WO2013155917A1 - 信号解调方法和装置 - Google Patents

信号解调方法和装置 Download PDF

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Publication number
WO2013155917A1
WO2013155917A1 PCT/CN2013/073073 CN2013073073W WO2013155917A1 WO 2013155917 A1 WO2013155917 A1 WO 2013155917A1 CN 2013073073 W CN2013073073 W CN 2013073073W WO 2013155917 A1 WO2013155917 A1 WO 2013155917A1
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Prior art keywords
constellation
demodulation
bit
signal
symbol probability
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PCT/CN2013/073073
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English (en)
French (fr)
Inventor
迪米特里•里亚布科夫
严茜
王光健
Original Assignee
华为技术有限公司
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP13778179.5A priority Critical patent/EP2830272B1/en
Publication of WO2013155917A1 publication Critical patent/WO2013155917A1/zh
Priority to US14/516,126 priority patent/US9172500B2/en

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00Arrangements for detecting or preventing errors in the information received
    • H04L1/004Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0045Arrangements at the receiver end
    • H04L1/0054Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/32Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38Demodulator circuits; Receiver circuits
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00Baseband systems
    • H04L25/02Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/06Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
    • H04L25/067Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection providing soft decisions, i.e. decisions together with an estimate of reliability

Definitions

  • the present invention relates to communication technologies, and in particular, to a signal demodulation method and apparatus. Background technique
  • MIMOAM Multiple Quadrature Amplitude Modulation
  • high-order modulation is sensitive to factors such as phase noise and Gaussian noise during signal transmission. These noises cause the received signal at the receiving end to randomly move or rotate compared with the correct corresponding modulation constellation point, affecting the receiving end to the received signal.
  • the decision of the corresponding transmitted signal of the transmitted signal may demodulate the erroneous modulation constellation point and the corresponding data bit.
  • Embodiments of the present invention provide a signal demodulation method and apparatus to improve the ability of a demodulation algorithm to resist phase noise.
  • a first aspect of the embodiments of the present invention provides a signal demodulation method, including: acquiring a received signal and a symbol probability parameter of the received signal, where the symbol probability parameter includes: a magnitude and a phase of the received signal Angle ⁇ , the magnitude and phase angle of each constellation point in the set of constellation points, and the standard deviation of the Gaussian noise" and the standard deviation of the phase noise; the set of decision constellation points is located in the modulation required to perform signal demodulation In the constellation diagram;
  • Demodulation is performed according to the symbol probability, and demodulation information is output, and the demodulation information corresponds to a data bit corresponding to the transmission signal.
  • a signal demodulating apparatus including: a parameter acquiring unit, configured to acquire a received signal and a symbol probability parameter of the received signal, where the symbol probability parameter includes: a magnitude of the received signal ⁇ and the phase angle, the magnitude and phase angle of each constellation point in the set of constellation points, and the standard deviation of the Gaussian noise" and the standard deviation of the phase noise; the set of decision constellation points is located for performing signal demodulation Modulation in the constellation; '
  • a probability calculation unit configured to calculate, according to the symbol probability parameter, a symbol probability that a transmission signal corresponding to the received signal is a constellation point ⁇ in the set of decision constellation points;
  • a demodulation processing unit configured to perform demodulation according to the symbol probability, and output demodulation information, where the demodulation information corresponds to a data bit corresponding to the transmission signal.
  • FIG. 1 is a schematic diagram of a system for applying a signal demodulation method according to an embodiment of the present invention
  • FIG. 2 is a schematic structural view of a dual polarization multiplexing system to which a signal demodulation method is applied according to an embodiment of the present invention
  • FIG. 3 is a schematic structural diagram of a MIMO system to which a signal demodulation method is applied according to an embodiment of the present invention
  • FIG. 4 is a schematic structural diagram of a dual polarization multiplexing combined MIMO system applied to a signal demodulation method according to an embodiment of the present invention
  • FIG. 5 is a schematic flowchart diagram of an embodiment of a signal demodulation method according to the present invention.
  • FIG. 6 is a schematic diagram of an experimental chart of an embodiment of a signal demodulation method according to the present invention.
  • FIG. 7 is a schematic diagram of a sector decision region selected in another embodiment of the signal demodulation method of the present invention.
  • FIG. 8 is a schematic diagram of a square decision region selected in another embodiment of the signal demodulation method of the present invention.
  • Demodulation Method A schematic diagram of a square decision region selected in an embodiment;
  • FIG. 10 is a schematic structural diagram of an embodiment of a signal demodulating device according to the present invention.
  • a signal demodulation method according to an embodiment of the present invention is applied to a digital point-to-point microwave, millimeter wave, E-Band transmission system, and mobile cellular communication.
  • a communication system such as a system, a wireless local area network system, a wireless metropolitan area network system, or a wireless personal area network system, it is mainly used for a receiver in a communication system to process a received signal.
  • FIG. 1 is a schematic diagram of a system for applying a signal demodulation method according to an embodiment of the present invention.
  • a coding unit of a transmitter encodes a signal to be transmitted to form an information sequence, and a digital signal processing unit Signal modulation, that is, transforming the information sequence into a signal suitable for channel transmission, and then transmitting it by the RF front-end unit after digital-to-analog conversion by a digital-analog converter (DAC), and the transmitted signal can be called transmission. signal.
  • DAC digital-analog converter
  • the signal transmitted by the RF front-end unit of the receiver may be referred to as a received signal, and the analog-to-digital converter (ADC) performs analog-to-digital conversion on the received signal, and is demodulated by the digital signal processing unit. That is, the distorted digital signal affected by the noise in the channel transmission is recovered and the information sequence is obtained for the decoding unit to perform error detection or error correction.
  • the digital signal processing unit of the receiver uses the signal demodulation method provided by the embodiment of the present invention.
  • the signal demodulation method of the embodiment of the present invention can also be applied to a system using dual polarization multiplexing and cross polarization interference cancellation (XPIC) technology, and multiple input multiple output (MIMO).
  • XPIC dual polarization multiplexing and cross polarization interference cancellation
  • MIMO multiple input multiple output
  • FIG. 2 is a signal demodulation according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a MIMO system to which a signal demodulation method is applied according to an embodiment of the present invention
  • FIG. 4 is a bipolar application of a signal demodulation method according to an embodiment of the present invention. The schematic diagram of the combination of multiplexing and multiplexing is combined with the MIMO system.
  • the transmission signal refers to a signal generated by a digital signal processing unit of the transmitter, for example, as described in FIG.
  • the received signal refers to a signal received by a digital signal processing unit of the receiver, such as described in FIG. 1, and the set of decision constellation points refers to a selected one of the modulation constellations referenced at the time of receiver demodulation.
  • the signal demodulation method of the embodiment is used to identify which constellation point corresponding to the received signal from the set of decision constellation points, and after identifying the corresponding constellation point, according to the "constellation point-data bit
  • the mapping table "gets the data bits corresponding to the constellation points, and the data bits are the data bits corresponding to the received information, thereby completing the demodulation of the received signal; those skilled in the art can understand that the demodulation is performed in the soft decision (described later)
  • the output is not a data bit but a soft message, and subsequent data bits can be obtained according to the soft information.
  • FIG. 5 is a schematic flowchart of a signal demodulation method according to an embodiment of the present invention. As shown in FIG. 5, the signal demodulation method of this embodiment includes:
  • the received signal is a channel-transmitted signal received by the radio front-end unit of the receiver
  • the symbol probability parameter is a parameter used in the calculation of the symbol probability in 502, which may include : the amplitude and phase angle of the received signal, the magnitude and phase angle of each constellation point in the set of constellation constellation points, and the standard deviation of the Gaussian noise and the standard deviation of the phase noise, the set of decision constellation points being located Signal modulation is required in the modulation constellation.
  • the transmitting signal corresponding to the received signal refers to a signal transmitted by a radio frequency front end unit of the transmitter, and the transmitted signal is received by a radio frequency front end unit of the receiver after being transmitted through the channel, and is referred to as receiving at this time. signal.
  • the calculation can be performed according to the following formula (1):
  • the obtained symbol probability is a posterior probability of each constellation point in the set of constellation points.
  • the signal demodulation method of this embodiment simultaneously considers the influence of Gaussian noise and phase noise on the signal, and The anti-interference ability of phase noise in signal demodulation is also greatly improved, and it has better anti-interference ability when the phase noise is large.
  • the demodulation according to the symbol probability refers to that the hard decision demodulation or the soft decision solution can be continued according to the symbol probability of each constellation point ⁇ in the set of decision constellation points obtained by formula (1).
  • the modulation (the two demodulation methods are described in detail later), and the demodulation information obtained after the decision is output to the decoding unit.
  • the demodulation information corresponds to the data bit corresponding to the transmission signal, and may include two cases. In one case, in the hard decision demodulation, the demodulation information is the data bit corresponding to the transmission signal, that is, the data bit is directly output; Another case is that in soft decision demodulation, the demodulated information is soft information for generating data bits corresponding to the transmitted signal.
  • the demodulation mode can be divided into hard decision demodulation and soft decision demodulation.
  • the constellation point corresponding to the transmission signal (the transmission signal here is a transmission symbol commonly referred to in the art, which is referred to as a transmission signal in the embodiment of the present invention) is directly determined according to the symbol probability.
  • obtaining the bit data corresponding to the constellation point, that is, the demodulated information outputted during the hard decision demodulation is a data bit, to send the data bit to the decoder.
  • the soft decision demodulation does not get the data bits, which converts the symbol probability into other forms of soft information (equivalent to a symbol decision with confidence), and sends the soft information to the decoder.
  • the coder uses these soft information to obtain data bits, that is, the soft decision demodulation output is soft information.
  • commonly used soft information has a signed probability form, a bit probability form, a likelihood ratio form, and a log likelihood ratio form, which can be mutually transformed; the following examples of the present invention are log likelihood ratios
  • the soft information form is taken as an example, but is not limited thereto, and can be implemented as needed during specific implementation. Perform conversions between different forms.
  • the processing is performed according to the following formula (2):
  • the transmission signal is a certain constellation point in the modulation constellation of the receiver, and is a constellation point corresponding to the transmission signal of the transmitter determined from the set of decision constellation points according to formula (2) .
  • the X in the judgment is equivalent to the set of constellation points, and all the constellation points in the set are selected to participate in the calculation according to the above formula (2), and the constellation points corresponding to the transmitted signals are determined therefrom, and the present embodiment is in the constellation diagram.
  • a set of all constellation points is taken as an example of a set of decision constellation points.
  • the meanings of the other symbols in equation (2) can be combined as described in equation (1).
  • the posterior probability of each constellation point in the set of determined constellation points ie, the symbol probability obtained in the formula (1)
  • the constellation point with the largest posterior probability is selected therefrom.
  • the constellation point corresponding to the transmitted signal As the constellation point corresponding to the transmitted signal.
  • the data bit corresponding to the constellation point is obtained, and the data bit is the data bit corresponding to the transmission signal, and the data bit is demodulated and outputted as a hard decision. Demodulate information.
  • the processing is performed according to the following formula; wherein, in this embodiment, the log likelihood of each bit in the data bits is solved.
  • L is the total number of bits in the data bits, and ⁇ is the number of constellation points in the modulation constellation.
  • the following formula (3) shows the conversion process from symbol probability to bit probability, each bit taking 0 and 1 (the data bits obtained by demodulation are actually a series of binary information sequences, this embodiment is in binary The probability of case) is:
  • the meaning of the above formula is that the selection of the constellation point set makes the bit 0.
  • the posterior probability of the constellation point ie, the symbol probability obtained by equation (1)
  • the maximum value is the probability that the bit is 0.
  • the maximum value of the posterior probability in the constellation point of the decision constellation point set that makes the bit 1 is the bit. The probability of being 1.
  • LLR ( ) represents the log likelihood ratio of the bit.
  • numerator and denominator is a form of multiple index summation. This kind of exponential participation calculation greatly increases the complexity of implementation. Therefore, in actual use, only the maximum value in the summation term can be taken, and the log likelihood ratio of each bit can be simplified as:
  • the soft decision demodulation obtains the log likelihood ratio information of the bit. If the soft decision demodulation is to obtain the "likelihood ratio", the In operation is removed in the formula (4). This information is output as soft information to the decoder, which is then processed by the decoder. That is, in soft decision demodulation, the probability of each bit in the data bit being 0 or 1 is calculated, and the log likelihood ratio of the bit is obtained based on the probability that the bit is 0 or 1. Specifically, determining a maximum symbol probability of the constellation point in the set of constellation points that makes the bit 0 is a probability that the bit is 0, and determining that the constellation point in the set of constellation points is such that the bit is 1 The maximum symbol probability is the probability that the bit is 1. For example, the constellation point that makes the bit 0 may be obtained by querying according to a mapping table of constellation point-data bits.
  • each star in the modulation constellation of the receiver The data bits corresponding to the coordinates have three bits. For example, the data bit corresponding to the constellation point A is "001", the data bit corresponding to the constellation point B is "100”, and the data bit corresponding to the constellation point C is "010".
  • the hard decision demodulation is to directly determine that the constellation point corresponding to the transmitted signal is the constellation point B, and obtain the data bit "100" corresponding to the constellation point B as the demodulation information output; and the soft decision demodulation is the known final data.
  • the log likelihood ratio of the first bit, the log likelihood ratio of the second bit, and the log likelihood ratio of the third bit are respectively calculated, and the decoder is subsequently used by the decoder.
  • the data bits are determined based on the log likelihood ratio information of each bit. Specifically, for example, for the first bit, by querying the mapping table, the constellation point with the bit 0 being the constellation point A and the constellation point C is selected, and then the maximum symbol probability of the two constellation points is selected as the first bit.
  • the soft information is taken as a log-likelihood ratio.
  • the soft information may be in other forms, for example, a likelihood ratio, etc., and those skilled in the art may convert between various forms. .
  • the symbol probability is calculated by using a simplified posterior probability, and demodulation is performed according to the symbol probability, thereby improving the anti-phase noise capability of the demodulation algorithm.
  • a set of all constellation points in the modulation constellation of the receiver is taken as an example of a set of decision constellation points.
  • only the modulation constellation is selected. Some of the constellation points in the calculation participate in the calculation, which can further improve the calculation efficiency.
  • the sector area, the square area, and the like are selected as an example, but those skilled in the art can understand that the specific implementation is not limited to the shape described below.
  • a circle, a diamond, or the like may also be used; when determining the shape of a region, generally, a distribution close to noise, a fan shape as shown in FIG. 7, or a calculation within a regular shape near the received signal may be selected.
  • a decision area may be determined in advance, and the set of constellation points in the decision area is the set of decision constellation points, and the constellation points located in the decision area are selected to participate in the calculation.
  • the constellation points in the decision area are all constellation points or partial constellation points in the constellation diagram. In this embodiment, some constellation points are taken as an example.
  • the method for determining the centralized decision area is described in detail below:
  • the received signal y also has a corresponding amplitude and phase angle, so that it also corresponds to a position in the constellation diagram.
  • the five-pointed star in the figure represents the corresponding position point of y in the constellation diagram. It can be seen that the received signal y does not coincide with the position of any one of the constellation points in the constellation due to the influence of noise during transmission. Demodulation is to identify which constellation point the received signal y should correspond to.
  • K n can be determined within the range described above and k e k n, and may be determined according to the following principles: Initial were taken and a small value in the range of, for example, compared to a loss of performance when compared with the embodiment Large, then increase the value of a certain step (such as 1) under the premise of complexity, until the performance meets the demand. The larger the sum of the sums, the more constellation points in the sector area ⁇ , the greater the complexity.
  • the ⁇ and "" of the sector region can be determined accordingly.
  • considers the influence of Gaussian noise on the received signal, and shifts the amplitude of the received signal at the corresponding position of the constellation diagram to the left and right, specifically along the The line connecting the position point and the origin of the constellation diagram and shifting left and right with the position point as the center, and the arc w1 and the arc line w2 are respectively obtained after the offset;
  • a is considering phase noise and Gaussian noise to receive The influence of the signal shifts the phase angle of the received signal at the corresponding position point to the left and right.
  • the connection between the position point and the origin of the constellation map is moved around the origin of the constellation diagram, and then the line segment w3 is obtained. And the line segment w4.
  • the w1, w2, w3, and w4 jointly determine a sector region; correspondingly, the determined constellation point set determined by the sector region ⁇ includes constellation points X1, ⁇ 2, ⁇ 3 ⁇ 8.
  • the above formula is different from the formula (2) in the first embodiment, only the decision region is different, and the decision region in the formula (2) is ', ⁇ r ", where X refers to the constellation All the constellation points; and the decision area in the formula (7) in this embodiment is ', ⁇ ⁇ , , where ⁇ is the sector area determined above, but only part of the constellation points in the constellation diagram.
  • demodulation Other formulas in the calculation can also change the decision area, which will not be described later.
  • FIG. 8 is a schematic diagram of a square decision region selected in another embodiment of the signal demodulation method according to the present invention. As shown in FIG. 8, the same position is represented by a five-pointed star in the constellation diagram; The area is a square area centered on the position point, and therefore, the square area Sy can be determined as long as the ⁇ shown in Fig. 8 is determined.
  • g is a number slightly larger than 1, such as 1.01, which is an adjustable parameter, and generally takes ⁇ 3; similarly, in the range of values, according to performance and complexity Contrast, determine the value that meets the system requirements.
  • the demodulation calculation can be performed according to the method described in the first embodiment, and only the decision area can be changed.
  • the constellation points participating in the calculation determined by the square decision area Sy in this embodiment include x1 to x16 shown in Fig. 8.
  • FIG. 9 is a schematic diagram of a square decision region selected in another embodiment of the signal demodulation method according to the present invention.
  • the constellation point is determined to be closest to the position point (shown by the five-pointed star) where the received signal y is located.
  • the n-layer constellation points surrounding it are used as a set of decision constellation points, that is, the decision area Ty shown in FIG.
  • the constellation point closest to the location point is xl.
  • the constellation point closest to the distance may be calculated by using a certain distance formula.
  • the selected one is A two-layer constellation point that surrounds the xl.
  • the signal demodulation method of the embodiment reduces the complexity of the demodulation algorithm, improves the processing efficiency, and improves the anti-phase noise by calculating the symbol probability by using the simplified posterior probability and demodulating according to the symbol probability. Capability; and by selecting a decision region that includes a portion of the constellation points, The computational complexity is further reduced and the computational efficiency is improved.
  • the apparatus is a receiver in a communication system, and may include: a parameter acquisition unit 91, a probability calculation unit 92, and a demodulation processing unit 93;
  • the parameter obtaining unit 91 is configured to acquire a received signal and a symbol probability parameter of the received signal, where the symbol probability parameter includes: a magnitude of the received signal, a phase angle, and a constellation point in the set of constellation points. Amplitude and phase angle, and standard deviation ⁇ of Gaussian noise and standard deviation of phase noise; the set of decision constellation points is located in a modulation constellation required to perform signal demodulation;
  • the probability calculation unit 92 is configured to calculate, according to the symbol probability parameter, a symbol probability with the received signal point ⁇ ;
  • the demodulation processing unit 93 is configured to perform demodulation according to the symbol probability, and output demodulation information, where the demodulation information corresponds to a data bit corresponding to the transmission signal.
  • the demodulation processing unit 93 includes: a seat decision subunit 931 and a bit map subunit 932.
  • the constellation decision subunit 931 is configured to determine that a constellation point with the highest symbol probability in the set of the determined constellation points is a constellation point corresponding to the sent signal, and a bit mapping subunit 932, configured to search for data corresponding to the constellation point.
  • Bit the data bit is a data bit corresponding to the transmission signal, and the data bit is output as demodulation information.
  • the demodulation processing unit is specifically configured to perform demodulation according to the symbol probability, and output soft information for generating data bits corresponding to the transmission signal,
  • the soft information includes a symbol probability, a bit probability, a likelihood ratio, or a log likelihood ratio; the soft information is the demodulation information.
  • the demodulation processing unit 93 includes: Bit probability subunit 933 and information processing subunit 934.
  • the bit probability sub-unit 933 is configured to determine a maximum symbol probability that is included in the constellation point of the set of constellation points in which the bit to be calculated is 0, and the probability that the bit to be calculated is 0, and determine the decision constellation.
  • an information processing sub-unit 934 configured to determine a probability that the bit to be calculated is 0, and Determining a probability that the calculated bit is 1 obtains a log likelihood ratio of the bit to be calculated, and outputs the log likelihood ratio as the demodulation information; the bit to be calculated is in the set of the determined constellation points
  • the constellation point corresponds to a bit in the data bit.
  • the foregoing constellation decision subunit 931 and bit map subunit 932 (which may be referred to as a hard decision unit group), the bit probability subunit 933, and the information processing subunit 934 (which may be referred to as a soft decision unit group) may exist simultaneously.
  • the signal demodulating device only one of the unit groups may exist. In this embodiment, only two unit groups are displayed in one picture.
  • the signal demodulating apparatus of this embodiment may further include: a decision area determining unit 94, configured to determine, after the acquiring the symbol probability parameter, a decision area in the constellation diagram, where The set of constellation points is the set of decision constellation points; each constellation point in the decision area is a part of constellation points in the constellation diagram.
  • a decision area determining unit 94 configured to determine, after the acquiring the symbol probability parameter, a decision area in the constellation diagram, where The set of constellation points is the set of decision constellation points; each constellation point in the decision area is a part of constellation points in the constellation diagram.
  • the signal demodulating device of this embodiment may be, for example, a digital signal processing unit of a receiver, or a word unit in the digital signal processing unit, or other application structure, as long as it relates to
  • the apparatus of the embodiment of the invention can be used for signal demodulation.
  • the signal demodulating device of this embodiment calculates the symbol probability by using a simplified posterior probability, and performs demodulation according to the symbol probability, thereby reducing the complexity of the demodulation algorithm, improving the processing efficiency, and improving the anti-phase noise. ability.
  • the aforementioned program can be stored in a computer readable storage medium.
  • the program when executed, performs the steps including the above-described method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

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Abstract

本发明提供一种信号解调方法和装置,其中,方法包括:获取符号概率参数,所述符号概率参数包括:接收信号的幅值ry和相角φy、判决星座点集合中的各星座点xj的幅值rxj和相角φxj、以及高斯噪声的标准差σn和相位噪声的标准差σθ;根据所述符号概率参数,计算发送信号为所述判决星座点集合中的各星座点xj的符号概率;根据所述符号概率进行解调,并输出解调信息。本发明提高了抗相位噪声的能力。

Description

信号解调方法和装置
技术领域
本发明涉及通信技术, 尤其涉及一种信号解调方法和装置。 背景技术
为了满足多媒体通信业务发展的需求, 现代无线通信系统广泛使用高阶 调制例如多进制正交幅度调制 ( Multiple Quadrature Amplitude Modulation, MQAM ) , 以使得在有限的频带上提供更高的信息传输速率。 但是, 高阶调 制对信号传输过程中的相位噪声、 高斯噪声等因素艮敏感, 这些噪声会使得 接收端的接收信号与正确的对应调制星座点相比产生随机移动或者旋转, 影 响接收端对接收信号所对应的发送信号的发送信号的判决, 有可能解调出错 误的调制星座点及对应的数据比特。
现有技术在解调处理时, 有的解调方法只考虑高斯噪声对接收信号的影 响, 不考虑相位噪声; 但是, 随着无线通信系统釆用调制的阶数越来越高, 星座点的密集程度增加, 相位噪声对解调的影响越来越显著, 如果不考虑相 位噪声将可能使得解调结果错误。 或者, 有的解调方法即使同时考虑高斯噪 声和相位噪声, 但是该现有解调算法的抗相位噪声能力较低, 当相位噪声较 大时, 相位噪声对解调结果的影响仍然较为显著。 发明内容 本发明实施例提供一种信号解调方法和装置, 以提高解调算法的抗相 位噪声的能力。
本发明实施例的第一个方面是提供一种信号解调方法, 包括: 获取接收信号以及所述接收信号的符号概率参数, 所述符号概率参数 包括:所述接收信号的幅值 ^和相角 ^、判决星座点集合中的各星座点 ^的 幅值 ^和相角 、 以及高斯噪声的标准差 "和相位噪声的标准差 ; 所述 判决星座点集合位于执行信号解调所需的调制星座图中;
根据所述符号概率参数, 计算与所述接收信号对应的发送信号为所述 判决星座点集合中的各星座点 ^的符号概率;
根据所述符号概率进行解调, 并输出解调信息, 所述解调信息与所述 发送信号对应的数据比特对应。
本发明实施例的另一个方面是提供一种信号解调装置, 包括: 参数获取单元, 用于获取接收信号以及所述接收信号的符号概率参 数, 所述符号概率参数包括: 接收信号的幅值 ^和相角 、 判决星座点集 合中的各星座点 的幅值 ^和相角 、 以及高斯噪声的标准差 "和相位噪 声的标准差 ; 所述判决星座点集合位于执行信号解调所需的调制星座图 中; '
概率计算单元, 用于根据所述符号概率参数, 计算与所述接收信号对 应的发送信号为所述判决星座点集合中的各星座点 ^的符号概率;
解调处理单元, 用于根据所述符号概率进行解调, 并输出解调信息, 所述解调信息与所述发送信号对应的数据比特对应。
本发明实施例提供的信号解调方法和装置, 通过釆用简化的同时存在 相位噪声和高斯白噪情况下的后验概率计算符号概率, 并根据该符号概率 进行解调, 提高了抗相位噪声的能力。 附图说明 图 1为本发明实施例信号解调方法应用的系统示意图;
图 2为本发明实施例信号解调方法所应用的双极化复用系统的结构示 意图;
图 3为本发明实施例信号解调方法所应用的 MIMO系统的结构示意 图;
图 4为本发明实施例信号解调方法所应用的双极化复用结合结合 MIMO系统的结构示意图;
图 5为本发明信号解调方法一实施例的流程示意图;
图 6为本发明信号解调方法一实施例的实验图表示意图;
图 7为本发明信号解调方法另一实施例中所选取的扇形判决区域示意图; 图 8为本发明信号解调方法又一实施例中所选取的方形判决区域示意图; 图 9为本发明信号解调方法再一实施例中所选取的方形判决区域示意图; 图 10为本发明信号解调装置实施例的结构示意图。 具体实施方式 首先对本发明实施例所述的信号解调方法和装置的应用环境进行介 绍:本发明实施例的信号解调方法应用到数字点对点微波、毫米波、 E-Band 传输系统, 移动蜂窝通信系统, 无线局域网系统, 无线城域网系统, 无线 个域网系统等通信系统中, 主要用于通信系统中的接收机, 对接收信号进 行处理。
一种可选的应用结构参见图 1所示, 图 1为本发明实施例信号解调方 法应用的系统示意图, 发射机的编码单元对要发送的信号进行编码后形成 信息序列, 数字信号处理单元进行信号调制, 即将信息序列变换为适合于 信道传输的信号, 然后经过数模转换器(Digital Anology Converter, 简称: DAC )的数模转换后由射频前端单元发射, 发送出去的信号可以称为发送 信号。 接收机的射频前端单元接收到的经过信道传输的信号可以称为接收 信号, 模数转换器 (Anology Digital Converter, 简称: ADC )对接收信号 进行模数转换后, 由数字信号处理单元解调, 即对经过信道传输中的噪声 影响的失真的数字信号进行恢复并得到信息序列供译码单元进行检错或 纠错。 其中, 接收机的数字信号处理单元釆用了本发明实施例提供的信号 解调方法。 本发明实施例的信号解调方法还可以应用于使用双极化复用和 交叉极化干扰消除 (Cross Polarization Interference Cancellation, 简称 XPIC) 技术的系统, 多输入多输出天线(Multiple Input Multiple Output, 简称: MIMO)系统以及双极化复用结合多输入多输出 MIMO等任何存在相位噪 声的系统, 上述的各系统可以分别参见图 2、 图 3和图 4, 图 2为本发明 实施例信号解调方法所应用的双极化复用系统的结构示意图, 图 3为本发 明实施例信号解调方法所应用的 MIMO系统的结构示意图,图 4为本发明 实施例信号解调方法所应用的双极化复用结合结合 MIMO系统的结构示 意图。
下面对本发明实施例的信号解调方法和装置进行详细说明:
实施例一
以下首先对本实施例中涉及到的几个概念进行说明: 所述的发送信号 指的是例如图 1中所述的发射机的数字信号处理单元生成的信号, 所述的 接收信号指的是例如图 1中所述的接收机的数字信号处理单元接收到的信 号, 所述的判决星座点集合指的是在接收机解调时所参照的调制星座图中 所选择的需要参与计算的多个星座点的集合。 而本实施例的信号解调方法 即是用于从判决星座点集合中识别出接收信号对应的是哪个星座点, 当识 别出该对应的星座点后, 就可以根据 "星座点-数据比特的映射表"得到该 星座点对应的数据比特, 该数据比特就是接收信息对应的数据比特, 也就 完成了接收信号的解调; 本领域技术人员可以理解, 在软判决(后续说明) 时解调输出的不是数据比特而是软信息, 后续可以根据该软信息得到对应 的数据比特。
图 5为本发明信号解调方法一实施例的流程示意图, 如图 5所示, 本 实施例的信号解调方法包括:
501、 获取接收信号以及所述接收信号的符号概率参数。
其中, 所述的接收信号即为前面所述的接收机的射频前端单元接收到 的经过信道传输的信号, 所述的符号概率参数是 502中用于计算符号概率 时所用到的参数, 可以包括: 接收信号的幅值 ^和相角 、 判决星座点集 合中的各星座点 的幅值 ^和相角 、 以及高斯噪声的标准差 "和相位噪 声的标准差 , 所述判决星座点集合位于执行信号解调所需的调制星座图 中。
502、 根据符号概率参数, 计算与所述接收信号对应的发送信号为所 述判决星座点集合中的各星座点的符号概率。
所述的与所述接收信号对应的发送信号指的是, 由发射机的射频前端 单元发射的信号, 该发送信号在经过信道传输后被接收机的射频前端单元 接收, 此时就称为接收信号。
本实施例中, 可以按照如下的公式 ( 1 ) 进行计算:
P pr n (丄、)
Figure imgf000006_0001
上述的公式 (1 ) , 所得到的符号概率是判决星座点集合中的各星座 点的后验概率, 本实施例的信号解调方法同时考虑了高斯噪声和相位噪声 对信号的影响, 并且在信号解调中对相位噪声的抗干扰能力也大大提高, 在相位噪声较大时具有更优的抗干扰能力。
503、 根据所述符号概率进行解调, 并输出解调信息, 所述解调信息 与所述发送信号对应的数据比特对应。
本步骤中, 所述的根据符号概率进行解调指的是, 根据公式 ( 1 ) 所 得到的判决星座点集合中的各星座点 ^的符号概率, 可以继续进行硬判决 解调或者软判决解调 (这两种解调方式后面详细说明) , 并向译码单元输 出判决后得到的解调信息。 所述的解调信息与发送信号对应的数据比特对 应, 可以包括两种情况, 一种情况是在硬判决解调时, 解调信息即为发送 信号对应的数据比特, 即直接输出数据比特; 另一种情况是在软判决解调 时, 解调信息即为用于生成发送信号对应的数据比特的软信息。
由于硬判决解调或者软判决解调的计算公式也是基于符号概率公式 ( 1 ) 的, 即是由符号概率公式变换得到, 而符号概率公式是经过化简的 公式, 所以, 相应的, 硬判决解调或者软判决解调时的计算相对于现有技 术的计算必然也大大降低了复杂度。
参见图 6, 图 6为本发明信号解调方法一实施例的实验图表示意图, 可以明显看出, 本实施例的信号解调方法与现有技术中的同时考虑高斯噪 声和相位噪声的信号解调方法相比, 计算的复杂度降低, 计算效率提高, 并且抗相位噪声的能力得到了显著的改善, 从而使得接收机能够快速的高 质量的解调出信号。 如图 6中所示, PN=0.08表示相位噪声方差为 0.08 , 且同等相位噪声强度下, 曲线越靠左, 性能越好。
以下对硬判决解调或者软判决解调分别进行说明: 根据输出的解调信 息的不同, 可将解调方式分成硬判决解调和软判决解调。
其中, 硬判决解调时会根据符号概率直接确定发送信号(此处的发送 信号即为本领域中常称为的发送符号, 本发明的实施例中将其称为发送信 号)对应的星座点, 并得到该星座点对应的比特数据, 即硬判决解调时输 出的解调信息为数据比特, 以将该数据比特送入译码器。
而软判决解调不会得到数据比特, 其是将符号概率转换为其他形式的 软信息(相当于一个带有置信度的码元判决), 并将该软信息送入译码器, 由译码器利用这些软信息得到数据比特, 即软判决解调输出的是软信息。 例如, 常用的软信息有符号概率形式、 比特概率形式、 似然比形式和对数 似然比形式, 它们之间均可以互相转化; 本发明的以下实施例中均是以对 数似然比的软信息形式为例, 但不局限于此, 在具体实施时可以根据需要 进行不同形式之间的转换。
具体的, 若本实施例的 503中釆用的解调方式为硬判决解调, 则依据 如下的公式 (2 ) 进行处理:
Figure imgf000008_0001
其中, 表示发送信号, 该发送信号是接收机的调制星座图中的某一 星座点, 是根据公式 (2 )从所述的判决星座点集合中确定的与发送机的 发送信号对应的星座点。 中的 X相当于判决星座点集合, 是选择该集 合中的所有星座点参与按照上述公式 (2 ) 的计算, 并从中确定与发送信 号对应的星座点的, 本实施例是以星座图中的所有星座点的集合作为判决 星座点集合为例。 公式 (2 ) 中的其他符号的含义可以结合参见公式 ( 1 ) 所述。
即, 在硬判决解调时, 是根据计算得到的判决星座点集合中的各个星 座点的后验概率 (即公式 ( 1 ) 中所得到的符号概率) , 从中选择后验概 率最大的星座点作为发送信号对应的星座点。 然后, 还会根据预先存储的 "星座点-数据比特的映射表"得到该星座点对应的数据比特,该数据比特 就是发送信号对应的数据比特, 并将该数据比特作为硬判决解调输出的解 调信息。
具体的, 若本实施例的 503中釆用的解调方式为软判决解调, 则依据 如下的公式进行处理; 其中, 本实施例是以求解数据比特中的每个比特的 对数似然比软信息为例, 并且以 = ^的调制模式为例, L为数据比特中 的总的比特数量, Μ为调制星座图中的星座点数量。 以下的公式 (3 )表 示的是从符号概率到比特概率的转换过程, 每个比特取 0和 1 (解调所得 到的数据比特实际上是一串二进制的信息序列, 本实施例以二进制为例) 的概率分别为:
Figure imgf000008_0002
上述公式所表示的意思是, 即选择判决星座点集合中使该比特为 0的 星座点中后验概率 (即公式 ( 1 )得到的符号概率) 最大值为该比特为 0 的概率, 选择判决星座点集合中使该比特为 1的星座点中后验概率最大值 为该比特为 1的概率。
由此得到每个比特的对数似然比信息为:
P(bk = 0 \ y)
LLR(bk) ^ In
Figure imgf000009_0001
其中, 表示某个比特, LLR ( )表示该比特的对数似然比。 公式 (4)中, 分子和分母的计算都是多项指数求和的形式, 这种有指数参与的计 算, 大大的增加了实现的复杂度。 因此, 实际使用时可以只取求和项中的 最大值, 这时每个比特的对数似然比可以简化为:
LLR(bk) ~ - Ην,,)
Figure imgf000009_0002
ln(v„)
(a - 0,1) ... (6)
Figure imgf000009_0003
至此, 软判决解调得到了该比特的对数似然比信息, 如果软判决解调 是得到 "似然比" , 则公式 (4 ) 中去掉 In运算。 并将该信息作为软信息 输出至译码器, 由译码器进行后续处理。 即, 软判决解调时, 是分别计算 数据比特中的各个比特的为 0或者 1的概率, 并根据上述比特为 0或者 1 的概率得到该比特的对数似然比。 具体的, 是确定判决星座点集合中的使 得该比特为 0的星座点中具有的最大符号概率作为该比特为 0的概率, 确 定判决星座点集合中的使得该比特为 1的星座点中具有的最大符号概率作 为该比特为 1的概率。 其中, 例如, 使得该比特为 0的星座点可以是根据 星座点 -数据比特的映射表查询得到。
举例说明: 假设根据某个调制模式, 接收机的调制星座图中的各个星 座点对应的数据比特都具有三个比特, 例如, 星座点 A对应的数据比特为 "001" , 星座点 B对应的数据比特为 " 100" , 星座点 C对应的数据比特 为 "010" 等, 硬判决解调是直接确定发送信号对应的星座点是星座点 B, 并得到该星座点 B对应的数据比特 " 100" 作为解调信息输出; 而软判决 解调是在已知最终的数据比特为三个比特的情况下, 分别计算第一个比特 的对数似然比、 第二个比特的对数似然比和第三个比特的对数似然比, 后 续会由译码器根据每个比特的对数似然比信息确定数据比特。 具体的, 例 如对于第一个比特, 通过查询映射表可知, 使得该比特为 0的星座点为星 座点 A和星座点 C,则选择该两个星座点中具有的最大符号概率为该第一 个比特为 0的概率, 例如, 星座点 A的符号概率为 pi , 星座点 C的符号 概率为 p2, 且 pl>p2, 则确定 pi为该第一个比特为 0的概率; 其他比特 概率的计算道理类似。
需要说明的是, 虽然本实施例上述的软判决解调计算是以 M = 2L的调 制模式为例, 但是其他调制模式也可以釆用上述的公式, 方法类似, 不再 赘述。 此外, 本实施例是以软信息为对数似然比为例, 具体实施中, 软信 息也可以是其他形式, 例如, 似然比等, 本领域技术人员可以在各种形式 间转换即可。
本实施例的信号解调方法, 通过釆用简化的后验概率计算符号概率, 并根据该符号概率进行解调, 提高了解调算法的抗相位噪声的能力。
实施例二
实施例一是以接收机的调制星座图中的所有星座点的集合作为判决 星座点集合为例, 本实施例中, 为了进一步降低解调算法的复杂度, 减少 计算量, 只选择调制星座图中的部分星座点参与计算, 能够进一步提高计 算效率。
以下的图 7-图 9所列举的几个实例中, 是以选择扇形区域、 方形区域 等为例进行说明, 但是本领域技术人员可以理解, 具体实施中并不局限于 如下所述的形状, 例如, 也可以使用圓形、 或者菱形等; 在确定区域形状 时, 通常可以考虑接近噪声的分布, 如图 7所示的扇形, 或者基于计算复 杂度的考虑选择接收信号附近一个规则形状内的星座点, 如图 8和图 9所 示的方形。 具体实施中,在获取符号概率参数之前,可以预先确定一个判决区域, 所述判决区域中的各星座点的集合为所述判决星座点集合, 位于该判决区 域内的星座点即为选择参与计算的星座点, 判决区域中的各星座点为星座 图中的所有星座点或者部分星座点, 本实施例以部分星座点为例。 下面详 细说明集中判决区域的确定方法:
图 7为本发明信号解调方法另一实施例中所选取的扇形判决区域示意 图, 如图 7所示, 接收信号 y也具有相应的幅度和相角, 所以其在星座图 中也对应一个位置, 以图 Ί中的五角星代表 y在星座图中的对应位置点, 可以看到, 由于在传输过程中受到噪声的影响, 该接收信号 y没有与星座 图中的任何一个星座点的位置重合, 解调就是要识别该接收信号 y应该与 哪个星座点对应。
本实施例中,可以选取图 7中的接收信号 y附近的扇形区域 Ω为判决 区域, 该扇形区域 Ω可以按照如下方法确定: 图 6中, ΔΓ = knan ·> a = keae。 和 为可调参数, 通常, 取 ≥^^ , ^ > ^- , g为略大于 1的数, 如 1.01 , d为星座点间的最小距离。 其中, ση、 d、 σθ、 g、 / 都是已知或 者预先确定的参数, 因此, 能够根据上述公式得到 和 的取值范围 。
可以在上述的 kn和 ke的取值范围内确定 kn和 , 可以按照以下原则确 定: 初始分别取 和 在取值范围的某个较小值, 若性能与实施例一相比 损失较大, 则在复杂度允许的前提下按一定步长 (如 1 )增大 和 的取 值, 直到性能满足需求。 通常 和 的值越大, 扇形区域 Ω中星座点越多, 复杂度会越大。
当确定了 和 之后, 可以据此确定扇形区域的 ΔΓ和"。 其中, ΔΓ是 考虑了高斯噪声对接收信号的影响, 将接收信号在星座图对应位置点的幅 度进行左右偏移, 具体是沿着所述位置点与星座图原点的连线且以所述位 置点为中心进行左右偏移, 偏移后分别得到了弧线 wl和弧线 w2; a是考 虑了相位噪声和高斯噪声对接收信号的影响, 将接收信号在对应位置点的 相角进行了左右偏移, 具体是将所述位置点与星座图原点的连线绕着星座 图原点左右各移动了 移动后分别得到了线段 w3和线段 w4。 如图 6所 示, 所述的 wl、 w2、 w3和 w4共同确定了扇形区域 ; 相应的, 该扇形 区域 Ω所确定的判决星座点集合中包括星座点 X 1、 χ2、 χ3 χ8。 在确定上述的扇形区域之后, 可以按照实施例一中所述的方法进行解 调计 判决解调公式为:
Figure imgf000012_0001
可以看出, 上述公式与实施例一中的公式 (2 )相比, 仅仅是判决区 域不同, 公式 (2 ) 中的判决区域是 '、ε r " , 其中的 X指的是星座图中 的所有星座点; 而本实施例中的公式 (7 ) 中的判决区域为 '、ε Ω , , 其 中的 Ω即为上述确定的扇形区域, 只是星座图中的部分星座点。 同理, 解 调计算中的其他公式也变换判决区域即可, 后续不再赘述。
图 8为本发明信号解调方法又一实施例中所选取的方形判决区域示意 图, 如图 8所示, 同理以五角星代表 y在星座图中的对应位置点; 本实施 例的方形判决区域是以所述的位置点为中心的正方形区域, 因此, 只要确 定了图 8中所示的 ΔΑ , 就可以确定该方形区域 Sy。
具体的, 所述的 可以按照如下方法确定: 图中 g为略大 于 1的数, 如 1.01 , 为可调参数, 通常取 ≥3; 同理, 在其取值范围内 根据性能和复杂度进行折中, 确定符合系统需求的数值。
同理, 在确定上述的方法区域之后, 可以按照实施例一中所述的方法 进行解调计算, 仅变换判决区域即可。 本实施例中的方形判决区域 Sy所 确定的参与计算的星座点包括图 8中所示的 xl〜xl 6。
图 9为本发明信号解调方法再一实施例中所选取的方形判决区域示意 图, 如图 9所示, 是确定与接收信号 y所在的位置点 (五角星所示)距离 最近的星座点及环绕其周围的 n层星座点作为判决星座点集合, 即图 9中 所示的判决区域 Ty。
如图 9所示, 与所述位置点距离最近的星座点为 xl , 在具体实施中, 可以是釆用某种距离公式计算得到该距离最近的星座点的; 本实施例中, 选择的是环绕该 xl的两层星座点。 其中, n为大于等于 1的整数, 通常取 n=2 , 同理, 在其取值范围内可根据性能和复杂度进行折中, 确定符合系 统需求的数值。
本实施例的信号解调方法, 通过釆用简化的后验概率计算符号概率, 并根据该符号概率进行解调,降低了解调算法的复杂度,提高了处理效率, 并提高了抗相位噪声的能力; 并且通过选取包括部分星座点的判决区域, 进一步降低了计算复杂度, 提高了计算效率。
实施例三
图 10为本发明信号解调装置实施例的结构示意图, 该装置可以执行 本发明任意实施例的信号解调方法, 本实施例简单描述该装置的结构, 其 具体的工作原理可以结合参见方法实施例所述。 如图 10所示, 该装置是 通信系统中的接收机, 可以包括: 参数获取单元 91、 概率计算单元 92和 解调处理单元 93 ; 其中,
参数获取单元 91 ,用于获取接收信号以及所述接收信号的符号概率参 数, 所述符号概率参数包括: 所述接收信号的幅值 ^ ^和相角 、 判决星座 点集合中的各星座点 的幅值 和相角 、 以及高斯噪声的标准差 σ"和相 位噪声的标准差 ; 所述判决星座点集合位于执行信号解调所需的调制星 座图中;
概率计算单元 92, 用于根据所述符号概率参数, 计算与所述接收信号 点 ^的符号概率; 例 , 其中, 所述
Figure imgf000013_0001
解调处理单元 93 ,用于根据所述符号概率进行解调,并输出解调信息, 所述解调信息与所述发送信号对应的数据比特对应。
可选的, 当釆用硬判决解调方式时, 所述解调处理单元 93包括: 星 座判决子单元 931和比特映射子单元 932。 其中, 星座判决子单元 931 , 用于确定所述判决星座点集合中的符号概率最大的星座点为所述发送信 号对应的星座点; 比特映射子单元 932 , 用于查找与星座点对应的数据比 特, 所述数据比特位所述发送信号对应的数据比特, 并将所述数据比特作 为解调信息输出。
可选的, 当釆用软判决解调方式时, 所述解调处理单元, 具体用于根 据所述符号概率进行解调, 并输出用于生成所述发送信号对应的数据比特 的软信息, 所述软信息包括符号概率、 比特概率、似然比或者对数似然比; 所述软信息为所述解调信息。
当所述软信息为似然比或者对数似然比时, 则解调处理单元 93包括: 比特概率子单元 933和信息处理子单元 934。 其中, 比特概率子单元 933 , 用于确定所述判决星座点集合中的待计算比特为 0的星座点中具有的最大 符号概率作为所述待计算比特为 0的概率, 并确定所述判决星座点集合中 的待计算比特为 1的星座点中具有的最大符号概率作为所述待计算比特为 1的概率; 信息处理子单元 934, 用于根据所述待计算比特为 0的概率、 以及所述待计算比特为 1的概率得到待计算比特的对数似然比, 并将所述 对数似然比作为所述解调信息输出; 所述待计算比特为与所述判决星座点 集合中的星座点对应的数据比特中的某个比特。
其中, 上述的星座判决子单元 931和比特映射子单元 932 (可以称为 硬判决单元组) 、 与比特概率子单元 933和信息处理子单元 934 (可以称 为软判决单元组) , 可以同时存在于该信号解调装置中, 也可以只存在其 中一个单元组, 本实施例只是将两个单元组均显示在一幅图中而已。
可选的, 本实施例的信号解调装置, 还可以包括: 判决区域确定单元 94, 用于在所述获取符号概率参数之后, 确定所述星座图中的判决区域, 所述判决区域中的各星座点的集合为所述判决星座点集合; 所述判决区域 中的各星座点为星座图中的部分星座点。
本领域技术人员可以理解, 本实施例的信号解调装置例如可以是接收 机的数字信号处理单元, 或者是该数字信号处理单元中的一个字单元, 或 者是其他的应用结构, 只要是涉及到信号解调的都可以釆用本发明实施例 的装置。
本实施例的信号解调装置, 通过釆用简化的后验概率计算符号概率, 并根据该符号概率进行解调,降低了解调算法的复杂度,提高了处理效率, 并提高了抗相位噪声的能力。
本领域普通技术人员可以理解: 实现上述各方法实施例的全部或部分 步骤可以通过程序指令相关的硬件来完成。 前述的程序可以存储于一计算 机可读取存储介质中。 该程序在执行时, 执行包括上述各方法实施例的步 骤; 而前述的存储介质包括: ROM、 RAM, 磁碟或者光盘等各种可以存 储程序代码的介质。

Claims

权 利 要 求 书
1、 一种信号解调方法, 其特征在于, 包括
获取接收信号以及所述接收信号的符号概率参数, 所述符号概率参数 包括:所述接收信号的幅值 和相角%、判决星座点集合中的各星座点 的 幅值 ^和相角 、 以及高斯噪声的标准差 "和相位噪声的标准差 ; 所述 判决星座点集合位于执行信号解调所需的调制星座图中;
根据所述符号概率参数, 计算与所述接收信号对应的发送信号为所述 判决星座点集合中的各星座点 ^的符号概率;
根据所述符号概率进行解调, 并输出解调信息, 所述解调信息与所述 发送信号对应的数据比特对应。
2、 根据权利要求 1所述的信号解调方法, 其特征在于, 所述根据所 述符号概率进行解调, 并输出解调信息, 包括:
确定所述判决星座点集合中的符号概率最大的星座点为所述发送信 号对应的星座点;
查找与所述星座点对应的数据比特, 所述数据比特为所述发送信号对 应的数据比特, 并输出所述数据比特;
相应的, 所述解调信息与所述发送信号对应的数据比特对应包括: 所 述解调信息为所述发送信号对应的数据比特。
3、 根据权利要求 1所述的信号解调方法, 其特征在于, 所述根据所 述符号概率进行解调, 并输出解调信息, 包括:
根据所述符号概率进行解调, 并输出软信息, 所述软信息包括符号概 率、 比特概率、 似然比或者对数似然比;
相应的, 所述解调信息与所述发送信号对应的数据比特对应包括: 所 述解调信息为用于生成所述发送信号对应的数据比特的软信息。
4、 根据权利要求 3所述的信号解调方法, 其特征在于, 若所述解调 信息为似然比或者对数似然比, 则所述根据所述符号概率进行解调, 并输 出解调信息, 包括:
确定所述判决星座点集合中的待计算比特为 0的星座点中具有的最大 符号概率作为所述待计算比特为 0的概率;
确定所述判决星座点集合中的待计算比特为 1的星座点中具有的最大 符号概率作为所述待计算比特为 1的概率;
根据所述待计算比特为 0的概率、 以及所述待计算比特为 1的概率得 到所述待计算比特的似然比或者对数似然比, 并将所述似然比或者对数似 然比作为所述解调信息输出;
所述待计算比特为与所述判决星座点集合中的星座点对应的数据比 特中的某个比特。
5、 根据权利要求 1所述的信号解调方法, 其特征在于, 在所述获取 符号概率参数之前, 还包括:
确定所述调制星座图中的判决区域, 所述判决区域中的各星座点的集 合为所述判决星座点集合; 并且, 所述判决区域中的各星座点为所述调制 星座图中的部分星座点。
6、 根据权利要求 5所述的信号解调方法, 其特征在于, 所述确定所 述星座图中的判决区域, 具体为:
确定包括所述接收信号在星座图中的对应位置点的扇形区域、 或者方 形区域为所述判决区域。
7、 根据权利要求 1-6任一所述的信号解调方法, 其特征在于, 所述计 算与所述接收信号对应的发送信号为所述判决星座点集合中的各星座点 ^的符号概率, 具体为:
-exp 其中, 所述
4πσ, 2σ 2
v. ^ rx ryaj + an 2 所述 (x = x / 为所述符号概率。
8、 一种信号解调装置, 其特征在于, 包括:
参数获取单元, 用于获取接收信号以及所述接收信号的符号概率参 数, 所述符号概率参数包括: 所述接收信号的幅值 ^ ^和相角 、 判决星座 点集合中的各星座点 的幅值 和相角 、 以及高斯噪声的标准差 σ"和相 位噪声的标准差 ; 所述判决星座点集合位于执行信号解调所需的调制星 座图中;
概率计算单元, 用于根据所述符号概率参数, 计算与所述接收信号对 应的发送信号为所述判决星座点集合中的各星座点 ^的符号概率;
解调处理单元, 用于根据所述符号概率进行解调, 并输出解调信息, 所述解调信息与所述发送信号对应的数据比特对应。
9、 根据权利要求 8所述的信号解调装置, 其特征在于, 所述解调处 理单元包括:
星座判决子单元, 用于确定所述判决星座点集合中的符号概率最大的 星座点为所述发送信号对应的星座点;
比特映射子单元, 用于查找与所述星座点对应的数据比特, 所述数据 比特位所述发送信号对应的数据比特, 并输出所述数据比特, 所述数据比 特为所述解调信息。
10、 根据权利要求 8所述的信号解调装置, 其特征在于,
所述解调处理单元, 具体用于根据所述符号概率进行解调, 并输出用 于生成所述发送信号对应的数据比特的软信息, 所述软信息包括符号概 率、 比特概率、 似然比或者对数似然比; 所述软信息为所述解调信息。
11、 根据权利要求 10所述的信号解调装置, 其特征在于, 所述解调 处理单元包括:
比特概率子单元, 用于确定所述判决星座点集合中的待计算比特为 0 的星座点中具有的最大符号概率作为所述待计算比特为 0的概率, 并确定 所述判决星座点集合中的待计算比特为 1的星座点中具有的最大符号概率 作为所述待计算比特为 1的概率;
信息处理子单元, 用于根据所述待计算比特为 0的概率、 以及所述待 计算比特为 1的概率得到所述待计算比特的似然比或者对数似然比, 并将 所述似然比或者对数似然比作为所述解调信息输出; 所述待计算比特为与 所述判决星座点集合中的星座点对应的数据比特中的某个比特。
12、 根据权利要求 8所述的信号解调装置, 其特征在于, 还包括: 判决区域确定单元, 用于确定所述调制星座图中的判决区域, 所述判 决区域中的各星座点的集合为所述判决星座点集合; 并且, 所述判决区域 中的各星座点为所述调制星座图中的部分星座点。
13、根据权利要求 8-12任一所述的信号解调装置, 其特征在于, 所述 概率计算单 具体用于根据如下公式计算所述符号概率: , 其中, 所述
Figure imgf000017_0001
σ] , 所述 (x = x / j )为所述符号概率
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