JP2009188878A - Multipath detecting method and radio receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multipath detecting method and a radio receiver, which can considerably reduce the time required for processing detection of a plurality of peaks from electric power value data in a path search range to enable a high-speed multipath detection. <P>SOLUTION: Data of all electric power values in the path search range stored in a search range power value storing memory 1-1 is successively stored in each register of a peak detector 1-2. The peak detector 1-2 detects arrival of each peak by comparing power values near the peak including rise and fall portions of the peak of each path signal and stores the arrival timing and the electric power value of each detected peak successively in a detection result storing register 1-3. In that case, the electric power values already stored in the detection result storing register 1-3 are compared with the electric power values of the peaks detected on arrival by the peak detector 1-2, and the arrival timings and electric power values of a predetermined number of peaks are stored in descending order of electric power values starting from the largest value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multipath detection method and a radio receiver, and in particular, in the field of mobile communication and the like, a radio signal transmitted from a transmitter has a plurality of propagation times having different propagation times due to reflection of buildings, mountains, hills, and the like. The present invention relates to multipath detection for detecting the arrival timing of each path signal of multipath signals received at a plurality of timings via a propagation path.

  In mobile communication based on a CDMA (Code Division Multiple Access) system or an OFDM (Orthogonal Frequency Division Multiplexing) system, etc., a radio signal transmitted from a transmitter passes through a plurality of propagation paths, so that the propagation time is short on the receiver side. Are received as a plurality of different radio signals. A radio signal received through such a plurality of propagation paths is called a multipath signal, and the receiver side needs to perform reception processing in accordance with the arrival timing of each path signal of the multipath signal.

  Multipath detection measures the delay profile (arrival timing and power value of each of the direct wave and delayed wave) of the specified search range time width, and extracts a predetermined number of path signals in descending order of power value. However, when extracting the second and subsequent path signals after extracting the path signal having the first power value, the rising and falling portions near the peak of the already extracted path signal are detected. In order to prevent erroneous detection as other path signals, it is necessary to perform mask processing for excluding from the search range in which the next path signal is detected.

    FIG. 3 shows a specific example of multipath detection. (A) before the path detection, (b) after the first peak path detection, (c) after the second peak path detection, and (d) the third peak path. A mode of multipath detection after detection is shown. Before path detection, as shown in (a) of the figure, the power value of each measurement point within the specified path search range (indicated by a black circle in the figure) is measured, and the power value of this delay profile is searched. It is stored in the range power value storage memory.

  Here, as shown in FIG. 3B, after detecting the first peak having the largest power value, the power values at the measurement points at the rising and falling portions before and after the first peak are masked. If not excluded, the power value at the measurement point near the first peak is erroneously detected as the power value of the second peak. Therefore, the second peak is detected by excluding the shaded area in FIG. 3B as the mask area after the first peak detection.

  Similarly, after detecting the second peak as shown in FIG. 3 (c), the power values of the measurement points at the rising and falling portions before and after the second peak must be masked and excluded, The power value at the measurement point near the second peak is erroneously detected as the power value of the third peak. Therefore, the shaded area in FIG. 3C is excluded as the mask area after the first and second peaks are detected, and the third peak is detected.

  As shown in FIG. 3D, the next peak detection is performed while excluding the measurement points at the rising and falling portions before and after the first and second peaks in this manner as the mask range. Thus, the three peaks of the first, second, and third positions are detected as each path signal of the multipath signal.

  FIG. 4 shows a processing flow of conventional multipath detection. As shown in the figure, in the conventional multipath detection, the total power value data in the search range is read (4-1), the maximum value (peak) data is detected from it (4-2), and the peak The arrival timing is stored in the detection result storage register (4-3).

  Then, a mask process is performed to replace the power value data at the measurement points at the timings before and after the peak detected in the process flow of 4-2 (rising and falling parts) with “0” (4-4). Is written in the search range power value storage memory (4-5), the number of peak detections is added by one (4-6), and it is determined whether a predetermined number of peak detections have been completed (4-7). If the predetermined number is completed, the process is terminated. If the predetermined number is not completed, the process returns to the above-described process 4-1 and the same process is repeated.

  The configuration of a conventional multipath detector is shown in FIG. As shown in the figure, the conventional multipath detector includes a search range power value storage memory 5-1, a peak detection unit 5-2, a peak neighborhood mask unit 5-3, and a detection result storage register 5-4. . The search range power value storage memory 5-1 stores the total power value data of the search range, and the peak detector 5-2 reads the total power value data of the search range from the search range power value storage memory 5-1. The power value data of the maximum value (peak) is detected from among them.

  The peak vicinity mask unit 5-3 searches the mask data obtained by rewriting the power value data of the rising and falling portions of the maximum power value (peak) detected by the peak detecting unit 5-2 to “0”, and the search range power value Store in the storage memory 5-1. The detection result storage register 5-4 stores the arrival timing of the maximum power value (peak) detected by the peak detection unit 5-2 and the information of the power value data for the number of extracted paths.

  The peak detection unit 5-2 repeats the process of reading all power value data from the search range power value storage memory 5-1 and detecting the maximum value (peak) power value data for the number of peaks to be detected. The mask unit 5-3 replaces the power value data of the mask range before and after the peak detected by the peak detection unit 5-2 with “0” until the number of detected peaks reaches the designated number, and the search range power value storage memory 5 −1 is repeatedly stored.

Therefore, in the conventional multipath detection, in order to detect the peak for the designated number of peak detections,
The time required for detecting the maximum power (peak) from the total power value in the search range × the number of detected peaks is required.

Patent Document 1 listed below as a prior art document describes a multipath detection method for processing multipath detection at high speed, and the multipath detection method uses all data of delay profile data when detecting the first peak. When the maximum value search of the block is executed and the peak after the second place is detected, the maximum value search is performed again only for the data block in which the delay profile data is updated, and the maximum value information in the memory block is updated. Other data blocks (memory blocks) use the maximum value information retrieved in the first time, and reduce the number of peak detection cycles after the second place.
JP 2002-164815 A

  As described above, in the conventional multipath detection, when detecting a multipath signal from the search range, it is necessary to perform peak detection processing for the number of peak detections for all power value data in the search range. In addition, after performing one peak detection process and before performing the next peak detection process, masking is performed by replacing the power value data for the mask width before and after the peak detected in the previous detection process with “0”. Therefore, it is necessary to store the masked data again in the search range power value storage memory. This process needs to be performed for (number of peak detections−1) times except for the final peak detection process, and increases in proportion to the number of peak detections.

  The present invention significantly reduces the time required to detect a plurality of peaks from the power value data in the path search range, and enables multipath detection at higher speed than conventional multipath detection. .

  In order to solve the above-mentioned problem, this multipath detection is performed by sequentially inputting time-series power values at each measurement point of the delay profile, and in the vicinity of the peak including the rising and falling portions of the power value of each path signal. The arrival of the peak is detected by comparing the power values, the arrival timing and the power value of the detected peak are sequentially stored, the power value of the peak already stored, and the power value of the peak detected as the arrival of the peak, And the arrival timing and power value of a predetermined number of peaks in order from the largest power value.

  According to the present invention, the processing for detecting a plurality of peaks from the power data in the path search range can be performed by reading the power data in the path search range only once, which is extracted as compared with the conventional multipath detection. Multipath detection can be performed in a processing time that is 1 / number of paths.

  In the present invention, the conventional peak detection unit and the peak vicinity mask unit are replaced with a peak detection unit that detects the arrival of a peak from power value data corresponding to the mask width, and the detection result storage register is selected from the detected peaks. In this configuration, the upper predetermined number of peaks of the power value are selected and stored. As a result, multipath signals can be detected by reading power value data for one search range.

  The configuration and operation of the present invention will be described in detail below. FIG. 1 shows a configuration example of a multipath detector of the present invention. As shown in the figure, the multipath detector of the present invention includes a search range power value storage memory 1-1, a peak detection unit 1-2, and a detection result storage unit (register) 1-3. .

  The search range power value storage memory 1-1 stores all power value data of the path search range, and the storage amount is the address of the search range length W_search. The peak detection unit 1-2 includes W_mask registers that store power value data corresponding to the mask width W_mask. Note that the mask width W_mask is a portion in the vicinity of the peak including the rising and falling portions of the peak. The detection result storage unit (register) 1-3 includes a register that stores peak information (peak arrival timing and peak power value) for the number of detected peaks W_peak.

  When power value data is stored in up to half (W_mask / 2) of the registers corresponding to the mask width W_mask, the peak detector 1-2 can determine peak arrival by storing the next power value data. Therefore, the determination enable (EN) signal for activating the peak determination function is turned on ('1').

  Further, when power value data having a value lower than the power value data already stored in the register of the peak detector 1-2 is stored in the state where the determination enable (EN) signal is on ('1'), the peak It is determined that arrival has been detected, and the maximum power value data stored in the register of the peak detector 1-2 (usually, power value data stored in the register at the intermediate position W_mask / 2 of the mask width W_mask) The peak information (peak arrival timing and peak power value) is output to the detection result storage unit (register) 1-3. At this time, a clear signal for erasing data stored in each register of the peak detector 1-2 is turned on ('1').

  The detection result storage unit (register) 1-3 receives the peak information (peak arrival timing and peak power value) output from the peak detection unit 1-2 when the clear signal is turned on ('1'). Compared with the power value of the peak information that has already been stored, the peak information is rearranged in order from the largest, and a predetermined number of peak information is stored in each register.

  As an operation example, it is assumed that the power value data of the delay profile shown in FIG. 2A is stored in the search range power value storage memory 1-1. The numbers (1) to (11) in FIG. 2 (a) are numbers that are assigned to the path signals of the multipath signal in descending order of the power value.

  FIG. 2B shows an operation example in which three peak arrivals are detected based on the power value data of FIG. Here, as parameters in the description of the operation example, a search range length W_search = 11, a mask width W_mask = 3 (a width including a peak power value and a measurement point of one power value before and after that), a detected peak number W_peak = 3 To do.

  Hereinafter, the peak detection unit 1-2 and the detection result storage unit (register) 1− for each timing T1 to T11 for sequentially reading each power value data of the search range from the search range power value storage memory 1-1 one by one. 3 will be described. At each timing T1 to T11, delay profile power value data (9), (4), (7), (2), (1), (3), (8), (10), (11) , (5), (6) are stored in the peak detector 1-2 in this order.

  First, at the first timing T1, the peak detector 1-2 stores the power value data (9) from the search range power value storage memory 1-1, and the determination enable signal (EN) is turned off ('0). ') Since the clear signal is off (' 0 '), only shift processing is performed. The detection result storage register 1-3 does not process anything because the clear signal is off ('0').

  At the second timing T2, the peak detector 1-2 stores the power value data of (4) from the search range power value storage memory 1-1, and the center register (number 2) of the peak detector 1-2. Since the power value data is stored up to, the determination enable signal (EN) is turned on ('1'). However, since it is unknown whether the data stored in the center register (number 2) of the peak detector 1-2 is the maximum value, the clear signal is turned off ('0') and only shift processing is performed. Since the clear signal is off ('0'), the detection result storage register 1-3 does not process anything.

  At the third timing T3, the peak detector 1-2 stores the power value data of (7) from the search range power value storage memory 1-1, and the determination enable signal (EN) is turned on ('1'). In this state, it is detected that data with a value smaller than the stored data (4) in the central register (register number 2) is stored, and the stored data (4) in the central register (register number 2) is determined to be a peak. Then, the power value data (power value and timing) of (4) is moved to the detection result storage register 1-3.

  Then, the clear signal is turned on (“1”), the data stored in all the registers of the peak detector 1-2 is cleared, and the determination enable signal (EN) is turned off (“0”). The detection result storage register 1-3 stores the power value data (4) from the peak detection unit 1-2 in the first register.

  At the fourth timing T4, the peak detector 1-2 stores the power value data of (2) from the search range power value storage memory 1-1, and the determination enable signal (EN) is off ('0'). Since the clear signal is off ('0'), only shift processing is performed, and the detection result storage register 1-3 does not perform any processing.

  At the fifth timing T5, the peak detection unit 1-2 stores the power value data of (1) from the search range power value storage memory 1-1, and the center register (register number 2) of the peak detection unit 1-2. Since the power value data is stored up to (), the determination enable signal (EN) is turned on ('1'). However, since it is unknown whether the data stored in the central register is the maximum value, the clear signal remains off ('0'), only shift processing is performed, and the detection result storage register 1-3 does nothing.

  At the sixth timing T6, the peak detector 1-2 receives the power value data (3) from the search range power value storage memory 1-1, and the determination enable signal (EN) is on ('1'). When it is detected that the data stored in the central register (register number 2) is smaller than the stored data (1), the stored data (1) in the central register (register number 2) is peak. The power value data (power value and timing) of (1) is moved to the detection result storage register 1-3.

  Then, the clear signal is turned on (“1”), the data stored in all the registers of the peak detector 1-2 is cleared, and the determination enable signal (EN) is turned off (“0”). The detection result storage register 1-3 compares the power value data (1) from the peak detector 1-2 with the power value data (4) already stored, and compares the power value data (1). Since the power value data (1) is stored in the first register, the power value data (4) is moved to the second register.

  At the seventh timing T7, the peak detector 1-2 stores the power value data of (8) from the search range power value storage memory 1-1, and the determination enable signal (EN) is off ('0'). Since the clear signal is off ('0'), only the shift process is performed, and the detection result storage register 1-3 does not process anything.

  At the eighth timing T8, the peak detector 1-2 stores the power value data of (10) from the search range power value storage memory 1-1, and the center register (register number 2) of the peak detector 1-2. Since the power value data is stored up to (), the determination enable signal (EN) is turned on ('1'). At this time, it is detected that data (10) having a value smaller than the stored data (8) of the center register (register number 2) of the peak detector 1-2 is detected, and the center register (register number 2) is stored. It is determined that the data (8) is a peak, and the power value data (power value and timing) of (8) is moved to the detection result storage register 1-3.

  Then, the clear signal is turned on (“1”), the data stored in all the registers of the peak detector 1-2 is cleared, and the determination enable signal (EN) is turned off (“0”). In the detection result storage register 1-3, the power value data (8) from the peak detecting unit 1-2 is compared with the power value data (4) already stored in the second register, and the power value is compared. Since the data (4) is larger, the power value data (8) is stored in the third register.

  At the ninth timing T9, the peak detection unit 1-2 stores the power value data of (11) from the search range power value storage memory 1-1, and the determination enable signal (EN) is off ('0'). Since the clear signal = off ('0'), only shift processing is performed, and the detection result storage register 1-3 does nothing.

  At the tenth timing T10, the peak detector 1-2 stores the power value data of (5) from the search range power value storage memory 1-1, and the center register (register number 2) of the peak detector 1-2. Since the power value data is stored up to (), the determination enable signal (EN) is turned on ('1'). However, since it is unknown whether the storage data (11) of the central register is the maximum value, the clear signal remains off ('0'), only shift processing is performed, and the detection result storage register 1-3 does not process anything.

  At the eleventh timing T11, the peak detection unit 1-2 stores the power value data of (6) from the search range power value storage memory 1-1, and the determination enable signal (EN) is on ('1'). In this state, it is detected that data with a value smaller than the stored data (5) of the central register (register number 2) is stored, and the stored data (5) of the central register (register number 2) has a peak. The power value data (power value and timing) of (5) is moved to the detection result storage register 1-3.

  Then, the clear signal is turned on (“1”), the data stored in all the registers of the peak detector 1-2 is cleared, and the determination enable signal (EN) is turned off (“0”). In the detection result storage register 1-3, the power value data (5) from the peak detection unit 1-2 is compared with the power value data (8) already stored in the third-order register to determine the power value. Since the data (5) is larger, the power value data (8) is discarded, and the power value data (4) stored in the second register is compared with the power value data (4). Therefore, the power value data (5) is stored in the third register.

  In FIG. 2B, power value data that can be a peak is shaded. As described above, in the peak detection unit 1-2, when power value data is stored in a register up to half the mask width (W_mask) (W_mask / 2), it is possible to determine peak arrival by storing the next power value data. When the determination enable (EN) signal indicating the above is turned on ('1') and the determination enable (EN) signal is on ('1'), it is already stored in the register of the peak detector 1-2. When the power value data having a value lower than the measured power value data is stored, it is determined that the peak has arrived, and the maximum power value data stored in the register of the peak detecting unit 1-2 (the register at the intermediate position W_mask / 2) The peak information of the power value data stored in (1) is output to the detection result storage unit (register) 1-3, and at this time, the stored data in each register of the peak detection unit 1-2 is deleted. By a clear signal it was configured to be turned on ( '1') that, in an extremely simple structure, and, in one path search range power data reading, it is possible to detect the peak arrival of a predetermined number.

It is a figure which shows the structural example of the multipath detector of this invention. It is a figure which shows the operation example of the multipath detection of this invention. It is a figure which shows the specific example of a multipath detection. It is a figure which shows the processing flow of the conventional multipath detection. It is a figure which shows the structure of the conventional multipath detector.

Explanation of symbols

1-1 Search range power value storage memory 1-2 Peak detection unit 1-3 Detection result storage unit (register)

Claims (4)

In a multipath detection method of a radio receiver that measures a delay profile of a radio signal passing through a plurality of propagation paths and detects arrival timing of a multipath signal,
The time series power value of each measurement point of the delay profile is sequentially input, and the arrival of the peak is determined by comparing the power values in the vicinity of the peak including the rising and falling portions of the power value of each path signal. A peak detection step to detect;
The peak arrival timing and power value detected in the peak detection step are sequentially stored, and the peak power value already stored is compared with the peak power value detected as the peak arrival in the peak detection step. A detection result storage step for storing the arrival timing and power value of a predetermined number of peaks in order from the largest value;
A multipath detection method including: In a wireless receiver that measures the delay profile of a wireless signal that passes through multiple propagation paths and detects the arrival timing of a multipath signal,
The time series power value of each measurement point of the delay profile is sequentially input, and the arrival of the peak is determined by comparing the power values in the vicinity of the peak including the rising and falling portions of the power value of each path signal. A peak detector to detect;
The peak arrival timing and power value detected by the peak detection unit are sequentially stored, and the peak power value already stored is compared with the peak power value detected as peak arrival by the peak detection unit. A detection result storage unit for storing the arrival timing and power value of a predetermined number of peaks in order from the largest value;
With wireless receiver. The peak detection unit has a register that stores a power value of only a measurement point in the vicinity of the peak including a rising and falling part of the peak
The radio receiver according to claim 2, wherein the detection result storage unit has a configuration in which a power value stored in a register at a center position of the register of the peak detection unit is input as the power value of the peak. The peak detection unit turns on a determination enable signal that activates a peak determination function when a power value is stored in a register at a central position among registers that store only power values of measurement points near the peak. Set,
When a power value lower than the power value stored in the center position register is input in a state where the determination enable signal is set to ON, the power value stored in the center position register is changed to the peak power. The radio receiver according to claim 3, wherein the radio receiver is configured to determine a value and represent a peak arrival timing and to output a clear signal for erasing data stored in a register of the peak detection unit.

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