the above.

Yet another aspect of the present disclosure is a computer program for detecting errors in a sequence of quantized signals representing analog signals. The disclosed computer program causes the computer to detect an error in the quantization signal based on a change in the signal quality value demodulated from the delta sigma modulation signal when the signal level of the quantization signal is changed. Let it run.

According to the present disclosure, errors that occur in the quantized signal can be dealt with.

FIG. 1 is a block diagram of a communication system. FIG. 2 is a hardware configuration diagram of the second communication device. FIG. 3 is a circuit model showing the influence of noise on the transmission line. FIG. 4 is an error generation model equivalent to the circuit model of FIG. FIG. 5 is a diagram of error data Cn and error time waveform ΣChn (t−Tn). FIG. 6 is a power spectrum of a delta-sigma modulated signal. FIG. 7 is a flowchart of error detection and compensation processing. FIG. 8 is a diagram showing an error detection result. FIG. 9 is a block diagram of a communication system according to a modified example. FIG. 10 is a flowchart of error detection and compensation processing according to a modified example.

[Explanation of Embodiments of the present disclosure]

(1) The method according to the embodiment is a method for improving the signal quality of a signal demodulated from a delta-sigma modulated signal composed of a sequence of quantized signals. The method according to the embodiment includes changing the signal level of the quantized signal. Since the signal level of the quantized signal affects the signal quality of the signal demodulated from the delta sigma modulated signal, the signal quality can be improved by changing the signal level of the quantized signal. The signal quality is, for example, the adjacent channel leakage power ratio or the SN ratio.

(2) The method according to the embodiment is a method for improving the signal quality of a signal demodulated from a delta-sigma modulated signal composed of a sequence of quantized signals. In the method according to the embodiment, the first signal quality value is obtained, the second signal quality value is obtained, and the signal of the target quantization signal is obtained based on the comparison result between the first signal quality value and the second signal quality value. Includes determining the level. The target quantization signal is a quantization signal included in the column. The first signal quality value is a signal quality value when the signal level of the target quantization signal is the first level. The second signal quality value is a signal quality value when the signal level of the target quantization signal is a second signal level different from the first level. Since the signal quality value changes depending on which signal level the target quantized signal takes, an appropriate signal level of the target quantized signal can be determined by considering the signal quality value for each signal level.

(3) The method according to the embodiment is an error detection method for a delta-sigma modulated signal composed of a sequence of quantized signals. The method according to the embodiment is to detect an error in the quantized signal based on a change in the signal quality value demodulated from the delta-sigma modulated signal when the signal level of the quantized signal is changed. Including. Since the error of the quantized signal affects the demodulated signal quality value, the error of the quantized signal can be detected from the change of the signal quality value corresponding to the change of the signal level of the quantized signal.

(4) The error of the quantized signal is detected when the signal level of the quantized signal is changed and the signal quality value demodulated from the delta-sigma modulated signal is improved. preferable. If the signal quality value is improved by changing the signal level, it can be determined that the signal level before the change is incorrect.

(5) The signal quality is preferably the adjacent channel leakage power ratio. In this case, the adjacent channel leakage power ratio of the demodulated signal can be improved.

(6) The communication device according to the embodiment is a receiver that receives a delta sigma modulated signal composed of a sequence of quantized signals, and demodulates from the delta sigma modulated signal when the signal level of the quantized signal is changed. A detector for detecting an error in the quantization signal based on the change in the signal quality value obtained is provided.

(7) It is preferable to further include an error compensator for changing the signal level of the quantized signal in which an error is detected by the detector. In this case, the detected error can be compensated.

(8) The detector is configured to detect an error in the target quantization signal included in the column based on the comparison result between the first signal quality value and the second signal quality value, and the first signal quality. The value is a signal quality value when the signal level of the target quantization signal is the first level, and the second signal quality value is such that the signal level of the target quantization signal is the first level. It is preferably a signal quality value when the second signal level is different.

(9) The computer program according to the embodiment is a computer program for detecting an error in a sequence of quantization signals representing an analog signal. The computer program according to the embodiment performs an operation of detecting an error in the quantized signal based on a change in the signal quality value demodulated from the delta-sigma modulated signal when the signal level of the quantized signal is changed. Let the computer do it. Computer programs are stored on computer-readable, non-temporary storage media.

[Details of Embodiments of the present disclosure]

FIG. 1 shows a communication system 10 according to an embodiment. The communication system 10 includes a first communication device 11 and a second communication device 12. The first communication device 11 transmits a signal to the second communication device 12. The signal propagates in the signal transmission line 15. The transmission line 15 may be a wireless transmission line or a wired transmission line such as an optical fiber.

The first communication device 11 includes a delta-sigma modulator (DSM) 111. The delta-sigma modulator 111 outputs a delta-sigma-modulated signal obtained by delta-sigma-modulating the original signal. In the following, the original signal is, for example, a radio frequency signal.

The delta-sigma modulator 111 is, for example, a bandpass-delta-sigma modulator (bandpass-DSM; BP-DSM). In an embodiment, the delta-sigma modulator 111 is a 1-bit delta-sigma modulator. That is, the delta-sigma modulator 111 of the embodiment outputs a binary quantization signal. Here, the quantized signal takes a value (signal level) of either +1 or -1. +1 and -1 correspond to the strength of the transmitted signal. For example, in the case of optical signal transmission, strong light corresponds to +1 and weak light corresponds to -1. In the case of electric signal transmission, a high voltage corresponds to +1 and a low voltage corresponds to -1. The signal level taken by the quantized signal is not limited to two, and may be three or more.

The delta-sigma modulator 111 outputs a sequence of quantization signals generated by delta-sigma modulation, that is, a pulse sequence. At the time of signal transmission, the delta-sigma modulated signal has a signal waveform in which a plurality of quantization signals are arranged in the time direction. One quantization signal is a signal for one sampling period in a sequence of quantization signals, that is, one sample. Each sample takes a value of either +1 or -1.

The delta-sigma modulated signal has components of the original signal such as a radio frequency signal. Therefore, the original signal is demodulated by passing the delta-sigma modulated signal through a filter such as a bandpass filter.

The first communication device 11 outputs the delta-sigma modulated signal to the transmission line 15. The second communication device 12 receives the delta-sigma modulation signal transmitted by the first communication device 11. As described above, the transmission between the first communication device 11 and the second communication device 12 is a digital signal transmission in which a delta-sigma modulated signal which is a pulse train is transmitted.

The second communication device 12 includes a receiver 121. The receiver 121 receives the delta-sigma modulated signal transmitted through the transmission line 15. The receiver 121 includes a comparator 122. The comparator 122 determines whether the signal level of the received signal is +1 or -1. That is, the comparator 122 binarizes the received signal. The level of the received signal may fluctuate due to noise application during transmission. Therefore, when the receiver 121 binarizes the received signal, an error may occur. The error occurs when the receiver 121 determines that the transmitted quantization signal is +1 but -1. Further, the error occurs when the receiver 121 determines that the transmitted quantization signal is -1, but is +1.

The second communication device 12 includes a buffer 123. The buffer 123 stores the signal binarized by the comparator 122, that is, the quantized signal whose signal level is determined by the receiver 121. The buffer 123 stores a plurality of quantization signals. Here, the buffer 123 has a capacity capable of storing at least N quantization signals (N is an integer of 2 or more) for a predetermined time interval.

The second communication device 12 includes an error detector 131 that detects an error in the received quantization signal. The error detector 131 of the embodiment reads the quantization signal stored in the buffer 123 and performs error detection. Details of the error detector 131 will be described later.

The second communication device 12 includes an error compensator 151. The error compensator 151 changes the signal level of the quantized signal in which an error is detected. When the quantized signal is binary, the signal level change may be the inversion of the signal level. That is, when it is detected that the quantization signal having a signal level of +1 is an error, the error compensator 151 inverts the signal level of the quantization signal to -1. Further, when it is detected that the quantization signal having a signal level of -1 is an error, the error compensator 151 inverts the signal level of the quantization signal to +1. When the quantized signal has three or more values, the error compensator 151 changes the signal level of the quantized signal to another appropriate signal level.

FIG. 2 shows the hardware configuration of the second communication device 12. The second communication device 12 includes a computer 200 that executes error detection and error compensation processing. The computer 200 includes a processor 210 and a storage device 220. The computer 200 is connected to the receiver 121. The computer 200 receives the quantization signal from the receiver 121 and stores the quantization signal in the storage device 220 functioning as the buffer 123.

The storage device 220 stores a computer program 230 that causes the computer 200 to function as an error detector 131 and an error compensator 151. The storage area in which the computer program 230 is stored and the storage area that functions as the buffer 123 may be configured by separate storage devices.

The processor 210 reads and executes the computer program 230 stored in the storage device 220. The computer program 230 causes the processor 210 to execute the error detection and compensation process 211. The computer program 230 includes a program code that causes the processor 210 to perform an error detection operation and a program code that causes the processor 210 to perform an error compensation operation. The processor 210 that has executed the error detection operation functions as the error detector 131 shown in FIG. The processor 210 that has executed the error compensation operation functions as the error compensation device 151 shown in FIG. Note that at least one of the error detector 131 and the error compensator 151 may be configured by a hardware logic circuit instead of being realized by software.

The details of the error detector 131 will be described below, but for easy understanding, the influence of noise on the transmission of the delta-sigma modulated signal will be described prior to the description of the error detector 131 itself.

FIG. 3 shows a circuit model M1 showing the influence of noise on the transmission line 15. As shown in FIG. 3, the delta-sigma modulation signal output from the delta-sigma modulator 111 is transmitted through the transmission line 15. Noise is applied to the delta-sigma modulated signal during transmission. At the transmission destination, each quantized signal included in the delta-sigma modulated signal is subjected to signal level determination, that is, binarization by a comparator. However, if the quantized signal to which noise is applied is binarized, an error may occur. When the binarized signal sequence, that is, the quantized signal sequence is passed through the bandpass filter 132, it is demodulated to the radio frequency signal f (t) which is the original signal. However, if a quantization signal sequence including an erroneous quantization signal is passed through the bandpass filter 132, the signal quality of the obtained signal f (t) deteriorates. For example, if there is an erroneous quantization signal, the adjacent channel leakage power ratio (ACLR) of the signal f (t) deteriorates.

An error due to noise occurs when the signal level of the transmitted quantization signal is +1 but changes to -1 due to noise. Further, an error occurs when the signal level of the transmitted quantization signal is -1, but changes to +1 due to noise.

FIG. 4 shows error generation models M2, M3, and M4 that are equivalent to the circuit model M1 of FIG. As the error occurrence model M2, the error can be interpreted as an error data C _n is added to the delta-sigma modulated signal. That is, the signal level by the noise changes to -1 +1 can be considered to adder 301 present in the transmission path 15, and the error data C _{n =} -2 is added. The signal level by the noise changes from -1 to +1 are the adder 301, it can be considered that the error data C _{n =} + 2 was added. If there is no influence of noise, the adder 301, it can be considered that the error data C _{n =} 0 were added.

In the error generation model M3 shown in FIG. 4, the bandpass filter 132 included in the error generation model M2 is replaced by the bandpass filters 321 and 322 provided in front of the adder 301.

In the error generation model M4 shown in FIG. 4, the signal given to the adder 301 from the bandpass filter 322 of the error generation model M3 is obtained by multiplying the impulse response h (t) of the bandpass filter 322 by the error data C _n. It has been changed to _n h (t-T _n ). Note that T _n is the reciprocal of the time transmission rate of 1 bit (one quantization signal) of the delta-sigma modulated signal.

FIG. 5 shows an example of the error E1 given to the error generation model M4. The error E1 shown in FIG. 5 includes an error data C _n and an error time waveform ΣC _n h (tT _n ). In FIG. 5, seven error data Cns, which are +2 or -2, are provided. Error time instant of occurrence of the error data _{C n} is +2 Also -2 waveform _{C n h (t-T n} ) is, _{C n} multiplied by the error data _{C n} the impulse response h of the band-pass filter 322 (t) It is h (t-T _n ).

FIG. 6 shows an example of the power spectrum S of the delta-sigma modulated signal. The power spectrum S shown in FIG. 6 is the power spectrum of a delta-sigma modulated signal (“BP-DSM without error” in FIG. 6) consisting of 131072 samples (131072 quantization signals) and 131 in the same delta-sigma modulated signal. Includes the power spectrum (“BP-DSM with error” in FIG. 6) when the error data C _n which is +2 or -2 is inserted into the sample. The error rate of "BP-DSM with error" is 10 ^-4 . The resolution bandwidth (RBW) in FIG. 6 is 78.1 kHz.

As shown in FIG. 6, the adjacent channel leakage power ratio (ACLR) in "BP-DSM without error" is 52.0 dB, 52.2 dB, 50.5 dB, 51.4 dB in order from the lowest frequency channel. On the other hand, the adjacent channel leakage power ratio (ACLR) in "BP-DSM with error" is 35.3 dB, 36.1 dB, 36.6 dB, and 36.2 dB in order from the channel having the lowest frequency. As is clear from FIG. 6, in "BP-DSM with error", the adjacent channel leakage power is increased, and the signal quality indicated by the adjacent channel leakage power ratio is deteriorated.

In this way, the adjacent channel leakage power ratio, which is the signal quality value, is affected by the error of the quantized signal. Therefore, if the signal quality is improved when the signal level of a quantized signal is changed, it can be detected that the quantized signal is erroneous. That is, it can be determined that the quantized signal before the signal level change is incorrect and the quantized signal after the signal level change is correct. On the other hand, if the signal quality deteriorates when the signal level of a certain quantized signal is changed, it can be determined that the quantized signal before the signal level change is correct.

Further, when the quantized signal can have a signal level of 3 or more, it can be determined that the signal level at which the signal quality is the best is correct and the other signal levels are incorrect. Error compensation can be achieved by changing to a signal level that gives the best signal quality.

According to the above, the error of the quantized signal can be considered as the addition of error data C _n to the quantization signal. Therefore, so as to cancel the error data C _n, it can be changed the signal level of the quantized signal, to compensate for errors, to improve the signal quality. In addition, since an error in the quantized signal affects the quality of the signal demodulated from the delta-sigma modulated signal, the presence or absence of an error is determined by the change in the signal quality value when the signal level of the quantized signal is changed. Can be detected.

The error detector 131 shown in FIG. 1 is configured from the above viewpoint.

The error detector 131 shown in FIG. 1 includes a bandpass filter 132 that passes a delta-sigma modulation signal composed of N quantization signals read from the buffer 123. When the delta-sigma modulation signal received by the second communication device 12 contains an error, the output of the bandpass filter 132 has an error waveform ΣC _n h (t−T _n ) in the original signal waveform f (t). The added f (t) + ΣC _n h (t−T _n ) is obtained (see the error generation model M4 in FIG. 4).

The error detector 131 includes a multiplier 134 that multiplies the impulse response h (t) of the bandpass filter 132 by the compensation data D _n . The compensation data D _n takes any one of -2, 0, and +2. The compensation data D _n is used to offset the error data C _n . The error detector 131 includes an adder 133 that adds the output of the multiplier 134 to the output f (t) of the bandpass filter 132.

The error detector 131 includes an ACLR measuring device 135 to which the output of the adder 133 is given. The ACLR measuring instrument 135 is an example of a signal quality measuring instrument. The ACLR measuring instrument 135 obtains the adjacent channel leakage power ratio of the output signal of the adder 133, that is, the signal quality value.

The error detector 131 includes a comparator 136 that compares a plurality of ACLRs output from the ACLR measuring device 135. The presence or absence of an error in the quantized signal is detected from the comparison result by the comparator 136. If there is an error, the error compensator 151 corrects the error in the quantization signal.

FIG. 7 shows the processing executed by the error detector 131 and the error compensator 151 shown in FIG.

First, in step S11 shown in FIG. 7, the error detector 131 sets the variable n to 1. In step S12, the error detector 131 provides stored in the buffer 123, the N predetermined time interval partial quantized signal _Q 1 to Q _N to the band-pass filter 132. At this time, the compensation data D _n is set to 0. Therefore, the output of the bandpass filter 132 is given to the ACLR measuring instrument 135 without the addition of D _n h (t−T _n ) in the adder 133. That, ACLR when those N number of the quantized signal _Q 1 to Q _N which is stored in the buffer 123 has passed through the band-pass filter 132 is measured. The ACLR measured in step S12 is referred to as a first ACLR or a first signal quality value.

In step S13, the error detector 131 reads the _nth quantized signal Q _n out of the _N quantized signals Q _{1 to} Q _N from the buffer 123. In step S14, the error detector 131 determines the signal level of the quantized signal Q _n . When the signal level of the quantization signal Q _n is -1, the compensation data D _n is set to +2 in step S15, and when the signal level is +1 the compensation data D _n is set to -2 in step S16.

In step S17, the error detector 131 provides stored in the buffer 123, the N predetermined time interval partial quantized signal _Q 1 to Q _N to the band-pass filter 132. The output of the band-pass filter 132, the adder _{133, D n h (t-} T n) are added. The output of the adder 133 is given to the ACLR measuring instrument 135. That is, of the N quantized signal Q ₁ to Q _N which is stored in the buffer 123, that n-th signal level of the quantized signal Q _n is inverted, ie compensated by the compensation data D _n, but The ACLR when passing through the bandpass filter 132 is measured. The ACLR measured in step S17 is referred to as a second ACLR or a second signal quality value.

In step S18, the error detector 131 compares the first ACLR with the second ACLR. When the quality of the second ACLR is better than that of the first ACLR, it is detected in step S19 that the quantization signal Q _n is erroneous. If the quantized signal Q _n is an error in step S20, the error compensator 151 inverts the quantized signal Q _n, i.e., changes the quantized signal Q _n to another signal level.

The process from step S13 to step S20 is repeated until n changes from 1 to N (see steps S21 and S22). By repeating, the presence or absence of an error is detected for each of the N quantization signals, and if there is an error, it is compensated. Error compensation can improve the quality of the signal demodulated from the delta-sigma modulated signal stored in buffer 123.

FIG. 8 shows an example of error E2. Example E2 of the error shown in FIG. 8 includes "Er data" and "Decoder Er data". “Er data” shown in FIG. 8 indicates the time position of the error data C _n experimentally applied to the delta-sigma modulated signal. Also, it is shown in FIG. 8 "Decoder Er data", in the delta-sigma modulated signal error data C _n is applied, shows the time position of the actual quantized signal in which an error is detected by the error detector 131. As shown in FIG. 8, the error detector 131 can correctly detect the inserted error.

FIG. 9 shows a modified example. In the modified example, the configuration of the error detector 131 is different from that of the error detector 131 of FIG. As for the points not particularly explained in the modified example, the existing explanations are used.

Error detector 9 131, a first band-pass filter 141 as N-number of the quantized signal _Q 1 to Q _N which is stored in the buffer 123 is given, the second given via the level inverter 142 It includes a bandpass filter 143. The output of the first bandpass filter 141 is given to the first ACLR measuring instrument 145. The ACLR measured by the first ACLR measuring device 145 is referred to as the first ACLR or the first signal quality value. The output of the second bandpass filter 143 is given to the second ACLR measuring instrument 146. The ACLR measured by the second ACLR measuring device 146 is referred to as the second ACLR or the second signal quality value. The error detector 131 includes a comparator 148. The comparator 148 compares the first ACLR with the second ACLR and detects the presence or absence of an error.

FIG. 10 shows the processing executed by the error detector 131 and the error compensator 151 shown in FIG.

First, in step S101 shown in FIG. 10, the error detector 131 sets the variable n to 1. In step S102, the error detector 131 provides stored in the buffer 123, the N predetermined time interval partial quantized signal _Q 1 to Q _N to a first band-pass filter 141. The output of the first bandpass filter 141 is given to the first ACLR measuring device 145, and the first ACLR is measured.

In step S107, the error detector 131 has only the signal level of the _nth quantization signal Q _n out of the _N quantization signals Q _{1 to} Q _N for a predetermined time interval stored in the buffer 123. The determined quantization signal sequence is given to the second bandpass filter 143. The output of the second bandpass filter 144 is given to the second ACLR measuring instrument 146, and the second ACLR is measured.

In step S108, the error detector 131 compares the first ACLR with the second ACLR. When the quality of the second ACLR is better than that of the first ACLR, it is detected in step S109 that the quantization signal Q _n is erroneous. If the quantized signal Q _n is an error in step S110, the error compensator 151 inverts the quantized signal Q _n, i.e., changes the quantized signal Q _n to another signal level.

The process from step S107 to step S110 is repeated until n changes from 1 to N (see steps S11 and S112). By repeating, the presence or absence of an error is detected for each of the N quantization signals, and if there is an error, it is compensated. Error compensation can improve the quality of the signal demodulated from the delta-sigma modulated signal stored in buffer 123.

[Additional Notes]

It should be noted that the embodiments disclosed this time are examples in all respects and are not restrictive. The scope of the present invention is indicated by the scope of claims, not the above-mentioned meaning, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

10: Communication system 11: First communication device 12: Second communication device 15: Transmission line 111: Delta sigma modulator 121: Receiver 122: Comparator 123: Buffer 131: Error detector 132: Bandpass filter 133: Adder 134: Multiplier 135: ACLR measuring device 136: Comparer 141: First bandpass filter 142: Level inverter 143: Second bandpass filter 144: Second bandpass filter 145: First ACLR measuring device 146: Second ACLR measurement vessel 148: comparator 151: the error compensator 200: computer 210: processor 211: error detection compensation 220: storage device 230: computer program 301: adder 321: bandpass filter 322: bandpass filter _{C n:} error data D _n : Compensation data h (t): Impulse response M1: Circuit model M2: Error generation model M3: Error generation model M4: Error generation model Qn: Quantized signal

Claims (9)

A method of improving the signal quality of a signal demodulated from a delta-sigma modulated signal consisting of a sequence of quantized signals.
A method of improving signal quality, including changing the signal level of the quantized signal. A method of improving the signal quality of a signal demodulated from a delta-sigma modulated signal consisting of a sequence of quantized signals.
Find the quality value of the first signal,
Find the second signal quality value,
Including determining the signal level of the target quantized signal based on the result of comparison between the first signal quality value and the second signal quality value.
The target quantization signal is a quantization signal included in the column.
The first signal quality value is a signal quality value when the signal level of the target quantization signal is the first level.
The second signal quality value is a method for improving signal quality, which is a signal quality value when the signal level of the target quantization signal is a second signal level different from the first level. An error detection method for a delta-sigma modulated signal consisting of a sequence of quantization signals.
An error detection method including detecting an error in the quantized signal based on a change in a signal quality value demodulated from the delta-sigma modulated signal when the signal level of the quantized signal is changed. The error of the quantization signal is detected by claim 3 in which the signal quality value demodulated from the delta-sigma modulated signal is improved when the signal level of the quantization signal is changed. Error detection method. The method according to any one of claims 1 to 4, wherein the signal quality is an adjacent channel leakage power ratio. A receiver that receives a delta-sigma modulated signal consisting of a sequence of quantization signals,
A detector that detects an error in the quantized signal based on a change in the signal quality value demodulated from the delta-sigma modulated signal when the signal level of the quantized signal is changed.
A communication device equipped with. The communication device according to claim 6, further comprising an error compensator for changing the signal level of the quantized signal in which an error is detected by the detector. The detector is configured to detect an error in the target quantization signal included in the column based on the result of comparison between the first signal quality value and the second signal quality value.
The first signal quality value is a signal quality value when the signal level of the target quantization signal is the first level.
The communication device according to claim 6 or 7, wherein the second signal quality value is a signal quality value when the signal level of the target quantization signal is a second signal level different from the first level. A computer program for detecting errors in a sequence of quantization signals representing analog signals.
A computer program that causes a computer to perform an operation of detecting an error in the quantized signal based on a change in the signal quality value demodulated from the delta sigma modulated signal when the signal level of the quantized signal is changed.

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