JP2006245700A - Receiving method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a receiving apparatus for receiving spread spectrum signals in which increase in throughput is suppressed. <P>SOLUTION: A hard deciding section 54 performs hard judgment of a plurality of chip signals. A correlation section 56 creates a plurality of combinations for one symbol while combining two out of the plurality of chip signals subjected to hard decision. While performing a plurality of kinds of rotation of one phase of one combination for a plurality of combinations, correlation processing with the other phase of one combination is performed thus performing correlation processing for the plurality of combinations while deriving a plurality of correlation values from one combination. Furthermore, the plurality of correlation values derived for the plurality of combinations are classified into a plurality of groups depending on the rotation. A determining section 58 determines the value of a phase signal, based on correlation values included in the plurality of groups, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reception technique, and more particularly, to a reception method and apparatus for receiving a spread spectrum signal.

As a spread spectrum communication system using a 2.4 GHz band radio frequency, a wireless LAN (Local Area Network) of the IEEE 802.11b standard has been put into practical use. The wireless LAN realizes a maximum transmission rate of 11 Mbps by CCK (Complementary Code Keying) modulation. In general, such a receiving apparatus corresponding to CCK modulation prepares a plurality of waveform patterns of a transmitted signal in advance, and demodulates a combination of signals corresponding to a waveform closest to the waveform of the received signal. (For example, refer to Patent Document 1). Such a spread spectrum method used in the wireless LAN of the IEEE802.11b standard is called a direct spread method (see, for example, Patent Document 1).
JP 2003-168999 A

  A receiving apparatus generally receives a CCK-modulated signal, performs FWT (Fast Walsh Transformation) operation on the received signal, and derives a plurality of correlation values. Further, the receiving apparatus selects a correlation value having the largest value from a plurality of correlation values, and reproduces a combination of signals corresponding to the selected correlation value. In order to increase the accuracy of the combination of signals reproduced in such processing, it is necessary to increase the number of bits to be used when calculating the correlation value. However, increasing the number of bits increases the processing amount of the receiving device. In addition, the processing amount when searching for the largest correlation value is large, and the processing amount of the receiving apparatus increases. Such an increase in processing amount increases the circuit scale of the receiving device and increases the power consumption of the receiving device. On the other hand, the accuracy of the combination of signals to be reproduced is desirably higher.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a reception technique that improves the quality of a received signal while suppressing an increase in processing amount.

  In order to solve the above problems, a receiving apparatus according to an aspect of the present invention receives a Walsh code of a plurality of chips formed by a combination of a plurality of phase signals as one symbol, and the receiving unit receives the received signal. For each phase of the Walsh codes of a plurality of chips, a phase correction unit that performs correction so as to approach the phase to be arranged, and a hard decision of the Walsh codes of the plurality of chips corrected by the phase correction unit Among the Walsh codes of a plurality of chips that have been hard-decided by the hard-decision unit, a combination generation unit that generates a plurality of combinations for one symbol while combining the two, and generated by the combination generation unit For a plurality of combinations, one of the combinations is rotated by a plurality of types while one of the combinations is rotated. Means for deriving a plurality of correlation values from one combination by executing correlation processing with the other, and performing correlation processing for a plurality of combinations; and a plurality of correlations derived for the plurality of combinations Based on the correlation values included in each of the plurality of groups classified in the correlation unit, and a correlation unit including means for classifying the values into a plurality of groups according to the amount of rotation, And a determining unit that determines a value of the corresponding phase signal. The combination generation unit generates a plurality of combinations for each of the plurality of phase signals, the correlation unit performs classification into a plurality of groups for each of the plurality of phase signals, and the determination unit includes: Each value of the plurality of phase signals is determined.

  The “phase to be arranged” corresponds to, for example, π / 4, 3π / 4, 5π / 4, and 7π / 4 in the case of QPSK, that is, corresponds to a phase where a signal is arranged on the transmission side.

  According to this aspect, the value of the phase signal is determined without using the Walsh code of a plurality of hard-decided chips and performing the FWT calculation as the processing target. Increase in the amount of processing can be suppressed.

  If the derived correlation value is not zero, the correlation unit fixes the correlation value to a predetermined value, and the determination unit detects a group that includes a large amount of the predetermined value from the plurality of groups. The value of the phase signal may be determined from the rotation amount corresponding to the group. In this case, an increase in processing amount can be suppressed. Further, if there is no group having all predetermined values, a group containing a large number of predetermined values is selected, so that the value of the phase signal can be determined.

  The correlation unit rotates one phase of one combination by 0 radians and π / 2 radians, derives a correlation value corresponding to each rotation amount, and with respect to the rotation amounts of 0 radians and π / 2 radians. By inverting the correlation value, a correlation value corresponding to the rotation amount of π radians and 3π / 2 radians may be derived. In this case, there are two types of rotation amounts, and no processing is required for rotation of 0 radians, and rotation of π / 2 radians can be realized by exchanging in-phase and quadrature components. Further, the correlation value corresponding to the rotation amounts of π radians and 3π / 2 radians is derived by simply inverting the correlation values corresponding to the rotation amounts of 0 radians and π / 2 radians. By the above processing, an increase in processing amount can be suppressed.

  Each of the absolute values of the Walsh codes of a plurality of chips corrected by the phase correction unit is compared with a threshold value. If the absolute value is smaller than the threshold value, zero is output, or the absolute value is equal to the threshold value. If it is more than the above, the comparison result is set so that the result of the comparison by the threshold value determination unit that outputs a predetermined value and the threshold value determination unit corresponds to a plurality of correlation values derived by the correlation unit. You may further provide the table production | generation part which produces | generates the table by which the reliability corresponding to each of a some correlation value was shown by converting. The determination unit may select a correlation value with high reliability indicated by a table from the correlation values included in the plurality of groups, and may determine the value of the phase signal based on the selected correlation value. In this case, when determining the value of the phase signal, the correlation value whose high reliability is shown by the table is used, so that the quality of the received signal can be improved.

  The correlation value included in each of the plurality of groups classified in the correlation unit includes the values of the in-phase component and the quadrature component, and the table generated in the table generation unit includes each of the in-phase component and the quadrature component of the correlation value. May show reliability. In this case, since the reliability is shown for each of the in-phase component and the quadrature component of the correlation value, the processing accuracy can be improved and the quality of the received signal can be improved.

  Detects in-phase and quadrature components with high reliability shown by the table among the in-phase and quadrature components of the correlation values included in each group while reflecting the result determined by the decision unit Then, a detection unit that detects a component corresponding to the detected component as a part to be corrected, and a plurality of chips that are hard-decided by the hard-decision unit based on the part that should be corrected detected by the detection unit A correction unit that corrects the Walsh code may be further included. The combination generation unit, the correlation unit, and the determination unit may repeatedly execute the process on the Walsh codes of a plurality of chips corrected by the correction unit. In this case, since the value of the phase signal is determined after correcting the Walsh codes of a plurality of chips based on the determined result, the quality of the received signal can be improved.

  Based on the result determined by the determination unit and the correlation values included in each of the plurality of groups, the table generator generates a table for the first correction unit that corrects the table and the table corrected by the first correction unit. And performing a logical OR operation between the result of the inverse conversion and the result of the comparison by the threshold value determination unit. You may further provide the 2nd correction part which corrects a result. The table generation unit and the determination unit may repeatedly execute the processing while using the comparison result corrected by the second correction unit. In this case, since the value of the phase signal is determined after correcting the comparison result based on the determined result, the quality of the received signal can be improved.

  Another aspect of the present invention is a reception method. The method should be arranged for receiving a plurality of chip Walsh codes formed by a combination of a plurality of phase signals as one symbol, and for each phase of the received plurality of chip Walsh codes. A step of performing correction so as to approach the phase, a step of hard-decision of the Walsh codes of the plurality of corrected chips, and a combination of two of the Walsh codes of the plurality of hard-decided chips are combined into one symbol. A step of generating a plurality of combinations, and a correlation process with the other of the one combination while rotating one of the phases of the plurality of combinations for a plurality of types. By deriving multiple correlation values from one combination, the correlation process can be applied to multiple combinations. And classifying the plurality of correlation values derived for the plurality of combinations into a plurality of groups according to the rotation amount, and based on the correlation values included in each of the plurality of classified groups Determining a value of a phase signal corresponding to the combination in the step of generating a plurality of combinations. The step of generating a plurality of combinations generates a plurality of combinations for each of the plurality of phase signals, and the step of classifying performs a classification into a plurality of groups for each of the plurality of phase signals. The determining step determines each value of the plurality of phase signals.

  The classifying step fixes the correlation value to a predetermined value if the derived correlation value is not zero, and the step of determining detects a group that includes a large number of the predetermined value among a plurality of groups. The value of the phase signal may be determined from the rotation amount corresponding to the detected group. The classifying step involves rotating one phase of one combination by 0 radians and π / 2 radians, deriving correlation values corresponding to the respective rotation amounts, and rotating amounts of 0 radians and π / 2 radians. The correlation value corresponding to the rotation amount of π radians and 3π / 2 radians may be derived by inverting the correlation value with respect to. Each of the absolute values of the Walsh codes of the plurality of chips corrected by the step of executing correction is compared with a threshold value, and if the absolute value is smaller than the threshold value, zero is output or the absolute value is decreased. If the threshold value is not less than the threshold value, the comparison result is converted so that the comparison result in the output step and the comparison result in the output step corresponds to a plurality of correlation values derived in the classification step. Generating a table showing reliability corresponding to each of the plurality of correlation values, and the step of determining shows the high reliability of the table from the correlation values included in the plurality of groups. The selected correlation value may be selected, and the phase signal value may be determined based on the selected correlation value.

  The correlation value included in each of the plurality of groups classified in the classification step includes in-phase component and quadrature component values, and the table generated in the table generation step is orthogonal to the in-phase component of the correlation value. Reliability may be shown for each of the components. While reflecting the result determined by the determining step, out of the in-phase component and the quadrature component of the correlation value included in each of the plurality of groups, either the in-phase component or the quadrature component that is highly reliable by the table is displayed. Detecting a component corresponding to the detected component as a portion to be corrected, and detecting the Walsh codes of a plurality of hard-decided chips based on the portion to be corrected detected in the detecting step. A step of generating a combination, a step of classifying, and a step of determining may be repeatedly performed on the modified Walsh codes of a plurality of chips. In the step of correcting the table based on the result determined in the step of determining and the correlation values included in each of the plurality of groups, and in the step of generating the table with respect to the table corrected in the step of correcting A step of generating a table, further comprising the step of correcting the result of the comparison by executing a logical sum operation between the result of the inverse conversion and the result of the comparison, and performing a reverse conversion and a conversion result In the determining step, the process may be repeatedly executed using the comparison result corrected in the step of correcting the comparison result.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to improve the quality of a received signal while suppressing an increase in processing amount.

  Before describing the present invention in detail, an outline will be described. Embodiments described herein relate generally to a receiving device of a wireless LAN system. The receiving apparatus according to the present embodiment receives a CCK modulated signal. Therefore, the IEEE802.11b standard or the like is assumed for the wireless LAN system. In the CCK modulated signal, signals from a plurality of chips form one symbol. Each of the signals of the plurality of chips is generated by a combination of phase signals. Conventional receivers perform FWT operations on CCK-modulated signals to derive a plurality of correlation values. Furthermore, the receiving apparatus selects the maximum correlation value from the plurality of correlation values, and derives a combination of phase signals corresponding to the selected correlation value. At this time, if each of the signals of the plurality of chips uses a plurality of bits, the processing amount in the FWT calculation increases. Further, the processing amount has been increased in order to select the maximum correlation value. The receiving apparatus according to the present embodiment executes the following processing in order to reduce the processing amount.

  The receiving device corrects the phase of the received signal. That is, the phase is corrected so as to approach the phase where the received signal is to be arranged. The receiving apparatus makes a hard decision on the in-phase component and the quadrature component of the signal whose phase is corrected. Hereinafter, for the sake of clarity, the description will be made in units of one symbol. Here, the result of the hard decision with respect to one symbol is summarized as “IQtable0” (FIG. 4B described later). In addition, a plurality of combinations are generated for one symbol while combining two of the signals of the plurality of chips included in one symbol.

  Further, a plurality of correlation values are calculated between one combination and the other in one combination while rotating one of the combinations by “0 radians” and “π / 2 radians”. Here, a group is defined according to the rotation amount. For example, “Group 1” corresponding to “0 radians” and “Group 2” corresponding to “π / 2 radians” are defined. Each group includes a plurality of correlation values. Such processing is executed for each of the plurality of phase signals included in the signals of the plurality of chips. That is, the correlation value is calculated while changing the combination in one symbol according to the phase signal. This result is summarized as “FWTtable0” (FIGS. 5 and 6A described later), and among “FWTtable0”, a value that is not “0” is set to “1”, and “FWTtable1” (described later) This is summarized as FIG.

  On the other hand, the receiving apparatus compares the absolute value of the in-phase component of the signal whose phase has been corrected with a threshold value, and determines “1” if it is equal to or greater than the threshold value, and “0” if it is smaller than the threshold value. . Similar processing is also performed on the absolute value of the orthogonal component of the signal whose phase is corrected. Finally, the comparison result for one symbol is summarized as “IQtable1” (FIG. 4C described later). Further, based on the same combination and rotation amount as in the process of converting “IQtable0” to “FWTtable0”, a logical product is executed on “IQtable1” to obtain “MSKtable1” (FIG. 7 described later). Is generated. “MSKtable1” includes values of “0” and “1”. The “1” portion of “MSKtable1” indicates that the reliability of the value in “FWTtable1” corresponding to this is high.

  The receiving apparatus extracts a value corresponding to “1” of “MSKtable1” from “FWTtable1”. In the receiving apparatus, as a result of extraction, a group in which all the values included in one group are “1” is selected. Here, a search for a pattern of values included in the group is executed. If all the values included in one group are “1”, this corresponds to a large correlation value as in the FWT conversion. As a result, this corresponds to a probable amount of phase rotation corresponding to the group. Note that these selections are performed for each of the plurality of phase signals. Finally, the value of the phase signal is identified from the group thus selected. In the above processing, the receiving apparatus uses a hard-decision value.

  As an assumption of this embodiment, an outline of CCK modulation in the IEEE 802.11b standard will be described. In CCK modulation, 8 bits are defined as one unit (hereinafter, this unit is referred to as “symbol”), and these 8 bits are named d1, d2,. Of the symbols, the lower 6 bits are classified as [d3, d4], [d5, d6], [d7, d8], and each classified is mapped to the signal point arrangement of QPSK. The mapped phases are (φ2, φ3, φ4), respectively. Further, eight types of spreading codes P1 to P8 are generated from the phases φ2, φ3, and φ4 as follows.

一方、ひとつのシンボルのうち、上位２ビットの［ｄ１，ｄ２］は、ＤＱＰＳＫ（Ｄｉｆｆｅｒｅｎｔｉａｌ ｅｎｃｏｄｉｎｇ Ｑｕａｄｒａｔｕｒｅ Ｐｈａｓｅ Ｓｈｉｆｔ Ｋｅｙｉｎｇ）の信号点配置にマッピングされ、ここではマッピングした位相をφ１とする。さらに、φ１と拡散符号Ｐ１からＰ８より、以下の通り８通りのチップ信号Ｘ０からＸ７を生成する。

On the other hand, the upper 2 bits [d1, d2] of one symbol are mapped to a signal point arrangement of DQPSK (Differential Encoding Quadrature Shift Shift Keying), and the mapped phase is φ1 here. Further, eight chip signals X0 to X7 are generated from φ1 and spreading codes P1 to P8 as follows.

送信装置は、チップ信号Ｘ０からＸ７の順に送信する（以下、チップ信号Ｘ０からＸ７によって構成される時系列の単位も「シンボル」という）。なお、ＩＥＥＥ８０２．１１ｂ規格ではＣＣＫ変調の他に、ＤＢＰＳＫやＤＱＰＳＫの位相変調した信号が既知の拡散符号によって拡散されるが、ここでは、説明を明瞭にするためにこれらの説明を省略する。

The transmitting apparatus transmits in order of chip signals X0 to X7 (hereinafter, a time-series unit constituted by chip signals X0 to X7 is also referred to as “symbol”). In the IEEE802.11b standard, in addition to CCK modulation, a DBPSK or DQPSK phase-modulated signal is spread by a known spreading code. However, the description thereof is omitted here for the sake of clarity.

  FIG. 1 shows a burst format of a communication system according to an embodiment of the present invention. This burst format corresponds to the ShortPLCP of the IEEE802.11b standard. As shown in the figure, the burst signal includes a preamble, a header, and a data area. Further, the preamble is specified at a transmission rate of 1 Mbps by the DBPSK modulation method, the header is specified at a transmission rate of 2 Mbps by the DQPSK modulation method, and the data is specified at a transmission rate of 11 Mbps by the CCK modulation method. The preamble includes 56-bit SYNC and 16-bit SFD, and the header includes 8-bit SIGNAL, 8-bit SERVICE, 16-bit LENGTH, and 16-bit CRC. On the other hand, the length of the PSDU corresponding to the data is variable. Among the above burst formats, in the present embodiment, a signal subjected to CCK modulation is a processing target, and therefore processing for data will be described.

  FIG. 2 shows a configuration of the communication system 100 according to the embodiment of the present invention. The communication system 100 includes a reception device 10 and a transmission device 12. Furthermore, the receiving device 10 includes a receiving antenna 14, a radio unit 18, an orthogonal detection unit 20, an AGC (Automatic Gain Controller) 22, an AD conversion unit 24, a baseband processing unit 26, and a control unit 28. , A transmission antenna 16, a radio unit 30, and a modulation unit 32. In addition, a digital reception signal 200 and an output signal 202 are included as signals.

  The modulation unit 32 performs CCK modulation on information to be transmitted. Here, the information to be transmitted is indicated as d1, d2,... D8 as described above. The modulation unit 32 outputs a CCK modulated signal as a baseband signal. The radio unit 30 converts the baseband signal from the modulation unit 32 to a radio frequency signal. The radio unit 30 amplifies radio frequency signals. The transmitting antenna 16 transmits a radio frequency signal from the radio unit 30.

  The receiving antenna 14 receives a radio frequency signal. The radio unit 18 converts the received radio frequency signal into an intermediate frequency signal. The quadrature detection unit 20 performs quadrature detection on the intermediate frequency signal and outputs a baseband signal. In general, a baseband signal is represented by two components, an in-phase component and a quadrature component, which are collectively shown here. The AGC 22 amplifies the baseband signal while automatically controlling the gain in order to make the amplitude of the baseband signal within the dynamic range of the AD converter 24. The AD conversion unit 24 performs conversion from an analog signal to a digital signal for the baseband signal, and outputs a digital reception signal 200 composed of a plurality of bits. The baseband processing unit 26 demodulates the digital reception signal 200 and outputs an output signal 202. The control unit 28 controls the timing of the receiving device 10 and the like.

  FIG. 3 shows the configuration of the baseband processing unit 26. The baseband processing unit 26 includes a phase correction unit 50, an equalizer 52, a hard determination unit 54, a correlation unit 56, a determination unit 58, a threshold determination unit 60, a table generation unit 62, a detection unit 64, and a correction unit 66. Including.

  The digital reception signal 200 is input to the phase correction unit 50. The digital reception signal 200 corresponds to a signal that has been CCK modulated by the transmission device 12 (not shown), and can be said to be a Walsh code. The digital reception signal 200 is shown as the above-described chip signal. Therefore, one chip signal is formed by a combination of φ1 to φ4. Here, all of φ1 to φ4, or any of these are called “phase signals”. The phase correction unit 50 corrects each phase of the plurality of chip signals so as to approach the phase to be arranged. Here, the “phase to be arranged” is a phase in which a chip signal may be arranged. Since the chip signal is arranged at the signal point of QPSK, the “phase to be arranged” corresponds to π / 4, 3π / 4, 5π / 4, and 7π / 4. For this reason, the phase correction unit 50 performs processing such that the phase of the chip signal approaches one of these phases. Since this process may be performed by a known technique, a description thereof will be omitted. Note that feedback processing may be performed, or feedforward processing may be performed.

  The equalizer 52 removes the influence of the multipath transmission path from the signal from the phase correction unit 50. The equalizer 52 is configured by a transversal type filter. Note that a configuration in which a DFE (Decision Feedback Equalizer) is added to a transversal filter may be used. In the processing subsequent to the equalizer 52, processing is performed in units of one symbol as described above. Therefore, this embodiment will be described with respect to one symbol. The chip signal output from the equalizer 52 is simply referred to as a chip signal.

  The hard decision unit 54 makes a hard decision for each of the plurality of chip signals. One symbol includes eight chip signals, and one chip signal includes an in-phase component and a quadrature component. Since the hard decision unit 54 makes a hard decision on each of the in-phase component and the quadrature component, it outputs eight hard decision results per symbol. Hereinafter, for the sake of clarity, it is assumed that the hard-decided chip signal is also simply referred to as a chip signal, and the chip signal includes an in-phase component and a quadrature component. The result of the hard decision corresponds to the aforementioned “IQtable0”.

  The correlation unit 56 generates a plurality of combinations for one symbol while combining two of the plurality of chip signals from the hard decision unit 54. Since eight chip signals are included for one symbol, four combinations are generated. The correlation unit 56 generates a plurality of combinations for each of the plurality of phase signals. That is, four combinations are generated for the phase signal “φ2”, four combinations are generated for the phase signal “φ3”, and four combinations are generated for the phase signal “φ4”. . Further, the combination will be specifically described as follows.

  “X0” and “X1”, “X2” and “X3”, “X4” and “X5”, “X6” and “X7” are combined with respect to the phase signal “φ2”. Further, “X0” and “X2”, “X1” and “X3”, “X4” and “X6”, “X5” and “X7” are combined with the phase signal “φ3”. Further, “X0” and “X4”, “X1” and “X5”, “X2” and “X6”, “X3” and “X7” are combined with the phase signal “φ4”. That is, a combination of a chip signal including a target phase signal and a chip signal not including the target phase signal and having the same phase signal other than the target phase signal is generated.

  The correlation unit 56 performs a correlation process with the other of the one combination while rotating a plurality of types of one phase of the one combination with respect to the plurality of generated combinations. For example, among “X0” and “X1”, “X1” is rotated by 0 radians or π / 2 radians. On the other hand, since “X1” is arranged at the signal point of QPSK, rotation of π radians and 3π / 2 radians should be performed. However, since the former is in a relationship in which 0 radians are inverted, and the latter is in a relationship in which π / 2 radians are inverted, the amount of rotation in the correlation unit 56 is obtained by utilizing these symmetries. It is limited to the two types described above. Note that the rotation of π / 2 radians is realized by inverting the in-phase component and the quadrature component. As a result, a plurality of correlation values are derived from one combination. For example, two correlation values are derived from a combination of “X0” and “X1”. Here, the correlation value is derived by adding the values of the two chip signals. Note that addition is performed for each of the in-phase component and the quadrature component.

  Further, the correlation process is executed for a plurality of combinations. As a result, eight correlation values are derived from the four combinations for one phase signal. Furthermore, the correlation unit 56 classifies the plurality of correlation values derived for the plurality of combinations into a plurality of groups according to the rotation amount. Here, the rotation amount “0 radians” is defined as “group 1”, and the rotation amount “π / 2 radians” is defined as “group 2”. Furthermore, “Group 1” includes four correlation values, and “Group 2” also includes four correlation values. Such classification into groups is performed for each of the plurality of phase signals. Note that the correlation value included in each of the plurality of groups classified by the correlation unit 56 includes the values of the in-phase component and the quadrature component. Note that the result of the above processing corresponds to the aforementioned “FWTtable0”.

  Furthermore, if the correlation value is not zero, the correlation unit 56 fixes the correlation value to a predetermined value, for example, “1”. The correlation unit 56 maintains the value as it is if the correlation value is zero. Such processing is executed for each of the in-phase component and the quadrature component of the correlation value. The result of the above processing corresponds to the above-mentioned “FWTtable1”. Since the value included in “FWTtable1” is “0” or “1”, each value can be expressed by 1 bit, and the data amount can be reduced. Note that the correlation unit 56 may directly generate “FWTtable1” without generating “FWTtable0”. In the processing of the correlator 56, the signed 2-bit “± 1” information is replaced with only the sign bit, so that it can be expressed by 1 bit. When the addition process of “X0” and “X1” is executed for such 1-bit information, “FWTtable1” is generated if the same / different codes are determined.

  The threshold determination unit 60 inputs each of the plurality of chip signals from the equalizer 52. The threshold value determination unit 60 compares the absolute value of the in-phase component of the chip signal with the threshold value for each of the plurality of chip signals, and further compares the absolute value of the quadrature component of the chip signal with the threshold value. . Further, the threshold value determination unit 60 outputs “0” if the absolute value is smaller than the threshold value, or sets the value to a predetermined value, for example, “1” if the absolute value is equal to or greater than the threshold value. Is output. The above result corresponds to the aforementioned “IQtable1”. “IQtable1” has 16 components.

  The table generation unit 62 converts the value included in “IQtable1” so that “IQtable1” corresponds to a plurality of correlation values in “FWTtable1” derived by the correlation unit 56. That is, the table generation unit 62 generates a plurality of combinations for the value of “IQtable1”, similarly to the correlation unit 56. Moreover, such a plurality of combinations are generated so as to correspond to each of the plurality of phase signals. Further, the same phase rotation as that of the correlation unit 56 is executed for a plurality of combinations. However, unlike the correlation unit 56, the table generation unit 62 calculates a logical product of the two values instead of the correlation process. As a result, a table having a value of “0” or “1” is generated while corresponding to each component of “FWTtable1”. Here, a value of “0” or “1” in the table indicates the reliability of each component of “FWTtable1”. That is, the component “FWTtable1” corresponding to “1” exhibits high reliability. Here, each component indicates an in-phase component and a quadrature component of the correlation value included in “FWTtable1”. The result of the above processing corresponds to the aforementioned “MSKtable1”.

  The determination unit 58 determines the value of the phase signal corresponding to the group based on the correlation value included in each of the plurality of groups in “FWTtable1”. “FWTtable1” includes two groups for one phase signal. Furthermore, a group corresponding to each of the three phase signals is included. One group corresponds to four combinations, and the correlation value corresponding to one combination has an in-phase component and a quadrature component. Therefore, one group has eight values. The determination unit 58 selects a value corresponding to a part corresponding to high reliability from eight values included in one group while referring to a part corresponding to the group in “MSKtable1”. Furthermore, the determination unit 58 determines which type the selected value corresponds to. Here, three types are defined in advance. “Type A” includes only the value “1”, “Type B” includes only the value “0”, and “Type C” includes “0” and “1”. Contains a value.

  The determination unit 58 detects a group other than a group including a predetermined value and zero among a plurality of groups while performing the following determination for each group. That is, groups corresponding to “type A” and “type B” are detected. Finally, the value of the phase signal is determined from the rotation amount corresponding to the detected group. For example, if the value selected from the group 1 of the phase signal “φ3” includes “0” and “1”, the group 1 of the phase signal “φ3” corresponds to “type C”. Further, if the value selected from the group 2 of the phase signal “φ3” includes only “0”, the group 2 of the phase signal “φ3” corresponds to “type B”. Of the above three types, the amount of rotation corresponding to “type A” is the value of the phase signal corresponding to it.

  This is because all of “Type A” have a value of “1”, which corresponds to a large correlation value. On the other hand, in “Type B”, all have a value of “0”, which corresponds to a small correlation value. Therefore, the rotation amount corresponding to “type A” or the rotation amount obtained by inverting the rotation amount corresponding to “type B” is the value of the phase signal. In the above example, the group 2 corresponds to “type B”. Since group 2 corresponds to “π / 2 radians”, “3π / 2 radians” obtained by inverting this becomes the value of the phase signal. Considering these, one of group 1 and group 2 is “type C”, and the other is “type A” or “type B”.

  The determination unit 58 determines each value of the plurality of phase signals while performing the above processing. In particular, the value of “φ4” is determined from the phase signals “φ2”. The value of the phase signal “φ1” is determined by delay detection. Since this is a known technique, description thereof is omitted here. Even with the above operation, the value of the phase signal may not be determined by the determination unit 58. For example, it is a case where the selected values of group 1 and group 2 are both “1”. As mentioned above, either group 1 or group 2 should be type C, but in the above case this cannot be determined. In order to deal with such a result, the baseband processing unit 26 further executes the following processing.

  The detection unit 64 reflects in-phase components or quadrature components of the correlation values included in each of the plurality of groups in “FWTtable1” while reflecting the group determined as a result of the determination by the determination unit 58, in particular. Among them, while detecting either the in-phase component or the quadrature component whose high reliability is indicated by “MSKtable1”, the corresponding portion is detected as a portion to be corrected. For example, when the reliability of the in-phase component with respect to one correlation value is high for the group determined as type C, the value of the in-phase component is “1”. Considering that the group is type C, the value of the quadrature component corresponding to the in-phase component should be “0”. However, if the value of the orthogonal component is “1”, the detection unit 64 detects this as a portion to be corrected. The detection unit 64 generates “ERRtable1” in the same format as “FWTtable1”. In “ERRtable1”, the part to be corrected is indicated as “1”, and the other part is indicated as “0”.

  The correcting unit 66 corrects the value included in “IQtable1” based on “ERRtable1”. Since “ERRtable1” and “FWTtable1” have the same format, the relationship between “IQtable1” and “FWTtable1” is also established between “IQtable1” and “ERRtable1”. The correction unit 66 corrects the value included in “IQtable1” so as not to cause contradiction in a plurality of combinations while considering a plurality of parts to be corrected. A specific example of this will be described later. Further, the correlation unit 56 and the determination unit 58 repeatedly execute the above-described processing for “IQtable1” corrected by the correction unit 66.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The operation of the receiving apparatus 10 having the above configuration will be described while showing the structure of data to be processed. 4A to 4C show the structure of data processed in the hard decision unit 54 and the threshold decision unit 60. FIG. FIG. 4A shows data output from the equalizer 52. As shown, a chip signal column 110, an I component column 112, and a Q component column 114 are included. The chip signal column 110 includes “X0” to “X7” described above. Therefore, the chip signal included in the chip signal column 110 corresponds to one symbol. The I component column 112 and the Q component column 114 indicate the values of the in-phase component and the quadrature component corresponding to the chip signal in decimal numbers.

  FIG. 4B shows data that is hard-determined by the hard-determination unit 54. FIG. 4B corresponds to “IQtable0” described above. The hard decision unit 54 decides “1” if the value of the in-phase component corresponding to the chip signal is 0 or more, and decides “−1” if it is smaller than 0. The same applies to the orthogonal component. FIG. 4C shows data determined by the threshold value determination unit 60 using the threshold value. FIG. 4C corresponds to the above-described “IQtable1”. Here, the absolute value of the in-phase component corresponding to the chip signal and the average value of the absolute values of the quadrature component are set as threshold values. If the absolute value is smaller than the threshold value, “0” is input, and if the absolute value is equal to or greater than the threshold value, “1” is input.

  FIG. 5 shows the structure of data processed in the correlation unit 56. FIG. 5 corresponds to “FWTtable0” described above. As shown, the combination signal column 116, the φ2 column 120, the φ3 column 122, and the φ4 column 124 are included. “F0” or the like shown in the combination signal column 116 corresponds to one combination. Further, “F0” to “F3” correspond to group 1, and “F4” to “F7” correspond to group 2. Further, “F8” to “F11” have an inverted relationship with Group 1 (hereinafter referred to as “Group 3”), and “F12” to “F15” have an inverted relationship with Group 2 (hereinafter referred to as “Group 3”). Group 4 ”). That is, the rotation amount in group 1 is “0 radians”, the rotation amount in group 2 is “π / 2 radians”, the rotation amount in group 3 is “π radians”, and the rotation amount in group 4 The amount of rotation is “3π / 2 radians”. Further, the φ2 column 120, the φ3 column 122, and the φ4 column 124 indicate the values of the respective phase signals.

  Here, for the phase signal “φ2”, “F0” corresponds to a combination of “X0” and “X1”, “F1” corresponds to a combination of “X2” and “X3”, “F2” corresponds to a combination of “X4” and “X5”, and “F3” corresponds to a combination of “X6” and “X7”. Furthermore, “F4” is the same as “F0”, “F5” is the same as “F1”, “F6” is the same as “F2”, and “F7” is “F3”. Are the same. For the phase signal “φ3”, “F0” corresponds to a combination of “X0” and “X2”, “F1” corresponds to a combination of “X1” and “X3”, and “ “F2” corresponds to a combination of “X4” and “X6”, and “F3” corresponds to a combination of “X5” and “X7”. Further, for the phase signal “φ4”, “F0” corresponds to a combination of “X0” and “X4”, “F1” corresponds to a combination of “X1” and “X5”, and “ “F2” corresponds to a combination of “X2” and “X6”, and “F3” corresponds to a combination of “X3” and “X7”.

  FIGS. 6A and 6B show the structure of data processed in the correlation unit 56 subsequent to FIG. FIG. 6A shows data obtained by extracting portions of group 1 and group 2 in FIG. FIG. 6B corresponds to data obtained by converting a value other than “0” into “1” among the data values included in FIG. FIG. 6B corresponds to “FWTtable1” described above. In FIG. 6A, since one value is a value from “2” to “−2”, 3 bits are required to express one value. On the other hand, in FIG. 6B, one value can be expressed by 1 bit.

  FIG. 7 shows the structure of data processed in the table generator 62. FIG. 7 corresponds to the aforementioned “MSKtable1”. “F0” and the like in the combination signal column 116 of FIG. 7 are generated by the same combination as in FIG. However, the correlation processing in FIG. 5 is a logical product operation in FIG. That is, the result of calculating the logical product from “X0” and “X1” of “IQtable1” for the phase signal “φ2” becomes the value at “F0” of “MSKtable1”. In “MSKtable1”, the portion indicated by the value “1” can be said to be a highly reliable portion.

  FIGS. 8A to 8J show the data structure of a pattern to be compared with the values included in the group in the determination unit 58. FIG. These patterns are used for comparison with “FWTtable1” described above. These figures correspond to one group in one phase signal. That is, the pattern should correspond to the in-phase component and the quadrature component for the four correlation values included in one group. 8A corresponds to type A, FIG. 8B corresponds to type B, and FIGS. 8C to 8J correspond to type C. FIG. These types are as described above.

  FIGS. 9A to 9C show the structure of data processed by the determination unit 58. FIG. FIG. 9A shows a result of associating “MSKtable1” in FIG. 7 with “FWTtable1” shown in FIG. In particular, the portion corresponding to the value “1” in “MSKtable1” is shown as a portion surrounded by a thick line (hereinafter referred to as “determination target area”) in “FWTtable1”. In the determination unit 58, the three types of types A, B, and C in FIGS. 8A to 8J are compared with the values of the determination target area to determine which type each group corresponds to. decide. FIG. 9B shows the result of comparison. For the phase signal “φ2”, both group 1 and group 2 have the possibility of type B or type C. For the phase signal “φ3”, group 1 is determined as type C, and group 2 has the possibility of type B or type C. The phase signal “φ4” is the same as the phase signal “φ3”. Here, as described above, since either group 1 or group 2 should be type A or type B, it is concluded that group 2 of phase signal “φ3” is type B. The phase signal “φ4” is the same as the phase signal “φ3”. The result thus concluded is shown in FIG. 9 (c).

  FIG. 10 shows the structure of data processed by the determination unit 58 subsequent to FIGS. 9A to 9C. FIG. 10 shows a data structure when the data shown in FIG. 9C is expanded into the group 3 and the group 4. Since group 2 of phase signal “φ3” is type B, group 4 of phase signal “φ3” is type A. The same applies to the phase signal “φ4”. Accordingly, the values of the phase signal “φ3” and the phase signal “φ4” are both determined to be “3π / 2”. The phase signal “φ2” is undefined in all groups.

  FIGS. 11A to 11C show the structure of data processed by the detection unit 64. FIG. FIG. 11A is the same as FIG. 9C, and it can be said that this is the result of the determination made in the determination unit 58. FIG. 11B is “FWTtable1” shown in FIG. From FIG. 11A, it is concluded that the group 1 of the phase signal “φ3” is type C. Therefore, either the in-phase component or the quadrature component in one correlation value should be “0”. For example, the reliability of the orthogonal component in “F1” of the phase signal “φ3” is high. The value of the orthogonal component is “1”. The value of the in-phase component corresponding to this should be “0”, but in “FWTtable1”, the value of this part is “1”. As a result, there is a possibility that the value of the part is incorrect. As described above, the detection unit 64 detects a portion that may be erroneous in “FWTtable1” while comparing the result of the determination made in the determination unit 58 with “FWTtable1”. FIG. 11C shows the detection result. This corresponds to the above-mentioned “ERRtable1”. “ERRtable1” has the same format as “FWTtable1”, and has a form corresponding to each other. It should be noted that the above-described erroneous portion is indicated by a value of “1” in “ERRtable1”.

  The correcting unit 66 corrects “IQtable0” in FIG. 4B based on the data in FIG. Therefore, the correction unit 66 identifies an erroneous part from the data in FIG. As illustrated, the in-phase component of “F1” in the phase signal “φ3” may be incorrect. Considering the combination for forming “F1”, it can be said that either the in-phase component of the chip signal “X1” or the in-phase component of the chip signal “X3” is incorrect. In addition, the orthogonal component of “F4” in the phase signal “φ3” may be incorrect. Considering the combination for forming “F4”, either the quadrature component of the chip signal “X1” or the in-phase component of the chip signal “X3” and the in-phase component of the chip signal “X0” or the chip signal “X2” It can be said that one of the orthogonal components is incorrect. The correction unit 66 executes the above-described process on the value portion of “1” in “ERRtable2”. As a result, the correction unit 66 determines to correct the in-phase component of the chip signal “X0” and the in-phase component of the chip signal “X3”.

  FIG. 12 shows the structure of data processed by the correction unit 66. FIG. 12 corresponds to the result of correcting “IQtable0” in FIG. The correction is performed by the correction unit 66. As described above, the in-phase component of the chip signal “X0” and the in-phase component of the chip signal “X3” are corrected.

  FIG. 13 shows the structure of data processed in the correlation unit 56. The correlation unit 56 performs the above-described correlation processing on the corrected “IQtable0” in FIG. FIG. 13 shows the result of correlation processing by the correlator 56. Since FIG. 13 has the same format as FIG. 6B, description thereof is omitted. FIG. 13 is referred to as “FWTtable3”.

  FIG. 14 shows the structure of data processed by the determination unit 58. FIG. 14 shows the final result in the determination unit 58. Further, the processing from “FWTtable3” in FIG. 13 to outputting the result in FIG. 4 is the same as the description so far, and the description is omitted. In FIG. 14, any type is specified for the group included in the phase signal “φ2”. In particular, since group 1 is identified as type B, group 3 is identified as type A. As a result, it is concluded that the phase signal “φ2” is “π radians”.

  FIG. 15 shows another configuration of the baseband processing unit 26. The baseband processing unit 26 includes a phase correction unit 50, an equalizer 52, a hard determination unit 54, a correlation unit 56, a determination unit 58, a threshold determination unit 60, a table generation unit 62, a first correction unit 68, and a second. A correction unit 70 is included. Compared with the baseband processing unit 26 of FIG. 3, the baseband processing unit 26 of FIG. 15 includes a first correction unit 68 and a second correction unit 70. In the following description, differences from the baseband processing unit 26 in FIG. 3 will be mainly described. Processing until the determination unit 58 determines the value of the first phase signal is the same as that in FIG. Therefore, these descriptions are omitted.

  The first correction unit 68 reflects the group determined as a result of the determination by the determination unit 58, in particular, among the correlation values included in each of the plurality of groups in “FWTtable1”. While detecting either the in-phase component or the quadrature component whose high reliability is indicated by “MSKtable1”, the corresponding portion is also detected. Further, the above-described “MSKtable1” is corrected so that the reliability of the corresponding part is increased. That is, if the value of the corresponding part is equal to the value to be specified by the determined type, the first correction unit 68 increases the reliability of the part. For example, when the value of the part is “1” when the type A is specified, the first correction unit 68 increases the reliability of the part. “MSKtable1” modified by the above processing is referred to as “MSKtable2”.

  The second correction unit 70 performs a conversion on “MSKtable2” that is the reverse of the conversion performed by the table generation unit 62. That is, “MSKtable2” is converted into data in chip signal units. At that time, conversion is performed in units of phase signals “φ2” to “φ4”. The result of converting “MSKtable2” is called “IQtable2”. Further, the second correction unit 70 derives a logical sum between “IQtable2” and “IQtable1”. Here, the logical sum operation is performed between the value included in “IQtable2” and the value included in “IQtable1”. For example, a logical sum is calculated between the in-phase components of “X0” included in the phase signals “φ2”, “φ3”, “φ4”, and “MSKtable1” of “IQtable2”. The above calculation corresponds to the correction of “IQtable1”. As a result, “IQtable3” having a value “1” increased from “IQtable1” is generated. The table generation unit 62 and the determination unit 58 repeatedly execute the above-described processing while using “IQtable3”.

  The operation of the receiving apparatus 10 having the above configuration will be described while showing the structure of data to be processed. Since it is as above-mentioned until FIG. 10, description is abbreviate | omitted. FIGS. 16A to 16C show the structure of data processed in the first correction unit 68. FIG. FIG. 16A is the same as FIG. 9C, and it can be said that this is the result of the determination made in the determination unit 58. FIG. 16B is “FWTtable1” shown in FIG. From FIG. 16A, it is concluded that group 1 of phase signal “φ3” is type C. Therefore, either the in-phase component or the quadrature component in one correlation value should be “0”. For example, the reliability of the orthogonal component in “F3” of the phase signal “φ3” in FIG. 16B is high. The value of the orthogonal component is “0”.

  The value of the in-phase component corresponding to this should be “1”, and the value of the portion in “FWTtable1” is also “1”. As a result, it can be said that the reliability of the part is high. In FIG. 16B, such a portion is surrounded by bold letters. As described above, the first correction unit 68 detects a portion that can be said to be highly reliable in “FWTtable1” while comparing the result of the determination made in the determination unit 58 with “FWTtable1”. The first correction unit 68 corrects “MSKtable1” according to the detected result. The result of the correction corresponds to the aforementioned “MSKtable2”. FIG. 16C shows “MSKtable2”. “MSKtable2” has the same format as “FWTtable1” and has a form corresponding to each other. In addition, a portion of “MSKtable2” modified from “MSKtable1” is surrounded by bold characters.

  FIG. 17 shows the structure of data processed in the second correction unit 70. FIG. 17 corresponds to “IQtable2” described above. As shown in the figure, the above-described conversion is performed in units of the phase signals “φ2”, “φ3”, and “φ4”. For example, in “MSKtable2”, the quadrature component of “F0” and “F4” of the phase signal “φ2” are related to the quadrature component of the chip signal “X0” in the phase signal “φ2” of “IQtable2”. . Therefore, the value of the quadrature component of the chip signal “X0” in the phase signal “φ2” in FIG. 17 is “2”. The processing as described above is performed on “MSKtable2”, and “IQtable2” in FIG. 17 is derived.

  18A to 18C show the structure of data processed in the second correction unit 70 subsequent to FIG. FIG. 18A shows “IQtable2” as in FIG. 17, but the value of “2” in FIG. 17 is converted to “1”. FIG. 18B shows “IQtable1”. As described above, the second correction unit 70 calculates a logical sum between “IQtable2” and “IQtable1”. FIG. 18C shows the logical sum operation result. This corresponds to the aforementioned “IQtable3”. Here, as described above, the logical sum is calculated for the corresponding portions of the φ2 column 120, the φ3 column 122, the φ4 column 124, and “IQtable1”. For example, the orthogonal component “X0” in the φ2 column 120 in FIG. 18A, the orthogonal component “X0” in the φ3 column 122, the orthogonal component “X0” in the φ4 column 124, “X0” in FIG. A logical sum is calculated for the orthogonal components. The calculation result in the above example is input to the orthogonal component “X0” in FIG.

  FIG. 19 shows the structure of data processed in the table generator 62. FIG. 19 corresponds to “MSKtable3” described above. Since the method for generating “MSKtable3” in FIG. 19 from “IQtable3” in FIG. 18C is as described above, description thereof is omitted. The table generation unit 62 outputs the generated “MSKtable3” to the determination unit 58 in FIG.

  According to the embodiment of the present invention, as a processing target, a plurality of hard-decided chip signals are used, and based on a value of “1” or “0” included in each of a plurality of groups, Since the value of the phase signal is determined, an increase in processing amount for determining the value of the phase signal can be suppressed. Further, since the FWT calculation is not used when determining the value of the phase signal, an increase in the processing amount can be suppressed. Further, since the process for determining the value of the phase signal is performed based on 1-bit data having a value of “1” or “0”, an increase in the processing amount can be suppressed. In addition, the circuit scale can be reduced. In addition, since an increase in processing amount can be suppressed, power consumption can also be reduced. In addition, since the power consumption can be reduced, the battery driving time can be extended. Further, in order to determine the value of the phase signal, a group other than the group including the values of “1” and “0” is detected, and the detection can be realized by pattern detection. Can be suppressed.

  Also, since pattern detection is performed, it is possible to avoid mounting a multiplier. Moreover, since there are two types of rotation amounts, an increase in the processing amount can be suppressed. Further, no processing is required for the rotation of 0 radians, and the rotation of π / 2 radians can be realized by exchanging the in-phase component and the quadrature component, so that an increase in processing amount can be suppressed. Further, since the correlation value showing high reliability is used when determining the value of the phase signal, the quality of the received signal can be improved. In addition, since the reliability is determined based on the amplitude of the received signal, an increase in the processing amount can be suppressed. Moreover, since the reliability is shown for each of the in-phase component and the quadrature component of the correlation value, the processing accuracy can be improved and the quality of the received signal can be improved.

  Further, since the value of the phase signal is determined after correcting a plurality of chip signals based on the determined result, the quality of the received signal can be improved. In addition, since the same processing as before is performed on the corrected chip signal, an increase in circuit scale can be suppressed. Further, since the value of the phase signal is determined after correcting “MSKtable1” based on the determined result, the quality of the received signal can be improved. Further, since the same processing as before is executed for the modified “MSKtable1”, an increase in circuit scale can be suppressed.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, if an indefinite portion exists in the value of the phase signal determined by the determination unit 58, the baseband processing unit 26 uses the detection unit 64, the first correction unit 68, etc. again, The value of the phase signal is determined. However, the present invention is not limited to this. For example, the determination unit 58 may determine any type based on the number of “0” and the number of “1” included in the group. According to this modification, the processing can be simplified and the processing period can be shortened. That is, the value of the phase signal may be derived.

  In the embodiment of the present invention, if an indefinite portion exists in the value of the phase signal determined by the determination unit 58, the baseband processing unit 26 uses the detection unit 64, the first correction unit 68, etc. again, The value of the phase signal is determined. However, the present invention is not limited to this. For example, the detection unit 64, the first correction unit 68, and the like may be used. That is, the correction process may be executed a plurality of times. Further, a predetermined period may be determined in advance, and the process may be repeatedly executed until the period expires. At that time, if the period is reached, as described above, the determination unit 58 may determine any type based on the number of “0” and the number of “1” included in the group. Further, after the processing by the detection unit 64 or the like is executed, the processing by the first correction unit 68 or the like may be executed, or vice versa. Furthermore, they may be executed in parallel. According to this modification, the quality of the received signal can be further improved. That is, the value of the phase signal may be derived.

  In the embodiment of the present invention, the correlation unit 56 generates “FWTtable1” by setting a value other than “0” in “FWTtable0” to “1”. However, the present invention is not limited to this, and “FWTtable0” may be used instead of “FWTtable1” in the subsequent processing. According to this modification, the conversion process can be omitted.

It is a figure which shows the burst format of the communication system which concerns on the Example of this invention. It is a figure which shows the structure of the communication system which concerns on the Example of this invention. It is a figure which shows the structure of the baseband process part of FIG. 4A to 4C are diagrams showing the structure of data processed in the hard decision unit and the threshold decision unit shown in FIG. It is a figure which shows the structure of the data processed in the correlation part of FIG. FIGS. 6A and 6B are diagrams illustrating the structure of data processed subsequent to FIG. 5 in the correlation unit of FIG. It is a figure which shows the structure of the data processed in the table production | generation part of FIG. FIGS. 8A to 8J are diagrams illustrating a data structure of a pattern to be compared with values included in a group in the determination unit of FIG. FIGS. 9A to 9C are diagrams illustrating the structure of data processed in the determination unit of FIG. FIG. 10 is a diagram illustrating a structure of data processed subsequent to FIGS. 9A to 9C in the determination unit of FIG. 3. 11A to 11C are diagrams illustrating the structure of data processed in the detection unit of FIG. It is a figure which shows the structure of the data processed in the correction part of FIG. It is a figure which shows the structure of the data processed in the correlation part of FIG. It is a figure which shows the structure of the data processed in the determination part of FIG. It is a figure which shows another structure of the baseband process part of FIG. FIGS. 16A to 16C are diagrams illustrating the structure of data processed in the first correction unit in FIG. It is a figure which shows the structure of the data processed in the 2nd correction part of FIG. FIGS. 18A to 18C are diagrams illustrating the structure of data processed subsequent to FIG. 17 in the second correction unit of FIG. 15. It is a figure which shows the structure of the data processed in the table production | generation part of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 receiving apparatus, 14 receiving antenna, 18 radio | wireless part, 20 orthogonal detection part, 22 AGC, 24 AD conversion part, 26 baseband process part, 28 control part, 50 phase correction part, 52 equalizer, 54 hard decision part 56 correlation unit, 58 determination unit, 60 threshold value determination unit, 62 table generation unit, 64 detection unit, 66 correction unit, 68 first correction unit, 70 second correction unit, 100 communication system.

Claims (8)

A receiving unit that receives a plurality of chips of Walsh codes formed by a combination of a plurality of phase signals as one symbol;
A phase correction unit that performs correction so as to approach the phase to be arranged for each phase of the Walsh codes of the plurality of chips received by the reception unit;
A hard decision unit that hard decides Walsh codes of a plurality of chips corrected by the phase correction unit;
A combination generation unit that generates a plurality of combinations for one symbol while combining two of Walsh codes of a plurality of chips subjected to a hard decision in the hard decision unit;
By executing a correlation process with the other of the one combination while rotating a plurality of types of one phase of one combination for the plurality of combinations generated in the combination generation unit, Means for performing correlation processing for a plurality of combinations while deriving a plurality of correlation values from one combination, and a plurality of correlation values derived for the plurality of combinations into a plurality of groups according to the rotation amount A correlation unit including means for classifying;
A determination unit that determines a value of a phase signal corresponding to a combination in the combination generation unit based on a correlation value included in each of a plurality of groups classified in the correlation unit;
The combination generation unit generates a plurality of combinations for each of a plurality of phase signals,
The correlator performs classification into a plurality of groups for each of the plurality of phase signals,
The determination unit determines a value of each of a plurality of phase signals. If the derived correlation value is not zero, the correlation unit fixes the correlation value to a predetermined value,
The determination unit detects a group containing a large number of predetermined values from the plurality of groups, and determines a value of a phase signal from a rotation amount corresponding to the detected group. The receiving device described in 1.   The correlation unit rotates one phase of one combination by 0 radians and π / 2 radians, derives a correlation value corresponding to each rotation amount, and rotates 0 radians and π / 2 radians. The receiving apparatus according to claim 1, wherein a correlation value corresponding to a rotation amount of π radians and 3π / 2 radians is derived by inverting a correlation value with respect to. Each of the absolute values of the Walsh codes of the plurality of chips corrected by the phase correction unit is compared with a threshold value. If the absolute value is smaller than the threshold value, zero is output or the absolute value is a threshold value. If the value is greater than or equal to the value, a threshold value determination unit that outputs a predetermined value;
The reliability corresponding to each of the plurality of correlation values is converted by converting the comparison result so that the comparison result in the threshold value determination unit corresponds to the plurality of correlation values derived in the correlation unit. And a table generation unit that generates a table indicated by
The determining unit selects a correlation value having high reliability indicated by a table from the correlation values included in the plurality of groups, and determines a value of the phase signal based on the selected correlation value. The receiving device according to claim 1, wherein the receiving device is characterized in that: The correlation value included in each of the plurality of groups classified in the correlation unit includes values of the in-phase component and the quadrature component,
The receiving apparatus according to claim 4, wherein the table generated by the table generating unit shows reliability for each of the in-phase component and the quadrature component of the correlation value. While reflecting the result determined by the determination unit, out of the in-phase component and the quadrature component of the correlation value included in each of the plurality of groups, either the in-phase component or the quadrature component for which high reliability is shown by the table. A detection unit that detects a component corresponding to the detected component as a portion to be corrected after detection;
A correction unit that corrects Walsh codes of a plurality of chips that are hard-decided by the hard-decision unit based on the portion to be corrected detected by the detection unit;
The receiving apparatus according to claim 5, wherein the combination generation unit, the correlation unit, and the determination unit repeatedly perform processing on the Walsh codes of a plurality of chips corrected by the correction unit. A first correction unit for correcting the table based on the results determined by the determination unit and the correlation values included in each of the plurality of groups;
For the table corrected in the first correction unit, the conversion opposite to the conversion in the table generation unit is executed, and between the result of the reverse conversion and the comparison result in the threshold value determination unit A second correction unit that corrects a result of the comparison in the threshold value determination unit by performing a logical sum operation;
The receiving apparatus according to claim 5, wherein the table generation unit and the determination unit repeatedly execute processing while using the comparison result corrected by the second correction unit. Receiving a plurality of chips of Walsh codes formed by a combination of a plurality of phase signals as one symbol;
Performing correction so as to approach the phase to be placed for each phase of the received Walsh codes of the plurality of chips;
Hard-decision of the corrected multiple-chip Walsh codes;
Generating a plurality of combinations for one symbol while combining two of the plurality of hard-decided chip Walsh codes;
A plurality of combinations are generated by executing correlation processing with the other of the one combination while rotating a plurality of types of one phase of the combination for the plurality of generated combinations. Performing correlation processing for a plurality of combinations while deriving the correlation values of the plurality of combinations, and classifying the plurality of correlation values derived for the plurality of combinations into a plurality of groups according to the amount of rotation;
Determining a phase signal value corresponding to a combination in the step of generating the plurality of combinations based on correlation values included in each of the plurality of classified groups,
The step of generating the plurality of combinations generates a plurality of combinations for each of the plurality of phase signals,
The classifying step performs classification into a plurality of groups for each of the plurality of phase signals,
The determination method includes determining each value of a plurality of phase signals.

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