JP2002198879A - Antenna diversity receiving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To composite signals by taking into consideration the correlation of an interference component between antennas and to make a signal power-to- interference power ratio (SIR) maximum regarding an antenna diversity receiving apparatus, which performs a multipath composition in a mobile radio communication terminal device or the like using a spectral diffusion system. SOLUTION: The signals which are received by two antennas 1-1, 1-2 so as to be A/D-converted are back-diffused at each antenna by a back-diffusion part 1-4 for each path at the same back-diffusion timing decided by a searcher 1-3. A conversion-factor and weighting-factor generation part 1-5 calculates a conversion factor and a weighting factor on the basis of a channel estimation value by a back-diffused signal for channel estimation, in such a way that the correlation of the interference component between the antennas is eliminated. The conversion factor and the weighting factor are multiplied by the back- diffused signal so as to be converted or weighted and composited by a signal conversion and composition part 1-6, and a composited signal is output to a signal processing part 1-7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna diversity receiving apparatus, and more particularly to an antenna diversity receiving apparatus for performing multipath combining in a mobile radio communication terminal apparatus using a spread spectrum system.

[0002]

2. Description of the Related Art FIG. 11 shows a signal combining section of a conventional antenna diversity receiving apparatus. In the receiving apparatus, radio signals input to the two antennas 11-10 and 11-20 respectively correspond to radio units 11-11 and 11-11 for each antenna.
11-21 perform low noise amplification and quadrature demodulation, etc., and perform analog / digital (A / D) conversion.
-22 is converted into a digital signal by each path (path #
After despreading for each of 0 to path # N-1), the despread signal for each path is synthesized by the synthesizing unit 11-4 to output a demodulated signal. As described above, in the spread spectrum receiving apparatus, the accuracy of the demodulated signal is increased by performing an operation called Rake combining in which the multipath signal is separated for each path and despread, and then combined.

In the above-described spread spectrum receiving apparatus, when antenna diversity reception is performed using two antennas, analog / digital signals from both antennas are received.
Using a signal after digital (A / D) conversion (hereinafter, referred to as “A / D conversion signal”), a path is detected by the searcher 11-3, and a despread timing is determined based on the detection timing of the path.

[0004] Using the despreading timing as a reference timing for each path, the data despreading units 11-13 and 11-23 for each antenna despread the received data signal. Although the configuration example of FIG. 11 performs despreading on signals from both antennas at a common despreading timing, the despreading timing is determined for each antenna for signals from each antenna. There is also a configuration that performs despreading.

The A / D-converted signals from both antennas are despread by data despreading sections 11-13 and 11-23, as well as channel estimation despreading sections 11-1 for each antenna.
4, 11-24, respectively, to perform despreading on the pilot pattern signal, and output the despread signal to the respective weight coefficient calculators 11-15, 11-25.

[0006] Weight coefficient calculation units 11-15 and 11-25
Calculates the weighting coefficients described below, and receives the weighting coefficients calculated by the weighting coefficient calculation units 11-15 and 11-25, which are despread by the data despreading units 11-13 and 11-23. The data signal is multiplied and weighted, and the despread reception data signal for each antenna and path for which the weighting has been performed is combined by the combining unit 11-4 to output a demodulated signal.

[0007] In general, the weighting factor calculators 11-15 and 11-25 calculate the magnitude of the desired signal for each path or the product of the magnitude of the desired signal and the reciprocal of the interference power as the weighting factor. A method of weighting and combining the product of the magnitude of the desired signal and the reciprocal of the interference power as a weighting factor is called maximum ratio combining.If there is no correlation between the interference components between each path and each antenna, the maximum ratio combining is performed. The signal power to interference power ratio (SIR) of the resulting signal is maximized.

FIG. 12 shows an example of the configuration of a conventional weight coefficient calculating section. The weighting factor calculation unit calculates a despread signal (complex number) of the pilot pattern signal from the channel estimation despreading unit.
The pilot pattern canceling unit 12-1 converts the pilot pattern into a pattern of, for example, all “1” to cancel the pilot pattern, and the averaging unit 12-2 averages the constant number of symbols (channel Estimated average value) is calculated, and the square of the average value is calculated by the square operation unit 12-3.

Further, the square value of the despread signal (complex number) of each pilot pattern signal from the channel estimation despreading unit is obtained by a square operation unit 12-4, and the square value (power of each symbol) is obtained. The averaging unit 12-5 calculates the average of the fixed number of symbols (the power average of each symbol), and subtracts the square of the above-described channel estimation average value from the power average, thereby dispersing the signal (interference power). Ask for.

The variance (interference power) of the signal is averaged by a smoothing unit 12-6 using past information, and the averaged interference power is converted into an inverse by an inverse conversion unit 12-7. Is multiplied by the above-described channel estimation average value to calculate a weight coefficient (complex number). Then, the complex conjugate of the weight coefficient (complex number) is multiplied by the above-described despread received data signal to remove the influence of the channel propagation path.

As described above, the signal obtained by combining the despread signal by weighting the product of the magnitude of the desired signal and the reciprocal of the interference power is a signal power-to-interference power ratio when there is no correlation between the interference components. Although (SIR) is maximized, there is a case where a correlation is generated in the interference component, in which case the signal power to interference power ratio (SIR) is not maximized.

For example, as shown in FIG. 13A, two paths (an antenna 13) are respectively provided from a base station 13-3 to diversity antennas 13-1 and 13-2 of a mobile radio communication terminal device (mobile device). To -1, pass 11 and pass 12,
Consider a propagation environment in which a signal reaches the antenna 13-2 from the paths 21 and 22).

Here, the path 11 has a propagation path coefficient α₁,delay
Time τ₁, Path 12 has a propagation path coefficient α _Two, Delay time τ_Two,
Path 21 has a propagation path coefficient β₁, Delay time τ₁, Pass 22
Propagation coefficient β_Two, Delay time τ_TwoAnd antenna
In 13-1, the path 12 is different from the path 11 by τ_Two−
τ₁Delay, and similarly at antenna 13-2, path 2
2 is τ for path 21_Two−τ₁Delay.

FIG. 13B shows the timing relationship of despreading in such a propagation environment. (B-1) is a despread code sequence, (b-2) is a received signal on path 11, (b-
3) shows the timing of the reception signal of the path 12, (b-4) shows the timing of the reception signal of the path 21, and (b-5) shows the timing of the reception signal of the path 22.

When the reception signal of the antenna 13-1 by the path 11 and the path 12 is despread at the despread timing of the path 11, and the reception signal of the antenna 13-2 by the path 21 and the path 22 When the despreading is performed at the despreading timing, the signal v _{2 obtained} by despreading the reception signals of the paths 12 and 22 is expressed by the following (Equation 1)
Becomes

[0016]

(Equation 1) However, v _{T, k} is the transmitted signal, p _k represents the despreading code, the desired signal is restored to despread at the correct time.

The interference signal is the sum of the signal component obtained by multiplying the despread signal v ₂ by the above (Equation 1) by the coefficient of the propagation path and noise. Therefore, assuming that the noise of the path 12 is v _{N, 1} and the noise of the path 22 is v _{N, 2} , the interference signal v
The interference signals v _{I, 2} of _{I, 1} and antenna 13-2 are v _{I, 1} = α ₂ v ₂ + v _{N, 1} , v _{I, 2} = β ₂ v ₂ + v _{N, 2} , and the noise component v _{N ,} except for _1, v _{N, 2,} the channel factor beta ₂ of channel coefficient alpha ₂ and path 22 pass 12, the correlation of the interference signal between the two antennas is determined.

That is, when signals from both antennas are despread at the same despread timing, the interference component is
If there is no influence of the propagation path, the result is exactly the same, and the correlation of the interference component between both antennas is determined only by the influence of the propagation path. Therefore, when the fading change of the propagation path is fast, the correlation of the interference components between the two antennas decreases due to the change of the propagation path condition. However, when the fading change is slow, the same propagation path state continues for a long time. Therefore, the propagation path coefficients α ₂ and β
_Since there is no variation in ₂ , the correlation between the interference signals between the two antennas is large.

[0019]

In a mobile radio communication terminal device or the like of a mobile communication system using orthogonal codes of a spread spectrum system, when a downlink channel signal is diversity-received by two antennas, a multipath signal of both antennas is transmitted. When despreading and synthesizing at the same timing, there is a case where a correlation occurs between the interference signals between the two antennas as described above. The interference power ratio (SIR) may not be maximum.

When there is no correlation between the interference components of the combined signals, the interference components cannot be canceled by using the mutual interference components. However, when antenna diversity reception is performed and signals from two antennas are despread at the same despread timing, the interference components can be canceled using the correlation between the interference components.

According to the present invention, in a mobile radio communication terminal device or the like in the above-mentioned spread spectrum mobile communication system, a signal power to interference power ratio is obtained by combining signals in consideration of the correlation of interference components between diversity receiving antennas. An object of the present invention is to provide an antenna diversity receiving apparatus capable of maximizing SIR).

[0022]

An antenna diversity receiving apparatus according to the present invention comprises: (1) an antenna for receiving a spread spectrum signal by two receiving antennas, despreading a multipath signal at the same despreading timing, and combining the signals; In the diversity receiver, the channel estimation value of each path is obtained,
Means for calculating a transform coefficient that eliminates the correlation of the interference signal between the two antennas based on the channel estimation value; and means for multiplying the signal after despreading by the transform coefficient to convert the signal into an uncorrelated signal of the interference signal. Means for synthesizing a signal obtained by converting the interference signal into a signal having no correlation.

(2) means for obtaining a channel estimation value of each path and calculating a transform coefficient for eliminating the correlation of the interference signal between the two antennas based on the channel estimation value; Means for calculating noise power and interference power including interference from neighboring cells from the despread signal for use, and a weight that maximizes the combined signal-to-interference power ratio based on the conversion coefficient, noise power, and interference power. Means for calculating a coefficient, and means for multiplying the despread signal by the weighting coefficient to synthesize a weighted signal.

(3) The means for calculating the transform coefficient is for calculating a transform coefficient for eliminating the correlation of the interference signal between the two antennas based on the channel estimation value of the largest path.

[0025]

FIG. 1 shows the main components of an antenna diversity receiving apparatus according to the present invention used in a mobile radio communication terminal apparatus and the like. FIG. 1 shows the configuration of an antenna diversity receiver for despreading and combining multipath signals of two antennas at the same despread timing.

In the antenna diversity receiving apparatus, the radio signals input to the first and second antennas 1-1 and 1-2 are applied to radio receiving units 1-11, 1 and 1, respectively.
-21 performs low noise amplification and quadrature demodulation, etc., converts them into digital signals by analog / digital (A / D) converters 1-12 and 1-22, and converts the A / D converted signals of the received signals of both antennas. Then, a path is detected by the searcher 1-3, and the despread timing is determined based on the detection timing of the path.

Then, the despreading section 1-4 for each path despreads the received signal of each antenna using the above despread timing as a reference timing. The despreading unit 1-4 includes:
A signal obtained by despreading a channel estimation signal such as a pilot pattern signal is output to transform coefficient / weight coefficient generation section 1-5, and a signal obtained by despreading the data signal is converted to signal conversion / combination section 1
Output to -6.

The conversion coefficient / weight coefficient generation section 1-5 calculates a conversion coefficient / weight coefficient based on the channel estimation value so as to remove the correlation of the interference component, and converts the coefficient into a signal conversion / synthesis section 1. Send to -6. The signal conversion / synthesis unit 1-6 converts the conversion coefficient / weight coefficient generation unit 1- 1 so that interference correlation is removed.
5 is multiplied by the spread signal of the data signal to synthesize a signal of each antenna and each path, and outputs the synthesized signal to the signal processing unit 1-7.

The signal processing section 1-7 includes a signal converting / combining section 1
It performs processing for decoding the code of the synthesized signal output from -6, and sends the output signal to a display device or a speaker or the like. A signal from a keyboard, a microphone, or the like is transmitted from the antenna 1-2 via the antenna duplexer 1-9 after quadrature modulation and power amplification are performed in the transmission unit 1-8.

FIG. 2 shows a simple concrete example of removing interference in consideration of the correlation between interference components of antennas. (A) of FIG.
Is the first path 11 (the propagation path coefficient α
₁ ) shows a state in which a desired signal is received by ₁ ) and an interference component is received by the second path 12 (a propagation path coefficient α ₂ ).
Also, (b) of the figure shows that the desired signal is received by the second antenna # 2 via the first path 21 (channel coefficient β ₁ ), and the interference component is received by the second path 22 (channel coefficient β ₂ ). Shows a state where is received.

In such a case, the signal received by the antenna # 1 is left as shown in FIG. 3C, and the interference component of the signal received by the antenna # 2 is changed by the antenna shown in FIG. The signal is rotated so as to cancel the interference component of the # 1 received signal. The rotation is performed by multiplying the reception signal of antenna # 2 by a conversion coefficient and converting the reception signal of antenna # 2. Then, by synthesizing the signals shown in FIGS. 9C and 9D, the signal from which the interference component has been removed can be synthesized as shown in FIG.

When the interference component becomes zero as in the example of FIG. 2, the signal power to interference power ratio (SIR) becomes infinite.
Even in the case where a noise component is included, the interference component cancels each other based on the correlation between the interference components of the two antennas, and then the signal is combined with an appropriate weighting coefficient, so that the signal-to-interference power ratio of the combined signal can be reduced. Can be max.

FIG. 3 shows an embodiment of the present invention for performing signal conversion that makes the above-mentioned interference uncorrelated. In the figure, first and second antennas 1-1 and 1-2, radio units 1-11, 1
−21, A / D converters 1-12, 1-22, Searcher 1
-3 is the same as that shown in FIG.
The above-described despreading section 1-4 in FIG. 1 corresponds to the data despreading sections 1-13 and 1-23 and the channel estimation despreading sections 1-14 and 1-24 in FIG.

A / D converters 1-12 for each antenna,
The A / D conversion signals output from 1-22 are respectively
Each data despreading unit 1-13, 1-23 corresponding to the antenna
And input to each channel estimation despreading section 1-14, 1-24, and each data despreading section 1-13, 1-23,
The data signal of the A / D conversion signal of the corresponding antenna is inversely converted.

The channel estimation despreading units 1-14,
1-24 despreads a channel estimation signal such as a pilot pattern signal, estimates the channel coefficients of all paths detected by the path searcher 1-3, and calculates the channel coefficients (channel estimation values). It is input to the transform coefficient generator 1-50.

The transform coefficient generator 1-50 performs a calculation described later using the channel estimation value to obtain a transform coefficient for eliminating the correlation between the interference signals between the two antennas. The conversion coefficient is input to the data variable conversion unit 1-6A and the channel estimation variable conversion unit 1-6B, and is input to the data variable conversion unit 1-6A.
6A converts the despread data signal (variable) for each antenna using the conversion coefficient.

Similarly, using the above-mentioned transform coefficients, the channel estimation variable transform section 1-6B transforms the despread pilot pattern signal (variable) for each antenna. The converted despread pilot pattern signal for each antenna is calculated by a weighting factor calculator 1-5 corresponding to each antenna.
1, 1-52.

With respect to the generation of the conversion coefficient in the above-described conversion coefficient generation unit 1-50, first, the calculation of the conversion coefficient in consideration of all the paths will be described. FIG. 4 shows a calculation flow of the conversion coefficient in this case. Transform coefficient generator 1-5
To 0, a despread signal of the channel estimation signal corresponding to each antenna is input, and a channel estimation value of each path is obtained from the despread signal (step 4-1). Where α _i , β
_i is a channel estimation value of the i-th path of each of the antennas 1-1 and 1-2.

The transform coefficient generator 1-50 converts the channel estimation values α _i , β _i into transform coefficients b _{n, 1, n} for the despread signal v _{1, n} , v _{2, n} of the n-th path of each antenna _{. 1} , b
_{n, 1,2} , b _{n, 2,1} , b _{n, 2,2} are calculated by the following (Equation 2) (step 4-2).

[0040]

(Equation 2)

The conversion coefficient b calculated by the above (Equation 2)
_{n, 1,1} , b _{n, 1,2} , b _{n, 2,1} , b _{n, 2,2} are converted into despread signals v _{1, n} , v _{2, n} of the n-th path of each antenna, By multiplying by the following (Equation 3), the despread signal v
_{1, n} , v _{2, n} are the uncorrelated signals u _{1, n} , u _{2, n}
Is converted to

[0042]

(Equation 3) Here, “ ^* ” represents a complex conjugate.

Next, a description will be given of the calculation of the conversion coefficient when only the correlation of the interference of the largest path is considered. FIG. 5 shows a calculation flow of the conversion coefficient in this case. The despread signal for channel estimation of each channel is input to the transform coefficient generation unit 1-50, and a channel estimation value of each path is obtained from the despread signal (step 5-1).

Next, the transform coefficient generating section 1-50 searches for a path where the power of the channel estimation value (total power of both antennas) is the largest (step 5-2). Here, it is assumed that the path having the power of the largest channel estimation value is the k-th path. The conversion coefficients b _{n, 1,1} , b _{n, 1,2} , b _{n, 2,1} , b _{n, 2,2} considering only the correlation of the interference of the path are
It is generated by the following (Equation 4) (step 5-3).

[0045]

(Equation 4)

FIG. 6 shows a configuration of a variable conversion unit for performing variable conversion according to the above (Equation 3) using the conversion coefficient calculated by the above (Equation 2) or (Equation 4). The variable transforming unit converts the despread signal v ₁ of the received signal of the antenna # ₁ and the transform coefficient b _1,1
The multiplier 6-1 for multiplying the complex conjugate, a multiplier 6-2 and despread signal v ₂ of the received signal of the antenna # 2 is multiplied by the complex conjugate of the transform coefficients b _{1, 2,} the received signal of the antenna # 1 A multiplier 6-3 that multiplies the despread signal v _{1 by} the complex conjugate of the transform coefficient b _2,1 and a multiplier that multiplies the despread signal v ₂ of the received signal of the antenna # _{2 by} the complex conjugate of the transform coefficient b _2,2 6-4.

Further, an adder 6-5 for adding the outputs of the multiplier 6-1 and the multiplier 6-2, a multiplier 6-3 and a multiplier 6-3
And an adder 6-6 for adding the outputs of the four. Each of the adders 6-5 and 6-6 outputs a converted signal.

The output signal from the channel estimation variable conversion unit 1-6B that has been converted according to the above (Equation 3) is output to the weight coefficient calculation units 1-51 and 1-52 corresponding to each antenna shown in FIG.
The weight coefficient calculation units 1-51 and 1-52 use the input signal to calculate weight coefficients by the configuration shown in FIG. 12, for example.

The output signal corresponding to each antenna from the data variable conversion unit 1-6A, which has been converted by the above (Equation 3), is added to the weight coefficient calculation units 1-51, 1 corresponding to the antenna.
-52 multiplies by the weighting factor output from the -52, outputs the weighted signal to the combining unit 1-6C, and the combining unit 1-6C adds all the signals that have undergone the same processing for each path. The signals are combined and output as a demodulated signal.

As a method of calculating the weighting factor, in addition to the above-described method of determining for each path, channel estimation values of all paths are obtained, and noise power including interference from neighboring cells and interference power of the own cell are obtained. And the signal-to-interference power ratio after combining in consideration of the correlation between the two antennas can be determined to be the maximum.

FIG. 7 shows an embodiment of the present invention in which the above-mentioned weighting factors are calculated to make the interference uncorrelated. FIG. 8 shows a flowchart of the calculation of the weighting factors. As shown in FIG. 7, the weighting factor generator 7-1 generates a weighting factor using the signal after A / D conversion and the despread signal for channel estimation for each path, and The despread signal of each reception antenna for each path is multiplied and weighted, and the weighted despread signal is synthesized by a synthesis unit to demodulate the signal.

The calculation of the weighting factor in the weighting factor generator 7-1 calculates the channel estimation value of each path based on the channel estimation despread signal of each path as shown in the flowchart of FIG. 8-1) Further, based on the despread signal for channel estimation of each path and the A / D converted signal, noise power including interference from neighboring cells and interference power from the own cell are obtained (step 8-). 2) Calculate weighting factors w _{n, 1} and w _{n, 2} using the following (Equation 5) (step 8-3).

[0053]

(Equation 5)

Here, b _{n, 1,1} , b _{n, 1,2} , b _{n, 2,1} ,
b _{n, 2,2} is the value obtained by the above (Equation 2). FIG. 9 shows an example of means for calculating the interference power 2σ _I ² Σ | α _i | ² and the noise power 2σ _N ² . The A / D conversion signal and the despread signal for channel estimation are input to the calculating means.
The power average of the D-converted signal (9-1), the power average of the channel estimation despread signal (9-2), and the square of the channel estimation average value (9-3) are calculated.

The power average of the A / D-converted signal is utilized by utilizing that the A / D-converted signal includes all spread components and the interference component of the despread signal includes components other than the components of the spread path. By subtracting the power (9-4) of the interference component of the despread signal from (9-1), the interference power (9-5) multiplied by the power of the channel estimation value of the path can be obtained.

Next, the power of the channel estimation value of all paths (9
−6) is calculated based on the power (9-3) of the channel estimation value of the path.
Channel estimation for all paths multiplied by reciprocal (9-7)
Multiply the constant power ratio (9-8) by the interference power (9-5)
Interference power 2σ_I ^TwoΣ ｜ α_i| ^TwoTo obtain the A / D conversion signal
From the power average (9-1) of the interference power 2σ_I ^TwoΣ ｜ α
_i|^TwoSubtract noise power 2σ_N ^TwoAsk for.

Further, in the embodiment shown in FIG. 7, the weight coefficient can be calculated in consideration of only the correlation of the interference component of the largest path according to the calculation flow shown in FIG. That is, the channel estimation value of each path is obtained from the despread signal for channel estimation of each channel (step 10-1), and the despread signal for channel estimation and the A / D converted signal are used to calculate The noise power including the interference and the interference power from the own cell are obtained (step 1).
0-2).

Next, a path in which the power of the channel estimation value (the total power of both antennas) is maximized is searched for (step 10-3). Then, the path information and the above step 1
From the noise power including interference from neighboring cells due to 0-2 and the interference power from the own cell, a weight coefficient is calculated using (Equation 5) (step 10-4). In this case, (Equation 5)
B _{n, 1,1} , b _{n, 1,2} , b _{n, 2,1} , b _{n, 2,2} b
_{, j, k} are values given by (Equation 4).

(Supplementary Note 1) In an antenna diversity receiving apparatus that receives a spread spectrum signal by two receiving antennas and despreads and combines a multipath signal at the same despread timing, a channel estimation value of each path is obtained.
Means for calculating a transform coefficient that eliminates the correlation of the interference signal between the two antennas based on the channel estimation value; and means for multiplying the signal after despreading by the transform coefficient to convert the signal into an uncorrelated signal of the interference signal. Combining means for combining a signal obtained by converting the interference signal into a signal having no correlation. (Supplementary Note 2) A unit for obtaining interference power of a channel estimation signal converted into a signal having no correlation of the interference signal, and calculating a weight coefficient from a channel estimation value normalized by the interference power, wherein the combining unit includes: 2. The antenna diversity receiving apparatus according to claim 1, wherein the weighted signal is multiplied by a signal obtained by converting the weight coefficient into a signal having no correlation with the interference signal to synthesize a weighted signal. (Supplementary Note 3) In an antenna diversity receiving apparatus that receives a spread spectrum signal by two receiving antennas and despreads and combines a multipath signal at the same despread timing, a channel estimation value of each path is obtained, and the channel estimation is performed. Means for calculating a transform coefficient for eliminating the correlation of the interference signal between the two antennas based on the values, and calculating noise power and interference power including interference from neighboring cells from the reception signals of both antennas and the despread signal for channel estimation Means for performing the conversion,
Means for calculating a weighting coefficient that maximizes the combined signal-to-interference power ratio based on the noise power and the interference power; and combining the weighted signal by multiplying the despread signal by the weighting coefficient to combine the weighted signal. And an antenna diversity receiving device. (Supplementary note 4) Any of the supplementary notes 1 to 3, wherein the means for calculating the transform coefficient calculates a transform coefficient that eliminates the correlation between the interference signals between the two antennas based on the channel estimation value of the largest path. An antenna diversity receiving apparatus according to any one of the above.

[0060]

As described above, according to the present invention,
In a mobile radio communication terminal device or the like in a spread spectrum mobile communication system, a signal power to interference power ratio (S) is obtained by performing conversion or weighting to eliminate correlation of interference components between diversity receiving antennas and combining them.
(IR) that maximizes antenna diversity reception.

[Brief description of the drawings]

FIG. 1 is a diagram showing main components of an antenna diversity receiving apparatus according to the present invention.

FIG. 2 is a diagram illustrating a specific example of removing interference in consideration of the correlation between antennas of an interference component according to the present invention.

FIG. 3 is a diagram showing an embodiment of the present invention that performs signal conversion that makes interference uncorrelated.

FIG. 4 is a flowchart of calculating a conversion coefficient in consideration of correlation of interference of all paths according to the present invention.

FIG. 5 is a flowchart of calculating a conversion coefficient in which only the correlation of the interference of the largest path is considered according to the present invention.

FIG. 6 is a diagram showing a configuration of a variable conversion unit according to the present invention.

FIG. 7 is a diagram illustrating an embodiment of the present invention in which weighting is performed such that interference is uncorrelated.

FIG. 8 is a flowchart of calculating a weight coefficient in consideration of correlation of interference of all paths according to the present invention.

FIG. 9 is a diagram showing a configuration of an interference power and noise power deriving unit used for calculating a weight coefficient according to the present invention.

FIG. 10 is a flowchart for calculating a weighting coefficient in consideration of only the correlation of the interference of the largest path according to the present invention.

FIG. 11 is a diagram illustrating a signal combining unit of a conventional antenna diversity receiving apparatus.

FIG. 12 is a diagram illustrating a configuration example of a conventional weight coefficient calculation unit.

FIG. 13 is a diagram illustrating a relationship between a propagation environment and despreading timing of antenna diversity reception.

[Description of Signs] 1-1 First Antenna 1-2 Second Antenna 1-11, 1-21 Radio Receiver 1-12, 1-22 Analog / Digital (A / D)
Transformer 1-3 Searcher 1-4 Despreading unit 1-5 Transformation coefficient / weight coefficient generation unit 1-6 Signal conversion / combination unit 1-7 Signal processing unit 1-8 Transmission unit 1-9 Antenna duplexer

Claims (3)

[Claims] 1. An antenna diversity receiving apparatus for receiving a spread spectrum signal by two receiving antennas and despreading and combining a multipath signal at the same despread timing, obtains a channel estimation value of each path, Means for calculating a transform coefficient for eliminating the correlation of the interference signal between the two antennas based on the estimated value; means for multiplying the despread signal by the transform coefficient to convert the signal into a signal having no correlation of the interference signal; Means for synthesizing a signal after conversion into an uncorrelated signal of an interference signal. 2. An antenna diversity receiving apparatus for receiving a spread spectrum signal by two receiving antennas and despreading and combining a multipath signal at the same despread timing, obtains a channel estimation value of each path, Means for calculating a transform coefficient that eliminates the correlation of the interference signal between the two antennas based on the estimated value, and, from the received signals of both antennas and the despread signal for channel estimation, the noise power and interference power including interference from neighboring cells Means for calculating, a means for calculating, based on the conversion coefficient, noise power and interference power, a weight coefficient that maximizes the combined signal-to-interference power ratio, and multiplying the weighted coefficient by the despread signal. And a combining means for combining the signals weighted by weighting. 3. The transform coefficient calculating unit calculates a transform coefficient that eliminates a correlation between interference signals between the two antennas, based on a channel estimation value of a largest path. An antenna diversity receiving device according to item 1.