JP3414361B2 - Receiving device and receiving method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving apparatus and a receiving method for data communication for adaptively controlling the weight of a receiving system of an antenna having a plurality of elements.

[0002]

2. Description of the Related Art Conventionally, as a receiver for data communication, a receiver having a plurality of antenna elements has been devised.
In this type of device, the gain of the direction of arrival of the radio wave is increased, the gain of the direction of the interference signal is decreased, and the phase and amplitude of the signal data of each element are multiplied by the weight so that only the desired signal is received. The control method is adopted.

FIG. 2 shows an example of a receiving apparatus in the case of being composed of N antenna elements. Signal data of each element (first to Nth element signal data) is complex data obtained by A / D converting the I signal and the Q signal after quadrature detection after passing through the analog section of the receiving device from each antenna element (I (Signal is real part, Q signal is imaginary part).

In the case of spread spectrum communication, the signal data is despread after A / D conversion, but there is no difference in processing in the configuration of FIG. The signal data of each element of the reception system is subjected to complex multiplication by the multipliers 2-1 to 2-N by the weight corresponding to each element output from the weight control section 1, and further combined by the combining section 3. Here, “synthesize” means mathematically perform complex addition. In this case, since the initial value of the weight cannot be calculated, only one element is 1 (real part is 1, imaginary part is 0), and the rest is 0 (real part is 0, imaginary part is 0). It is given to the weight control unit 1 by, for example.

Usually, the signal data is composed of a part of pilot data of a fixed data array known to the receiving side and a part of actual communication data unknown to the receiving side,
The alternating array units are continuous.

The channel estimation unit 4 sequentially compares the received pilot data portion with known pilot data stored in the memory, and further averages them to detect a phase shift. The phase shift is called a channel estimation value because it is influenced by the transmission path, but it is mathematically obtained by multiplying the received pilot data by the complex conjugate of the known pilot data.

The complex conjugate of the channel estimation value is multiplied by the multiplier 5
When the communication data is multiplied by, demodulated data of the communication data is obtained. Here, to the multiplier 5, the signal data synthesized by the synthesis unit 3 delayed by the delay unit 7 is given.

Finally, the demodulated data is demodulated into data of 1 or 0 by phase judgment. For example BPS
For K modulation, there are binary values of 1 and 0, and for QPSK modulation, there are four values of 00, 01, 10, 11. On the other hand, for the received pilot data, the complex conjugate of the channel estimation value is multiplied by the multiplier 5 and the difference from the pilot data is obtained by the adder 6, so that the weight controller 1 calculates the weight. Used for.

This difference represents an error. A method of controlling weights based on the error signal is called adaptive weight control based on a minimum-mean-squared-error (MMSE) standard. In the weight control unit 1,
The weights are optimized and updated based on the signal data of each element and the error signal before weight multiplication. Weight control unit 1
Then, the weights are optimized and updated on the basis of the signal data of each element before weight multiplication multiplied by the channel estimation value and the error signal.

Incidentally, as typical adaptive weight control algorithms, there are LMS algorithm and RLS algorithm. The weight control unit 1 gradually changes from the initial weight toward the optimum weight each time one pilot data is obtained, and finally converges to the optimum weight.

[0011]

By the way, in the above-mentioned conventional receiver for data communication, since the weight rapidly changes after the receiver is started and before the weight converges, the channel estimation unit 4 There is a problem that the phase shifts during averaging the phase, and an error occurs in the calculation of the channel estimation value, so that the demodulation error finally increases.

The present invention has been made in view of such a situation, and reduces the error in the calculation of the channel estimation value until the weight converges after the startup of the device, and finally the demodulation error. It is possible to provide a receiving apparatus and a receiving method capable of reducing the number of noises.

[0013]

According to a first aspect of the present invention, there is provided a receiving device for adaptively controlling a weight from a weight control unit of a receiving system of an antenna having a plurality of elements. The phase is detected from the first multiplier that performs the complex multiplication of the signal data of each element by the weight corresponding to each element output from the weight control section, and the weight of the reference element obtained by the weight control section. A phase correction calculation unit that calculates a phase correction coefficient that cancels the phase shift, and a second multiplier that multiplies the phase correction coefficient calculated by the phase correction calculation unit and gives it to the first multiplier. , A part of the received pilot data and the known pilot data stored in the memory are sequentially compared, and further averaged to detect a phase shift, and a channel estimation part to be given to the weight control part. Characterized in that it comprises. The first multiplier may be provided corresponding to the signal data of each element of the reception system, and the second multiplier may be provided corresponding to the first multiplier. it can.
Further, the phase correction calculation unit detects the phase of the weight from the weight control unit with respect to the reference element, in symbol units, and sets the reference element weight to the same real part 1 and imaginary part 0 as the initial weight. If you always want a value,
It is possible to use a value obtained by complexly dividing the real part 1 and the imaginary part 0 by the detected phase as the phase correction coefficient. The receiving method according to claim 4 is a receiving method for adaptively controlling a weight from a weight control unit of a receiving system of an antenna having a plurality of elements, wherein each element of the receiving system is controlled by the first multiplier. The first step of complexly multiplying the signal data of 1) by the weight corresponding to each element output from the weight control section, and the phase correction calculation section from the weight for the reference element obtained by the weight control section to the phase Is detected and a phase correction coefficient for canceling the phase shift is calculated, and a second multiplier multiplies the phase correction coefficient calculated by the phase correction calculation unit to obtain a first phase correction coefficient. The third step applied to the multiplier and the channel estimation unit sequentially compare the received pilot data portion with the known pilot data stored in the memory, and further average and dephase. Characterized in that it comprises a fourth step of providing the wait control unit detects a. Further, the first step includes a fifth step in which the first multiplier is provided corresponding to the signal data of each element of the reception system, and the third step includes
A sixth step of providing the second multiplier corresponding to the first multiplier may be included. In the second step, the sixth step of detecting the phase of the weight from the weight control unit in symbol units for the reference element, and the real part 1 in which the reference element weight is the same as the initial weight, If it is desired to always use the reference value of the imaginary part 0, it is possible to include a seventh step in which the real part 1 and the imaginary part 0 are subjected to complex division by the detected phase as a phase correction coefficient. In the receiving device and the receiving method according to the present invention, the signal data of each element of the receiving system is complex-multiplied by the weight corresponding to each element output from the weight controller by the first multiplier, and the phase correction calculation is performed. Section detects a phase from the weight of the reference element obtained by the weight control section, calculates a phase correction coefficient that cancels the phase shift, and the second multiplier calculates the phase correction calculation section. Is multiplied by the phase correction coefficient and given to the first multiplier, and the channel estimation unit sequentially compares the received pilot data portion with the known pilot data stored in the memory, and By averaging and detecting the phase shift and applying it to the weight controller, the phase of the element serving as the weight reference is always constant.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIG. 1 is a diagram showing an embodiment of a receiving apparatus of the present invention. In the drawings described below, the same parts as those in FIG. 2 are designated by the same reference numerals.

The receiver of FIG. 1 includes a weight control unit 1, multipliers (first to Nth elements) 2-1 to 2-N, a combining unit 3, a channel estimating unit 4, a multiplier 5, an adder 6, Delay unit 7,
Phase correction coefficient calculation unit 8, multiplier (first to N-th element) 9-
1-9-N.

The weight control unit 1 optimizes and updates the weight based on the signal data of each element and the error signal before the weight multiplication.

Multipliers 2-1 to 2- serving as first multipliers
N performs complex multiplication of the signal data of each element of the reception system by the weight corresponding to each element output from the weight control unit 1. The combining unit 3 combines the outputs of the multipliers 2-1 to 2-N and the multipliers 9-1 to 9-N.

The channel estimation unit 4 sequentially compares the received pilot data portion with the known pilot data stored in the memory, and further averages them to detect a phase shift. The multiplier 5 obtains demodulation data of the communication data by multiplying the communication data by the complex conjugate of the channel estimation value.

The adder 6 takes the difference from the received pilot data and gives it to the weight controller 1. Delay section 7
Delays the output from the combining unit 3. The phase correction coefficient calculation unit 8 uses the weight control unit 1 for the reference element.
The phase of the weight obtained in step 1 is detected in symbol units.
That is, the phase correction coefficient from the weight control unit 1 to the phase correction coefficient calculation unit 8 is given only by the first element signal data.

Multipliers 9-1 to 9- serving as second multipliers
N multiplies the weight of each element by the phase correction coefficient.

Next, the operation of the receiving apparatus having such a configuration will be described.

First, the signal data of each element (first to Nth element signal data) passes from each antenna element through the analog portion of the receiving device, and after quadrature detection, the I signal and the Q signal are A / D converted. As complex data (I signal is a real part and Q signal is an imaginary part), it is taken into each of the multipliers 2-1 to 2-N.

At this time, the multipliers 2-1 to 2- are operated by the weights corresponding to the respective elements output from the weight controller 1.
It is subjected to complex multiplication by N and further combined in the combining unit 3. In this case, as described above, the initial value of the weight is 1 for only one element (the real part is 1, the imaginary part is 0), and the rest are all 0.
(The real part is 0 and the imaginary part is 0).

At this time, the phase correction calculation unit 8 detects the phase of the weight obtained by the weight control unit 1 for each reference element in symbol units. Here, the phase correction coefficient from the weight controller 1 to the phase correction coefficient calculator 8 is given only by the first element signal data. That is, for example, when it is desired to always set the weight of the reference element to the reference value of the real part 1 and the imaginary part 0, which are the same as the initial weight, a complex division by the detected phase of the real part 1 and the imaginary part 0 is defined as a phase correction coefficient To do.

The phase correction coefficient from the phase correction calculation unit 8 is
By being given to the multipliers 9-1 to 9-N, the weight of each element is multiplied by the phase correction coefficient. Also, the multiplier 9-
The outputs from 1 to 9-N correspond to the corresponding multipliers 2-
1 to 2-N.

As a result, the relationship between the amplitude and the phase between the elements does not change, and the weight of the reference element is always the real part 1,
The imaginary part becomes 0. As a result, the error in the calculation of the channel estimation value after the start-up of the receiving device until the weight converges is reduced, and finally the demodulation error is reduced.

Here, in the initial weight, usually, the amplitude of the weight of the element serving as the reference of the weight is 1 and the amplitude of the weight of the other elements is 0. , The ratio given to the channel estimation of the phase of the reference weight is large.

Further, the channel estimation unit 4 sequentially compares the received pilot data portion with the known pilot data stored in the memory, and further averages them to detect a phase shift. The phase shift is obtained by multiplying pilot data by the complex conjugate of known pilot data.

The multiplier 5 multiplies the communication data by the complex conjugate of the channel estimation value to obtain demodulated data of the communication data. Here, to the multiplier 5, the signal data synthesized by the synthesis unit 3 delayed by the delay unit 7 is given.

As described above, in the present embodiment, the multiplier 2
The signal data of each element of the receiving system is
Complex multiplication is performed by the weight corresponding to each element output from the weight control unit 1, and the phase correction calculation unit 8 detects the phase from the weight of the reference element obtained by the weight control unit 1 and calculates the phase A phase correction coefficient that cancels the shift is calculated, and the multipliers 9-1 to 9-N calculate
The phase correction coefficient calculated by the phase correction calculation unit 8 is multiplied and given to the multipliers 2-1 to 2-N, and the channel estimation unit 4 stores the portion of the received pilot data and the known value stored in the memory. Since the phase of the element serving as a weight reference is always constant, the phase difference of the weight is detected by the weight control unit 1 by comparing the pilot data sequentially with the pilot data of FIG. By the time the weights converge, the error in the calculation of the channel estimation value can be reduced, and finally the demodulation error can be reduced.

That is, the initial value of the weight is that the amplitude of the reference element is 1 and the rest is 0. Therefore, in the process until convergence, the phase shift of the reference element becomes the absolute phase after combination. It will have a great impact. In the convergence process, the weight of the reference element also shifts, and as a result, the absolute phase also shifts. Therefore, the demodulation error is reduced by eliminating the absolute phase shift between the symbols.

Incidentally, since the amplitude and phase correction amount is calculated with reference to the amplitude and phase of the reference element and the same amplitude and phase correction is made for all the elements, the relative amplitude and phase between the elements do not change. .

Further, in the present embodiment, since the adaptive weight control algorithm such as RLS is provided and the weight considering the relative phase difference between the elements is calculated, the relative phase difference between the elements is completely different. There is no need to make corrections with the function.

In this embodiment, the case where the delayed waves due to the multipath are processed without considering for the sake of simplicity has been described, but the same processing as this example is performed for the number of delayed waves due to the multipath. , Finally, multi-pass synthesis can be performed. This multipath combining is called RAKE combining. Basically, delay waves due to multipath can be taken into consideration by arranging the configuration of FIG. 1 in parallel by the number of multipaths.

[0036]

As described above, according to the receiving apparatus and the receiving method of the present invention, the signal data of each element of the receiving system is made to correspond to each element output from the weight controller by the first multiplier. A complex multiplication is performed using the weights, the phase correction calculation unit detects the phase from the weights of the reference elements obtained by the weight control unit, and calculates a phase correction coefficient that cancels the phase shift. Of the phase correction coefficient calculated by the phase correction calculation unit and applied to the first multiplier, and the channel estimation unit calculates a portion of the received pilot data and a known value stored in the memory. The phase is compared with the pilot data sequentially, and the average is further detected to detect the phase shift and given to the weight control unit so that the phase of the element serving as the weight reference is always constant. It can be reduced after startup of the apparatus, weights and reduce the error in the calculation of the channel estimation values until convergence, the final demodulation errors.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a receiving apparatus of the present invention.

FIG. 2 is a diagram showing an example of a conventional receiving device. And reception method

[Explanation of symbols]

1 Weight control unit 2-1 to 2-N Multiplier (First to Nth Element) 3 Composition Department 4-channel estimator 5 multiplier 6 adder 7 Delay section 8 Phase correction coefficient calculator 9-1 to 9-N multiplier (first to N-th element)

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) H04B ⁷ /02-7/12 H04L 1/02-1/06 H01Q 3/00-3/46 H01Q 21 / 00-25/04

Claims (6)

(57) [Claims] 1. A receiver for adaptively controlling a weight from a weight control unit of a reception system of an antenna having a plurality of elements, wherein signal data of each element of the reception system is output from the weight control unit. And a first multiplier for performing complex multiplication with a weight corresponding to each element, and a phase correction for detecting a phase from the weight for the reference element obtained by the weight control unit and canceling the phase shift. A phase correction calculation unit that calculates a coefficient, a second multiplier that multiplies the phase correction coefficient calculated by the phase correction calculation unit and gives the first multiplier, a portion of received pilot data, and a memory. And a channel estimation section for sequentially comparing the known pilot data stored in the above, detecting the phase shift by further averaging, and providing the weight control section with the channel estimation section. That the receiving device. 2. The first multiplier is provided corresponding to signal data of each element of a reception system, and the second multiplier is provided corresponding to the first multiplier. The receiving device according to claim 1, wherein the receiving device is provided. 3. The phase correction calculation unit detects the phase of the weight from the weight control unit with respect to the reference element in symbol units, and the weight of the reference element is the same as the real part 1, which is the initial weight. The receiving apparatus according to claim 1, wherein, when it is desired to always set the reference value of the imaginary part 0, the real part 1 and the imaginary part 0 are complexly divided by the detected phase to be used as a phase correction coefficient. 4. A receiving method for adaptively controlling a weight from a weight control unit of a receiving system of an antenna having a plurality of elements, wherein signal data of each element of the receiving system is converted by a first multiplier,
The first step of performing complex multiplication by the weight corresponding to each element output from the weight control section, and the phase correction calculation section to detect the phase from the weight for the reference element obtained by the weight control section. ,
A second step of calculating a phase correction coefficient that cancels the phase shift, and a second multiplier that multiplies the phase correction coefficient calculated by the phase correction calculation unit to obtain the first multiplier. And the channel estimation section sequentially compares the received pilot data portion with the known pilot data stored in the memory, and further averages them to detect a phase shift and perform the weight control. And a fourth step of giving the section. 5. The first step includes a fifth step of providing the first multiplier in correspondence with signal data of each element of a reception system, and the third step includes The receiving method according to claim 4, further comprising a sixth step of providing the second multiplier corresponding to the first multiplier. 6. In the second step, a sixth step of detecting a phase of a weight from the weight control unit for each reference element in a symbol unit, and a weight of the reference element as an initial weight If you always want to use the same reference value for real part 1 and imaginary part 0, real part 1 and imaginary part 0
7. The receiving method according to claim 4, further comprising a seventh step of using a value obtained by complexly dividing the detected phase as a phase correction coefficient.