JP2002232326A - Path detection method, path detector and array antenna receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a path detector with which the improving effect of path detection characteristics is high and even an initial directional beam used for antenna synthesis is detected in an array antenna receiver. SOLUTION: A sliding correlation device 102 inversely spreads the signals of a plurality of chips for respective antennas, a multi-beam former 103 generates signal sequences for respective directional beams from the inversely spread signal sequence, and a part 104 averages the signal sequences and generates delay profiles for the respective directional beams. A delay profile selection/synthesis part 105 synthesizes the delay profiles and generates a synthetic delay profile, a path timing detector 106 detects a multi-path timing from the synthetic delay profile, and an initial weight generator 107 generates the initial value of the antenna weight of the respective directional beams for path reception from level information indicating the level values of the respective delay profiles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a path detecting apparatus for an array antenna system, and more particularly, to a code division multiple access (CDMA) signal received by an array antenna system to detect the timing of multipath and to detect the timing of each path. The present invention relates to a path detection device that forms an initial antenna beam.

[0002]

2. Description of the Related Art In a code division multiple access (CDMA) system, it is said that a subscriber capacity for a frequency band is increased as compared with a conventional system, and is expected as a radio access system of a next-generation mobile communication system.

In a CDMA mobile communication system, a plurality of user signals coexist on the same frequency, so that in a base station receiving apparatus, other user signals become interference waves with respect to a desired user signal. As means for reducing the influence of this interference, there is an adaptive array antenna. The adaptive array antenna
A signal is received by a plurality of antennas, and a complex number is weighted to the signal received by each antenna (hereinafter, referred to as antenna weight).
(Hereinafter, referred to as antenna combining). By controlling the amplitude and phase of the received signal at each antenna, a directional beam suitable for a desired user signal is formed, and interference due to other user signals is suppressed.

In a CDMA mobile communication system, a receiving device of a base station detects signals of a plurality of paths having different arrival timings (hereinafter, referred to as path timings) generated by a multipath propagation path, and detects each signal. The user signal is demodulated by rake combining. Also in the rake combining, each path is weighted (hereinafter, referred to as rake weight).

[0005] A path detecting device in the receiving device of the base station detects the path timing of each path and notifies the receiving demodulation unit of each path timing. The reception demodulation unit despreads the signals received by the plurality of antennas at each path timing notified from the path detection device. The reception demodulation unit combines the reception signals from the respective antennas with the directional beams. Further, the reception demodulation unit rakes the signals of each path to obtain a demodulation result of the user signal.

In a receiving system having a plurality of antennas, such as an adaptive array antenna, the SINR (signal-to-interference power ratio) per antenna decreases in proportion to the number of antennas. Therefore, when path detection is performed using only one antenna, the accuracy of path detection decreases.

Therefore, conventionally, a path detection device using reception signals of a plurality of antennas has been proposed. For example,
In a conventional path detection device using a plurality of antennas, there is a device that generates a delay profile for each antenna and combines them to smooth the delay profile and improve characteristics.

FIG. 8 shows an example of the configuration of a conventional receiving apparatus.

[0009] The conventional receiving device has a path detecting device 801 and a receiving demodulating unit 806.

[0010] The path detecting device 801 receives a CDMA signal by an array antenna (not shown) and detects a path. Here, the array antenna is assumed to be composed of M antennas.

The path detecting device 801 includes a sliding correlator 802, a delay profile generating unit 80 for each antenna,
3. It has a delay profile synthesizing unit 804 and a path timing detecting unit 805.

[0012] Sliding correlator 802 includes spread signals S811, S812, ..., S81 received by each antenna.
M is spread over a plurality of chips, and 1 / N _R (N
_(R is an integer of 1 or more), and despreads each at a resolution, and outputs them as a despread signal sequence.

A delay profile generator 803 for each antenna
Calculates a vector average in phase with respect to the despread signal sequence output from the sliding correlator 802 and calculates its amplitude level or power level. Further, the antenna-dependent delay profile generation unit 803 averages a vector average amplitude level or power level of the despread signal sequence for a predetermined time. Accordingly, the antenna-dependent delay profile generation unit 803 generates a delay profile corresponding to each antenna, averaged over a predetermined time.

The delay profile combining section 804 combines the delay profiles corresponding to the respective antennas to generate one delay profile (hereinafter, referred to as a combined delay profile).

The path timing detection section 805 selects L path timings used for rake combining in the reception demodulation section according to the combined delay profile. As a method of selecting a path timing in the path timing detection unit 805, there is a method of sequentially selecting paths having a large amplitude level or power level from a combined delay profile. However, 0.75
Generally, a path selection interval of チ ッ プ 1 chip is set. That is, a path that is 0.75 to 1 chip before and after the previously selected path is not selected.

The reception demodulation unit 806 includes L path reception units 8
, 807L, and a combiner 812, and demodulates the signal of each path at the path timing detected by the path detector 801 and performs rake combining to output a user signal.

The path receiving section 8071 includes a correlator 8081,
Beamformer 8091, Rake combining weighting section 810
1. It has a weight adaptive control unit 8111.

Similarly, the path receiving units 8072,.
07L are correlators 8082,.
809L, rake combining weighting sections 8102,..., 810L, and weight adaptive control sections 8112,. Path receiving unit 80
, 807L have the same configuration, and each of the spread signals S
., S81M are received.

The following description focuses on the path receiving section 8071.

The correlator 8081 despreads the spread signals S811, S812,..., S81M received by each antenna at the path timing detected by the path timing detector 805.

The beamformer 8091 includes a correlator 808
1 is received, the antennas are combined with a given weight (antenna weight) for forming a directional beam adapted to each user, and a path signal S821 is output.

Rake combining weighting section 8101 performs weighting (rake weighting) on path signal S821 to compensate for carrier phase fluctuation and maximize the combined SINR, and outputs weighted path signal S831.

The weight adaptive control unit 8111 adaptively updates the antenna weight using the output of the correlator and the determination error of the path signal S821. As a control operation of the weight adaptive control unit 8111, for example, least mean square error (MMSE) control or the like is used. For MMSE, refer to Japanese Patent Application No. 2000-
No. 256549 describes this in detail.

The synthesizer 812 includes a rake combining weighting unit 8
, 810L output by weights 1011, 8102,..., 810L, respectively, to generate high-quality rake-combined demodulated outputs.

[0025]

The conventional path detecting device 8
No. 01 smoothes the delay profile by combining the level (amplitude or power) of the delay profile of each antenna, and improves the path detection characteristics by ensuring the discrimination between the peak of the path and noise. However, the path detecting device 80
1 does not directly improve the SINR (difference between path peak and noise level) of each delay profile,
There is a limit in improving the path detection characteristics.

Although the conventional path detecting device 801 can detect the timing of each path, it cannot know the initial directional beam used for antenna synthesis by the beamformer 809 of the reception demodulation unit 806. The beam former 809 uses, for example, a predetermined initial directivity beam. If a preferred initial directional beam can be known, a better antenna combining effect than at the initial time can be obtained.

An object of the present invention is to provide a path detecting apparatus which has a high effect of improving path detection characteristics in an array antenna receiving apparatus and also detects an initial directional beam used for antenna synthesis.

[0028]

In order to achieve the above object, a path detecting method according to the present invention is a path detecting method for receiving a code division multiple access signal by an array antenna and detecting a multipath timing. Receiving the despread signal sequence of each antenna of the array antenna with a plurality of directional beams, generating a delay profile for each directional beam, and calculating the delay profile for each directional beam. Selecting at least one delay profile having a large level value for each timing, generating a combined delay profile by adding the level values, and detecting the timing of the multipath from the combined delay profile. .

According to the present invention, the despread signal sequence of each antenna is received by a plurality of directional beams, and each multi-path signal is obtained from a combined delay profile obtained by selectively adding a level value from a delay profile for each directional beam. Detect timing.

According to an embodiment of the present invention, the timing of the multipath is detected from the combined delay profile, and each level of each directional beam is obtained from level information indicating a level value for each timing in the delay profile. An initial value of a directional beam for path reception for receiving a path is generated.

Therefore, when detecting the timing of each path of the multipath, the level information indicating the level value of each delay profile at each timing detected is utilized,
An initial weight of the directional beam for each path reception can be generated.

A path detecting apparatus according to the present invention is a path detecting apparatus which receives a code division multiple access signal by an array antenna and detects the timing of multipath, and includes a plurality of chips for each antenna of the array antenna. A sliding correlator for despreading a signal and outputting a despread signal sequence, and a multi-beamformer for receiving the signal sequence output for each antenna with a plurality of directional beams and outputting a signal sequence for each directional beam Taking an average of the signal sequence for each directional beam at a predetermined time, and a beam-by-beam delay profile generating means for generating a delay profile for each of the directional beams; and At least one delay profile having a large level value is selected for each timing, and the level values are added to generate a composite delay profile. A delay profile selection / combining means for generating a file, a path timing detecting means for detecting the timing of said multipath from said combined delay profile.

According to an embodiment of the present invention, an antenna for forming a path receiving directional beam for receiving each path from level information indicating a level value for each timing in the delay profile of each directional beam. The apparatus further includes initial weight generation means for generating an initial value of the weight.

A receiving apparatus according to the present invention is a receiving apparatus that receives a code division multiple access signal by an array antenna and rake-combines a multipath signal, wherein the signal is transmitted over a plurality of chips for each antenna of the array antenna. Despread,
A sliding correlator that outputs a despread signal sequence, a multi-beamformer that receives the signal sequence output for each antenna with a plurality of directional beams, and outputs a signal sequence for each directional beam, and the directional beam An average of the signal sequence for each beam at a predetermined time, a beam-by-beam delay profile generating means for generating a delay profile for each of the directional beams, and a level value for each timing from the delay profile for each of the directional beams. Delay profile selection / selecting at least one large delay profile and adding the level values to generate a combined delay profile
Combining means, path timing detecting means for detecting the timing of the multipath from the combined delay profile, and receiving each path from level information indicating a level value for each timing in the delay profile of each directional beam. Weight generating means for generating an initial value of an antenna weight for forming a directional beam for path reception, and corresponding to the timing of the multipath, despreading each spread signal received by the array antenna at the timing. At least one correlator and a correlator are provided corresponding to the correlator, form a directional beam for path reception with a given antenna weight, and output a signal output from the corresponding correlator for the path reception. A beamformer for receiving a directional beam and a beamformer provided corresponding to the beamformer, The antenna weights as the initial value,
Then, the antenna weight is adaptively updated using the signal despread by the correlator and the determination error of the beamformer, and a weight adaptive control means for giving to the beamformer is provided corresponding to the beamformer. To compensate for carrier phase fluctuations and SINR after rake combining.
Rake combining weighting means for weighting the output of the corresponding beamformer so that the maximum value is obtained, and a combiner for generating the demodulated output by adding the outputs of the rake combining weighting means.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means selects a delay profile having the largest level value for each timing from the delay profile for each of the directional beams, and sets the level value to the selected one. This is the level value of the combined delay profile.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means has a delay profile having the largest level value for each timing and a delay profile having the second largest level value, for each of the directional beams. A delay profile is selected, and the level values are added to generate a composite delay profile.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means, for each timing of the delay profile for each of the directional beams, includes a delay profile having the largest level value and a delay profile having the second largest level value. When the delay profiles are those of the directional beams adjacent to each other, the second largest level value is added to the largest level value to generate the combined delay profile.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means includes, for each of the timings of the delay profile for each of the directional beams, the delay profile of a natural number N delay profiles from the one having the largest level value. The combined delay profile is generated by sequentially adding level values.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means, for each timing of the delay profile for each of the directional beams, includes a predetermined range from the level value of the delay profile having the largest level value. Among them, the level values of N natural number delay profiles are sequentially added from the one with the largest level value to generate the combined delay profile.

According to an embodiment of the present invention, the delay profile selecting / synthesizing means sets, at each timing of the delay profile for each of the directional beams, a level value of the average noise of the delay profile for each of the directional beams. The synthetic delay profile is generated by sequentially adding the level values of the N natural number of delay profiles in order from the one having the level value larger than the level and having the largest level value.

According to an embodiment of the present invention, the initial weight generating means sets the weight of the directional beam having the largest level value from the level information as the initial weight.

According to the embodiment of the present invention, the initial weight generating means may determine the level value of the directional beam having the largest level value from the level information and the next directional beam adjacent to the directional beam. A weight for forming the directional beam having the largest level value, or an intermediate directional beam between the directional beam and the adjacent directional beam, according to a ratio of the directional beam having the largest level value to the level value. A weight for forming a sex beam is set as an initial weight.

[0043]

Embodiment of the embodiment of the present invention will be described with reference to the drawings in detail.

Referring to FIG. 1, the array antenna receiving apparatus according to one embodiment of the present invention has a path detecting apparatus 101 and a receiving demodulation unit 108. Here, it is assumed that the array antenna (not shown) includes N antennas.

The path detecting device 101 calculates a code division multiple access (CDMA) signal received by the array antenna
In order to detect a path suitable for rake combining, a sliding correlator 102, a multi-beamformer 103, a delay profile generating unit 104 for each beam, a delay profile selecting / combining unit 105, a path timing detecting unit 106, and an initial weight generating unit 107 are used. Have.

The reception demodulation unit 108 has L path reception units 1
, 109L, and a combiner 114. The reception demodulation unit 108 demodulates the signal of each path at the path timing detected by the path detection device 101, performs rake combining, and generates a demodulated output. In this rake combining, signals of a maximum of L paths are combined. Path receiving unit 1091
Has a correlator 1101, a beamformer 1111, a rake combining weighting unit 1121, and a weight adaptive control unit 1131. Similarly, path receiving units 1092,...
Are correlators 1102,.
, L, beamformers 1112,..., 111L, rake combining weighting sections 1122,. Path receiving unit 109
, 109L have the same configuration,
At each corresponding path timing, the spread signal S11
, S112,..., S11N are received.

The sliding correlator 102 receives the spread signals S111, S112,.
N is spread over a plurality of chips and despread at a resolution of 1 / N _R (N _R is an integer of 1 or more) of the chip period, and outputs them as despread signal sequences S121, S122,..., S12N.

The multi-beamformer 103 outputs the despread signal sequence S1 output from the sliding correlator 102.
, S12N are received by M directional beams (hereinafter, referred to as multi-directional beams), and signal sequences S131, S132,..., S13M for each directional beam are received.
Is output.

Referring to FIG. 2, the multi-beamformer 103 includes multipliers 2111, 112,.
, 212N,..., Multipliers 21M1, 21M2,.
, 22M.

Multipliers 2111, 122,..., 212N
Weights the signal sequences S121, S122,..., S12N, respectively. The synthesizer 211 includes a multiplier 2111,
, 212N are combined to form a signal sequence S1
31 is output.

Similarly, multiplier 2122 weights signal sequence S122. The synthesizer 222 includes the multiplier 21
, 212N are combined to generate a signal sequence S132. Further, similarly, the multiplier 21
, 21MN and a combiner 22M. Note that the multi-beamformer 103 can be formed into an IC, and in that case, the amount of software calculation is almost the same as that of the conventional one.

.., 211
, 212N, to the multipliers 21M1, 21M2,..., 21MN are predetermined values for forming the M directional beams of the multi-beamformer 103. .

FIG. 6 is a graph showing an example of a multi-directional beam of the multi-beamformer 103 when the number of directional beams is M = 6 and the number of antennas is N = 6. An array antenna in which six antennas are linearly arranged. 2 shows an orthogonal multi-beam pattern including six directional beams.

FIG. 7 is a graph showing an example of a multi-directional beam of the multi-beamformer 103 when the number of directional beams is M = 12 and the number of antennas is N = 6, and an array antenna in which six antennas are linearly arranged. 2 shows an orthogonal multi-beam pattern including 12 directional beams.

Beam-based delay profile generator 104
Calculates the average of the signal sequences S131, S132,..., S13M input from the multi-beamformer 103 in a fixed cycle, and obtains a delay profile S14 for each beam.
, S142,..., S14M are generated.

FIG. 3 is a block diagram showing the configuration of the beam-by-beam delay profile generator 104. As shown in FIG. The beam-by-beam delay profile generation unit 104 includes a beam-by-beam in-phase averaging unit 30.
1, a level detector 302 for each beam and a level averaging section 303 for each beam.

The beam-by-beam in-phase averaging section 301 receives the signal sequences S131 and S1 input from the multi-beamformer 103.
A vector average is calculated in phase for a predetermined number of symbols of 32,..., S13M. The beam level detection unit 302
The level (amplitude or power) of each output of the in-phase common-mode averaging unit 301 is calculated. Level averaging unit 303 for each beam
Calculates the average of each output of each beam level detection unit 302 for a predetermined time, and calculates the delay profiles S141 and S141.
, S14M are generated.

The beam-by-beam in-phase averaging unit 301 adds the phases of the despread symbols of the signal sequences S131, S132,.
R is greatly improved.

When a symbol is modulated, the modulation must be removed. In that case, if it is a pilot signal, modulation can be removed with a known pilot symbol, and addition in phase is possible.

Although the SINR is improved as the number of in-phase averaged symbols increases, the number of averaged symbols is limited when the phase changes rapidly due to fading or the like. The number of symbols to be averaged in the in-beam in-phase averaging unit 301 and the method of average weighting are arbitrary, and an optimum one may be selected according to the mode to which the present apparatus is applied.

The path detecting apparatus 101 of the present embodiment
The beam-by-beam in-phase averaging unit 301 may be placed before the multi-beamformer 103. This configuration may reduce the amount of calculation in some cases. In this case, the per-beam in-phase averaging unit 301 takes the in-phase average for each antenna instead of taking the in-phase average for each beam. This case is similar in principle, and is included in the present invention.

The delay profile selection / synthesis unit 105
M delay profiles S141, S142,..., S1
The level of 4M is measured at each timing, and one or more delay profiles having a large level at each timing are selected from the delay profiles S141, S142,..., S14M, and their level values are added. One delay profile (hereinafter, referred to as a combined delay profile) is generated and output to the path timing detection unit 106. The delay profile selection / synthesis unit 105 notifies the initial weight generation unit 107 of the result of measuring the level of each delay profile S141, S142,..., S14M at each timing as level information.

The delay profile selection / synthesis unit 105
It is a constituent element of the present invention, and several means can be considered for its selection and synthesis method. And
Suitable means will depend on the shape of the multi-beam pattern.

For example, when multi-directional beams are densely arranged as shown in FIG. 7, even when a signal arrives from an intermediate direction between two directional beams, only one directional beam is selected. There is almost no level deterioration. Therefore, the delay profile selecting / synthesizing unit 105 may select one large-level delay profile from the M delay profiles for each timing, and use that level as the level of the synthesized delay profile.

On the other hand, if each directional beam of the multi-directional beams is sparsely arranged, if the signal arrives from an intermediate direction between the two directional beams, one directional beam The level degradation is large only by selecting.

In the example shown in FIG. 6, if only one directional beam is selected, when a signal arrives from the center of two directional beams, the level described in the combined delay profile is different from the original level. This is a value degraded by about 4 dB.

Therefore, for example, the delay profile selection /
The synthesizing unit 105 selects two high-level delay profiles from the M delay profiles for each timing and adds the level values to generate a synthesized delay profile.

However, if two delay profiles are always selected for each timing, noise is added when a signal arrives from the peak direction of a certain directional beam or when there is no path. Become. Therefore, the delay profile selection / synthesis unit 105 may set a constraint condition when adding the second level value.

As a first method of setting a constraint, when a signal arrives from an intermediate direction between two directional beams, the level value becomes higher in an adjacent directional beam. Therefore, when the directional beam of the second level value is adjacent to the first directional beam, a method of adding the second level value is considered.

As a second method, there is a method of adding the second level value when the difference between the first and second level values is equal to or smaller than a predetermined value.

As a third method, the first level value is M
When the average noise level of each of the delay profiles is larger than a certain level by a certain level, a method of adding a second level value that is within a certain level from the first level value is considered.

When the number of beam selections is extended to three or more, the same method as the second one can be applied. However, in the second and third methods described above, the number of directional beams to be combined is reduced. Too much noise is not desirable because noise increases.

The path timing detecting section 106 sequentially selects paths having a higher level than the combined delay profile.
However, a path selection interval of 0.75 to 1 chip is generally set. That is, a path that is 0.75 to 1 chip before and after the previously selected path is not selected.

The initial weight generation section 107 receives the path timing detected by the path timing detection section 106 and, based on the level information measured by the delay profile selection / combination section 105, the path reception section 1091 of each path of the reception demodulation section 108. ,
In 1092,..., 109L, weights used in the initial state (hereinafter, referred to as initial weights) are generated.

Several methods are conceivable for the initial weight generation method of the initial weight generation unit 107.

For example, a method is conceivable in which the weight used by the multi-beamformer 103 to form the directional beam having the highest level among the directional beams is used as the initial weight as it is.

As another method, a method of judging from a level value ratio between a directional beam having the highest level and a directional beam adjacent thereto and using a weight for forming an intermediate directional beam is used. Can be considered.

FIG. 5 is a flowchart showing a specific process of the present method. In FIG. 5, the beam number of the directional beam having the highest level is B ₁ and its level value is P ₁ .
The beam number of the directional beam having a higher level among the directional beams adjacent to B ₁ is B ₂ , and its level value is P ₂ . X is a predetermined threshold.

First, the initial weight generation unit 107 determines the level numbers B ₁ and B ₂ and the level values P ₁ and P ₂ (step 51). Next, the initial weight generation unit 107 determines that P ₁ / P ₂ ≧ X
It is determined whether or not [dB] (step 52).

The initial weight generation unit 107 determines that P ₁ / P ₂ ≧ X
If [dB], to select the weight of the directional beam of the beam number B ₁ (step 53). Further, if P ₁ / P ₂ <X [dB], the initial weight generation unit 107 places a directional beam (hereinafter, “intermediate”) between the directional beam of the beam number B _{1 and} the directional beam of the beam number B _2. A predetermined weight (intermediate weight) for forming a beam is referred to as an initial weight. According to this method, it is possible to easily generate a directional beam having higher accuracy than the resolution of the multi-beamformer 103, that is, an initial weight for forming an intermediate beam. In the case of the orthogonal multi-beam pattern of FIG. 6, the threshold value X is about 9 dB.

The path receiving units 1091, 1092,..., 10
Since 9L has the same configuration, the following description focuses on only the path receiving unit 1101.

Correlator 1101 despreads spread signals S111, S112,..., S11N at the path timing corresponding to itself, detected by path timing detection section 106.

At the time of initial operation, weight adaptive control section 1131
The initial weight given by the initial weight generation unit 107 is used as it is, and thereafter, the antenna weight is adaptively controlled in order to form a directional beam for receiving a path included in a multipath from each user. The weight adaptation control unit 1131 adaptively updates the antenna weight using the output of the correlator 1101 and the determination error of the path signal S151, and updates the beamformer 1
Notify 111. As a control operation of the weight adaptation control unit 1131, for example, least mean square error (MMSE) control or the like is used. For MMSE, refer to Japanese Patent Application No. 2000-
No. 256549 describes this in detail.

The beamformer 1111 includes the correlator 110
1 is received, the antenna is combined with the antenna weight notified from the weight adaptation control unit 1131, and the path signal S
151 is output.

FIG. 4 is a block diagram showing the configuration of the beamformer 1111.

The beamformer 1111 includes complex conjugate operation units 4111, 4112,..., 411N, multipliers 4211,
, 421N and a synthesizer 431.

The complex conjugate operation units 4111, 4112,...
411N performs a complex conjugate operation on the antenna weights input from weight adaptive control section 1131.

The multipliers 4211, 4212,..., 421N
Are each output of the correlator 1101 and the complex conjugate operation unit 411
, 411N are multiplied by the complex conjugate of the antenna weights.

The combiner 431 includes multipliers 4211 and 421
, 421N are added, and a pass signal S151 is added.
Output as

Rake combining weighting section 1121 compensates for carrier phase variation in path signal S151, performs weighting for rake combining so that the combined SINR becomes maximum, and outputs the result as signal sequence S161.

The synthesizer 12 has a rake combining weighting unit 11
, S16L output from 21, 1122,..., 112L are added to generate a high-quality demodulated output.

Next, the operation of this embodiment will be described.

First, path detecting apparatus 101 receives the CDMA signal received by the array antenna, and despreads the CDMA signal of each antenna by sliding correlator 102. Next, the path detecting apparatus 101 uses the multi-beamformer 103 to generate a signal sequence S131, S132,...
Generate Next, in the path detection apparatus 101, the beam-by-beam delay profile generation unit 104 averages the signal sequences S131, S132,...
141, S142,..., S14M are generated. Next, the path detecting apparatus 101 selects the delay profile selecting / combining unit 1
05, the delay profiles S141, S142,.
The level of 14M is measured at each timing, and one or more levels having a large level are selected at each timing, and the level values are added to generate a combined delay profile. Next, the path detection apparatus 101 selects a maximum of L paths whose level is larger than the combined delay profile in the path timing detection section 106 and inputs the path timing to the reception demodulation section 108. Further, the path detecting device 10
Reference numeral 1 denotes a detected path timing, an initial weight is generated by the initial weight generation unit 107 from the level information obtained by measuring the level of each delay profile S141, S142,..., S14M at each timing, and is input to the reception demodulation unit 108. I do.

The reception demodulation section 108 despreads the spread signals S111, S112,..., S11N at each path timing, adaptively controls the antenna weights of the beamformer using the initial weights as initial values, and adjusts the directivity for path reception. A multiplexed beam is formed, and the received signal sequence of each path is rake-combined.

According to the present embodiment, SINR is directly improved by receiving a directional beam for each despread signal sequence, and path detection is performed based on a combined delay profile generated from a delay profile for each directional beam. Thereby, excellent path timing detection characteristics can be realized.

Further, according to the present embodiment, the initial weight of the beamformer of each path can be generated from the level information of each directional beam at each path timing obtained for detecting the path timing. It is possible to combine antennas with a directional beam that is more preferable than the above stage.

Further, according to the present embodiment, the amount of software calculation can be suppressed to the same level as in the conventional case by integrating the multi-beamformer 103 into an IC.

[0098]

According to the present invention, the despread signal sequence of each antenna is received by a plurality of directional beams, and a multipath is obtained from a combined delay profile obtained by selectively adding a level value from a delay profile for each directional beam. , The SINR is improved, and excellent path timing detection characteristics can be realized.

Therefore, when detecting the timing of each path of the multipath, the level information indicating the level value of each delay profile at each timing detected is used to detect the timing.
Since the initial weight of the directional beam for each path reception can be generated, a better antenna combining effect than at the initial time can be obtained.

Further, by forming the multi-beamformer into an IC, the amount of software operation can be suppressed to the same level as in the conventional case.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an array antenna receiving device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of the multi-beamformer of FIG.

FIG. 3 is a block diagram showing a configuration of a beam-by-beam delay profile generator of FIG. 1;

FIG. 4 is a block diagram illustrating a configuration of a beam former of FIG. 1;

FIG. 5 is a flowchart illustrating an example of an initial weight generation method of an initial weight generation unit in FIG. 1;

FIG. 6 is a graph showing an example of a multi-directional beam of the multi-beamformer when the number of directional beams is M = 6 and the number of antennas is N = 6.

FIG. 7 is a graph showing an example of a multi-directional beam of the multi-beamformer 103 when the number of directional beams is M = 12 and the number of antennas is N = 6.

FIG. 8 is a block diagram illustrating a configuration example of a conventional receiving device.

[Description of Code] 101 Path detection device 102 Sliding correlator 103 Multi-beamformer 104 Beam-by-beam delay profile generation unit 105 Delay profile selection / combination unit 106 Path timing detection unit 107 Initial weight generation unit 108 Reception / demodulation unit 1091, 1092,. , 109L path receiving units 1101, 1102,..., 110L correlators 1111, 1112,..., 111L beamformers 1121, 1122,. 211N, 2121 to 212N, ..., 21M
.., 221N Multipliers 221, 222,..., 22M Combiner 301 In-phase average section for each beam 302 Level detection section for each beam 303 Level average section for each beam 4111, 4112,. , S11N Spread signal S121, S122, ..., S12N Despread signal sequence S131, S132, ..., S13M Signal sequence S141, S142, ..., S14M Delay profile S151, S152, ..., S15L Path signals S161, S162, ..., S16L Signal sequence 51 to 54 steps

Claims (21)

[Claims] 1. A path detection method for receiving a code division multiplex access signal by an array antenna and detecting a timing of multipath, wherein a despread signal sequence of each antenna of the array antenna is divided into a plurality of directional beams. Receiving, and generating a delay profile for each directional beam; selecting at least one delay profile having a large level value for each timing from the delay profile for each directional beam; And generating a combined delay profile by adding the multi-path to the multipath, and detecting the timing of the multipath from the combined delay profile. 2. A path for detecting each timing of the multipath from the combined delay profile and receiving each path from level information indicating a level value for each timing in the delay profile of each directional beam. 2. The path detection method according to claim 1, wherein an initial value of the directional beam for reception is generated. 3. A path detecting apparatus for receiving a code division multiplex access signal by an array antenna and detecting a multipath timing, wherein the signal is despread across a plurality of chips for each antenna of the array antenna, A sliding correlator that outputs a despread signal sequence; a multi-beamformer that receives the signal sequence output for each antenna with a plurality of directional beams and outputs a signal sequence for each directional beam; An average at a predetermined time of the signal sequence for each beam, a beam-by-beam delay profile generating means for generating a delay profile for each directional beam, and a level value for each timing from the delay profile for each directional beam. Selecting at least one large delay profile and adding the level values to generate a composite delay profile Path detection device comprising a rolled profile selection / combining means, a path timing detecting means for detecting the timing of said multipath from said combined delay profile. 4. An initial value of an antenna weight forming a directional beam for receiving a path for receiving each path is generated from level information indicating a level value for each timing in the delay profile of each directional beam. 4. The path detection device according to claim 3, further comprising an initial weight generation unit. 5. The delay profile selecting / synthesizing means, based on the delay profile for each of the directional beams,
5. The path detection device according to claim 3, wherein a delay profile having the largest level value is selected for each timing, and the level value is used as a level value of the combined delay profile. 6. The delay profile selecting / synthesizing means, based on the delay profile for each of the directional beams,
5. The path detection device according to claim 3, wherein a delay profile having the largest level value and a delay profile having the second largest level value are selected for each timing, and the level values are added to generate a combined delay profile. 7. The delay profile selecting / synthesizing unit, wherein, for each timing of the delay profile for each of the directional beams, the delay profile having the largest level value and the delay profile having the second largest level value are adjacent to each other. Adding the second largest level value to the largest level value if it is a directional beam;
The path detection device according to claim 3, wherein the combined delay profile is generated. 8. The delay profile selecting / synthesizing unit sequentially adds the level values of N natural number delay profiles from the one with the largest level value at each timing of the delay profile for each of the directional beams. The path detection device according to claim 3, wherein the combined delay profile is generated. 9. The delay profile selecting / synthesizing means, for each timing of the delay profile for each of the directional beams, within the predetermined range from the level value of the delay profile having the largest level value, The path detection device according to claim 3, wherein the synthetic delay profile is generated by sequentially adding the level values of N natural number delay profiles in descending order. 10. The delay profile selecting / synthesizing means, wherein, at each timing of the delay profile for each directional beam, a level value is larger than an average noise level of the delay profile for each directional beam by a predetermined level or more. The path detection device according to claim 3, wherein the synthetic delay profile is generated by sequentially adding the level values of the N natural number delay profiles from the one with the largest level value. 11. The path detecting apparatus according to claim 4, wherein said initial weight generation means sets a weight of a directional beam having a largest level value from said level information as an initial weight. 12. The directional beam having the largest level value from the level information and the directional beam having the next largest level value among the directional beams adjacent to the directional beam. A weight for forming the directional beam having the largest level value, or a weight for forming a directional beam intermediate between the directional beam and the adjacent directional beam. The path detecting device according to claim 4, wherein the weight is set as an initial weight. 13. An array antenna receiving apparatus for receiving a code division multiple access signal by an array antenna and rake combining multipath signals, wherein the signal is despread across a plurality of chips for each antenna of the array antenna. A sliding correlator that outputs a despread signal sequence; a multi-beamformer that receives the signal sequence output for each antenna with a plurality of directional beams and outputs a signal sequence for each directional beam; An average of the signal sequence for each directional beam at a predetermined time, and a delay profile generating means for each beam for generating a delay profile for each directional beam; and a level for each timing based on the delay profile for each directional beam. At least one delay profile having a large value is selected, and the level value is added to obtain a composite delay profile. A delay profile selecting / synthesizing unit, a path timing detecting unit for detecting the timing of the multipath from the combined delay profile, and level information indicating a level value for each timing in the delay profile of each directional beam. An initial weight generating means for generating an initial value of an antenna weight for forming a directional beam for receiving a path for receiving each path; and each spread received by the array antenna corresponding to the timing of the multipath. At least one correlator for despreading a signal at the timing; and a correlator provided corresponding to the correlator, forming a directional beam for path reception with a given antenna weight, output from the corresponding correlator. A beamformer for receiving the received signal with the directional beam for path reception; Is provided in correspondence with the initial weight of the antenna weight at the time of the initial operation, thereafter, adaptively update the antenna weight using the signal despread by the correlator and the determination error of the beamformer, Weight adaptive control means to be provided to the beamformer, provided corresponding to the beamformer, and weighting the output of the corresponding beamformer so as to compensate for carrier phase variation and maximize SINR after rake combining. An array antenna receiving apparatus comprising: a rake combining weighting means for performing the multiplexing; and a combiner for adding the outputs of the rake combining weighting means to generate a demodulated output. 14. The delay profile selecting / synthesizing means, based on the delay profile for each of the directional beams,
14. The array antenna receiving apparatus according to claim 13, wherein a delay profile having the largest level value is selected for each timing, and the level value is used as a level value of the combined delay profile. 15. The delay profile selecting / synthesizing means, based on the delay profile for each of the directional beams,
14. The array antenna receiving apparatus according to claim 13, wherein a delay profile having the largest level value and a delay profile having the second largest level value are selected for each timing, and the level values are added to generate a combined delay profile. 16. The delay profile selecting / synthesizing means, wherein, for each timing of the delay profile for each of the directional beams, the delay profile having the largest level value and the delay profile having the second largest level value are adjacent to each other. Adding the second largest level value to the largest level value if it is a directional beam;
14. The array antenna receiving device according to claim 13, wherein the combined delay profile is generated. 17. The delay profile selecting / synthesizing unit sequentially adds the level values of N natural number delay profiles from the one having the largest level value at each timing of the delay profile for each of the directional beams. 14. The array antenna receiving device according to claim 13, wherein the combined delay profile is generated. 18. The delay profile selecting / synthesizing unit, for each timing of the delay profile for each of the directional beams, within a predetermined range from the level value of the delay profile having the largest level value, 14. The array antenna receiving apparatus according to claim 13, wherein said composite delay profile is generated by sequentially adding said level values of N natural number delay profiles in descending order. 19. The delay profile selecting / synthesizing means, wherein at each timing of the delay profile for each of the directional beams, a level value is larger than an average noise level of the delay profile for each of the directional beams by a predetermined level or more; 14. The array antenna receiving apparatus according to claim 13, wherein the combined delay profile is generated by sequentially adding the level values of N natural number delay profiles from the largest one. 20. The array antenna receiving apparatus according to claim 13, wherein said initial weight generating means sets a weight of a directional beam having a largest level value from said level information as an initial weight. 21. The initial weight generating means, comprising: the level value of a directional beam having the largest level value from the level information; A weight for forming the directional beam having the largest level value, or a weight for forming a directional beam intermediate between the directional beam and the adjacent directional beam. 14. The array antenna receiver according to claim 13, wherein the weight is an initial weight.