JP2001267958A - Delay profile generator and delay profile generation method - Google Patents

Abstract

(57) [Problem] To enable appropriate synchronization detection even if deterioration of a communication channel environment such as a reception level largely fluctuating due to fading or the like occurs. A delay profile obtained by despreading is observed a plurality of times between correlations for each cycle of a spreading code, and if the variance at that time is smaller than a predetermined value, the averaging time becomes longer. Determine the number of delay profile averaging as described above, if the variance is larger than a predetermined value, determine the number of delay profile averaging so that the averaging time is shorter,
The averaging circuit 12 that controls the averaging of the delay profile is controlled by using the determined number of averaging of the delay profile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CDMA (Code D)
The present invention relates to a delay profile generator and a delay profile generation method suitable for use in a mobile station apparatus and a base station apparatus of an ivision Multiple Access (communication) method.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a configuration of a delay profile generator used in a conventional CDMA communication type radio apparatus. As shown in this figure, decimation circuits 1 and 2, matched filters 3 and 4, code generators 5 and 6, adder 7, subtractor 8, SQRT (square-sum root calculator) 9, It comprises a RAM 10 and an averaging circuit 11.

In this conventional delay profile generator, a demodulated I (in-phase component) Q (quadrature component) signal is decimated by decimation circuits 1 and 2 and an I signal is input to a matched filter 3 to generate a Q signal. Is matched filter 4
Is input to The matched filter 3 calculates the correlation value with the code generated by the code generator (for I) 5, and the matched filter 4 calculates the correlation value with the code generated by the code generator (for Q) 6 Is done.

[0004] After the correlation value is obtained, complex despreading is performed in the adder 7 and the subtractor 8. That is, the adder 7 adds the I component and the Q component to eliminate the Q component, and the subtractor 8 subtracts the I component and the Q component to eliminate the I component. After complex despreading is performed,
In the SQRT 9, the root of the sum of squares of the I component and the Q component is calculated, and the result is stored in the RAM 10. Note that a delay profile of a specific section is stored in the RAM 10. The averaging circuit 11 performs averaging from the delay profile of a specific section stored in the RAM 10 and outputs the result.

[0005]

However, in the conventional delay profile generator, since the time for averaging the delay profile is constant, fading occurs depending on the reception environment and the fluctuation of the reception level becomes large. In such a case, there is a problem that an appropriate synchronization detection cannot be performed, and an error occurs in communication.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a delay profile generation method capable of performing appropriate synchronization detection even when a communication path environment is deteriorated such as a reception level largely fluctuating due to fading or the like. And a method for generating a delay profile.

[0007]

A delay profile generator according to the present invention stores a delay profile generated by the delay profile generator, the delay profile generator generating a delay profile from a despread received signal. Storage means, an averaging means for averaging and outputting the delay profiles stored in the storage means, and a delay profile analysis means for analyzing the number of delay profile averaging based on the delay profiles stored in the storage means And an averaging control unit that adaptively changes an averaging method in the averaging unit based on the analysis result of the delay profile analysis unit.

Further, the delay profile generator according to the present invention comprises: a delay profile generator for generating a delay profile from a despread received signal; and a storage unit for storing the delay profile generated by the delay profile generator. Averaging means for averaging and outputting the delay profiles stored in the storage means, and fetching a delay profile generated by the delay profile generating means, and analyzing the number of times of delay profile averaging based on the fetched delay profile. And a averaging control unit that adaptively changes an averaging method in the averaging unit based on an analysis result of the delay profile analyzing unit.

Further, in the delay profile generator according to the present invention, in the delay profile generator, the delay profile analysis means observes the correlation value for each spreading code cycle a plurality of times, and sets the resulting dispersion value to a predetermined value. And the delay profile averaging number is determined based on the result, and the averaging control means uses the delay profile averaging number determined by the delay profile analysis means to calculate the delay profile average in the averaging means. A configuration to control the activation time is adopted.

Further, in the delay profile generator according to the present invention, in the delay profile generator, the delay profile analysis means may include a delay profile averaging count such that the averaging time becomes longer when the variance is smaller than a predetermined value. Is determined, and when the variance value is larger than the predetermined value, the number of delay profile averaging times is determined such that the averaging time is shortened.

[0011] According to these configurations, even if the communication path environment deteriorates, such as the reception level fluctuating greatly due to fading or the like, a delay profile is created in accordance with the fluctuation. And communication errors and the like are reduced.

A path detecting apparatus according to the present invention employs a configuration including the delay profile generator.

A synchronization holding apparatus according to the present invention employs a configuration including the delay profile generator.

A mobile station apparatus according to the present invention employs a configuration including the above-described delay profile generator.

A base station apparatus according to the present invention employs a configuration including the above-described delay profile generator.

According to each of the above-described devices, the synchronization detection capability is improved, and highly reliable communication with few errors can be performed.

According to the delay profile generation method of the present invention, a delay profile obtained by despreading is observed a plurality of times between correlations of each spreading code cycle, and when the variance at that time is smaller than a predetermined value, Determines the number of delay profile averaging so that the averaging time becomes longer, and when the variance is larger than the predetermined value, determines the number of delay profile averaging so that the averaging time becomes shorter. The delay profile averaging time is controlled using the obtained delay profile averaging number.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The gist of the present invention is to analyze the number of delay profile averaging times from a delay profile obtained by despreading, and to adaptively change the delay profile averaging method based on the analysis result. It is to be.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a delay profile generator according to an embodiment of the present invention. In this figure, parts common to those in FIG. 3 described above are denoted by the same reference numerals, and description thereof is omitted.

In this figure, the delay profile generator of the present embodiment has the configuration of the delay profile shown in FIG.
Delay profile analyzer 13 and averaging circuit control circuit 1
4 is added. The averaging circuit 12
The delay profile averaging time can be varied from outside (in the present embodiment, the averaging circuit control circuit 14).

The delay profile analyzer 13 observes the correlation value for each spreading code cycle a plurality of times, compares the resulting variance with a predetermined value, and determines the number of delay profile averaging based on the result. I do. For example, if the variance is smaller than a predetermined value, the number of delay profile averaging is determined so that the averaging time becomes longer. If the variance is larger than a predetermined value, the delay profile averaging is performed so that the averaging time becomes shorter. Determine the number of conversions. The averaging circuit control circuit 14
The delay profile averaging time in the averaging circuit 12 is controlled based on the delay profile averaging count determined by the delay profile analyzer 13.

In the delay profile generator having such a configuration, the IQ signals demodulated from the received signal are decimated by the decimation circuits 1 and 2 and input to the matched filters 3 and 4, respectively. Then, the matched filters 3 and 4 determine the correlation values with the spread codes generated by the code generator (I) 5 and the code generator (Q) 6. After complex despreading is performed in the adder 7 and the subtractor 8, the SQRT
The root of the sum of squares is calculated at 9 and the result is stored in the RAM 10. The delay profile analyzer 13 observes the correlation value for each code cycle n (n = 1, 2, 3,...) Times for the delay profile stored in the RAM 10 (specific section).

If the observed variance is smaller than the predetermined value, the number of delay profile averaging times is determined in a direction to increase the delay profile averaging time. On the other hand, when the observed dispersion value is larger than the predetermined value, the number of delay profile averaging times is determined in a direction to shorten the delay profile averaging time. The averaging circuit control circuit 14 determines the averaging circuit 1 based on the number of times of delay profile averaging determined by the delay profile analyzer 13.
2 controls the delay profile averaging time.

As described above, in the present embodiment, the RAM 1
A plurality of observations are made between the correlations for each cycle of the spreading code with respect to the delay profile stored in 0, and if the variance at that time is smaller than a predetermined value, the delay profile averaging is performed in a direction in which the averaging time becomes longer. The number of times is determined, and when the variance is larger than a predetermined value, the number of delay profile averaging times is determined in a direction to shorten the averaging time. Then, the delay profile averaging time in the averaging circuit 12 is controlled based on the determined delay profile averaging number.

Therefore, even if the communication channel environment is deteriorated such as the reception level fluctuates greatly due to fading or the like, a delay profile is created in accordance with the fluctuation, so that the synchronization detection capability is improved and errors are reduced. Reliable communication becomes possible.

(Embodiment 2) FIG. 2 is a block diagram showing a configuration of a delay profile generator according to an embodiment of the present invention. In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

In the delay profile generator of the first embodiment, the delay profile analyzer 13 reads out and analyzes the delay profile stored in the RAM 10. However, in the delay profile generator of the present embodiment, The difference is that the delay profile analyzer 15 directly takes in and analyzes the delay profile from the SQRT 9. The operation of controlling the delay profile averaging time by analyzing the delay profile is exactly the same, and a description thereof will be omitted.

In the first and second embodiments, before calculating the root of the sum of squares by SQRT2, the IQ signal after demodulation is integrated for several symbols and then the root of the sum of squares is calculated. You may do it.

Further, the first and second embodiments are naturally used for a base station apparatus and a mobile station apparatus of the CDMA communication system, so that the synchronization detection capability of these apparatuses is improved, and high reliability with few errors is obtained. Communication can be enabled. A specific application point in these devices is a path detection device or a synchronization holding device.

[0031]

As described above, according to the present invention,
It is possible to create a delay profile according to the reception environment, and as a result, the synchronization detection capability is improved, and communication errors and the like can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a delay profile generator according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of a delay profile generator according to Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional delay profile generator.

[Explanation of symbols]

 1, 2 decimation circuit 3, 4 matched filter 5, 6 code generator 7 adder 8 subtractor 9 SQRT 10 RAM 12 averaging circuit 13, 15 delay profile analyzer 14 averaging circuit control circuit

Claims (9)

[Claims] 1. A delay profile generating means for generating a delay profile from a despread received signal, a storage means for storing a delay profile generated by the delay profile generating means, and a delay stored in the storage means. Averaging means for averaging and outputting the profile, delay profile analyzing means for analyzing the number of delay profile averaging based on the delay profile stored in the storage means, and Averaging control means for adaptively changing an averaging method in the averaging means. 2. A delay profile generating means for generating a delay profile from a despread received signal, a storage means for storing the delay profile generated by the delay profile generating means, and a delay stored in the storage means. Averaging means for averaging and outputting the profile, a delay profile analyzing means for capturing a delay profile generated by the delay profile generating means, and analyzing a delay profile averaging count based on the captured delay profile, Averaging control means for adaptively changing an averaging method in the averaging means based on an analysis result of the delay profile analysis means. 3. The delay profile analysis means observes a correlation value for each spreading code cycle a plurality of times, compares the resulting variance with a predetermined value, and calculates a delay profile averaging count based on the result. The averaging control means determines and averages the delay profile averaging time in the averaging means using the number of times of delay profile averaging determined by the delay profile analyzing means. 3. The delay profile generator according to 2. 4. The delay profile analysis means determines a delay profile averaging count so that the averaging time becomes longer when the variance value is smaller than a predetermined value, and when the variance value is larger than the predetermined value, the average is calculated. 4. The delay profile generator according to claim 3, wherein the delay profile averaging time is determined so as to shorten the delay time. 5. A path detection device comprising the delay profile generator according to claim 1. Description: 6. A synchronization holding device comprising the delay profile generator according to claim 1. Description: 7. A mobile station apparatus comprising the delay profile generator according to any one of claims 1 to 4. 8. A base station apparatus comprising the delay profile generator according to any one of claims 1 to 4. 9. A delay profile obtained by despreading is observed a plurality of times between correlations for each period of a spreading code, and when the variance at that time is smaller than a predetermined value, the averaging time is longer. Determine the number of delay profile averaging so that, if the variance is greater than the predetermined value, determine the number of delay profile averaging so that the averaging time is short, and determine the determined number of delay profile averaging A delay profile averaging time is controlled using the delay profile averaging time.