JPH10322320A - Maximum ratio synthesis diversity receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the maximum ratio synthesis diversity not using a memory. SOLUTION: The receiver is made up of an input means consisting of phase detection means 1, 2, delay means 3, 4 and adder means 5, 6 that calculates phase data from data received from pluralities of reception systems of different transmission lines and receives the data, cosine/sine approximation means 9, 10, 11, 12 that calculate cosine/sine data from the received phase data, weighting coefficient approximation means 7, 8 that calculate a weighting coefficient from reception level information obtained from the reception system and provide an output of the coefficient, multipliers 13-16 that use the weighting coefficient outputted by the weighting coefficient approximation means 7, 8 to apply the cosine/sine data calculated by the cosine/sine approximation means 9, 10, 11, 12, adders 17, 18 that synthesize the weighted cosine/sine data to produce synthesis data, and a decoding means 19 that decodes the synthesis data to provide an output of a decoding signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maximum ratio combining diversity receiver for converting a received signal in a wireless communication device into a digital value and performing maximum ratio combining.

[0002]

2. Description of the Related Art It is known that the receiving performance of a radio communication device is significantly deteriorated by the fading phenomenon in which the receiving performance fluctuates drastically due to reflection and scattering of radio waves.

Conventionally, as an effective means for compensating for a decrease in reception level due to such a fading phenomenon, reception is performed using a plurality of reception systems, and each reception system signal is weighted according to the reception level. The maximum ratio combining method is used.

As an apparatus for realizing the maximum ratio combining method, a memory for outputting a product of the reception level or the square of the reception level data and the cosine (I component) of the reception phase and the reception level data or the square of the reception level data are used. A maximum ratio combining diversity receiver using a memory that outputs a product of the sine (Q component) of the reception phase and a small digital line is known together with these memories (for example, Japanese Patent Application Laid-Open No. 7-307724). ).

FIG. 5 shows an example of such a conventional maximum ratio combining diversity receiver, which is configured to combine two systems of received signals. For this device,
The phase detectors 3 and 4 detect the phases of the received signals input from the input terminals 1 and 2, delay the detected phase by one symbol time by the delay units 5 and 6, and receive by the adding units 7 and 8. By detecting a signal difference, delay detection for detecting a phase change between one symbol is performed. Then, the first storage means 9, 11 are obtained from the respective phase data and the received data information (RSSI) output by the addition means 7, 8.
Outputs the product of the square of the reception level data and the I component of the reception phase data.

Further, the second storage means 10 and 12 output the product of the square of the received level data and the Q component of the received phase data. As a result, the I component and the Q component of the phase data are calculated and weighted, and are combined by the adders 13 and 14, respectively, and decoded by the decoding unit 15, thereby achieving maximum ratio combining.

[0007]

However, according to the conventional maximum ratio combining diversity receiver described above, the reception level data and the reception phase data relating to the magnitude of the reception signal are input, and the reception data or the reception level data is received. First storage means for outputting the product of the square and the sine of the received phase data, or the input of the received level data and the received phase phase data and the reception level data or the square of the received level data and the cosine of the received phase data In order to use a storage device as a memory, such as a second storage unit that outputs a product, the number of gates is inevitably increased when a single chip or the like is performed, which causes a cost increase.

[0008] The present invention is directed to such a conventional technique.
It is an object of the present invention to provide a diversity receiver capable of performing maximum ratio combining without using a storage device such as a memory which causes an increase in cost.

[0009]

According to the present invention, in order to achieve the above object, each phase data and reception level information (RS
When deriving the product of the square of the reception level data and the sine and cosine of the reception phase data from SI), the generation equation is performed using an approximate expression such as a straight line, so that general shift registers, selectors, and multipliers can be used. The maximum ratio combining is realized without using any storage means by using only a hard logic.

[0010]

A maximum ratio combining diversity receiving apparatus according to the present invention calculates reception phase data from reception data received from a plurality of reception systems having different transmission lines in a radio communication device. Input means, a cosine conversion means for calculating a cosine from the phase data input to the input means, a sine conversion means for calculating a sine from the phase data input to the input means, and a signal obtained from the receiving system. Weighting coefficient conversion means for calculating and outputting a weighting coefficient from the received reception level information, and the cosine or sine calculated by the cosine conversion means and the sine conversion means,
Weighting means for weighting using the weighting coefficients output by the weighting coefficient conversion means, synthesizing means for synthesizing cosine or sine weighted by the weighting means to generate synthesized data, and synthesizing means generated by the synthesizing means Decoding means for decoding data and outputting a decoded signal.

As a result, the maximum ratio combining diversity receiver according to the present invention detects each received signal,
In order to calculate the Q component, cosine and sine conversion are performed using cosine conversion means and sine conversion means. At this time, cosine and sine conversion in which the cosine and sine are approximated by a straight line or the like is performed. Further, when weighting coefficient conversion is performed from the reception level information (RSSI) by using weighting coefficient conversion means, the weighting coefficient conversion is also performed using approximate weighting coefficients such as straight lines. For conversion of these approximated straight lines or the like, the weighting coefficient conversion means can use simple hardware logic such as an adder and a multiplier.

Next, the weighting means calculates the cosine or sine calculated by the cosine conversion means and the sine conversion means,
Weighting is performed using the weighting coefficient output from the weighting coefficient conversion means. This weighting means can be constituted by a multiplier.

Next, the combining means combines the cosine or sine weighted by the weighting means to generate combined data. This combining means can be constituted by an adder.

The combined data combined by the combining means is decoded by the decoding means.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience of explanation, a case is described in which the wireless communication device has two transmission lines as an example, but the present invention is not limited to this, and m transmission lines (m is an integer)
It does not matter.

In FIG. 1, reference numerals 1 and 2 denote phase detecting means,
3, 4 are delay means, 5, 6 are addition means, 7, 8 are weighting coefficient approximation means as weighting coefficient conversion means, 9, 1
0 is cosine approximation means as cosine conversion means, 11 and 12 are sine approximation means as sine conversion means, 13, 14, 1
5 and 16 are multipliers, 17 and 18 are adders, and 19 is decoding means.

The phase of the received signal is detected by the phase detection means 1 and 2 of each reception system, and the detected phase is delayed by the delay means 3 and 4.
Thereby delaying one symbol. Then, the adding means 5 and 6 detect the difference between the detected phases, thereby performing the delay detection for detecting the phase change amount θ between one symbol.

Then, from the detected phase change θ, I
Component and Q component, cosine approximation means 9 and 10, sine approximation means 1
Calculated in steps 1 and 12 and converted from reception level information (RSSI) into weighting coefficients by weighting coefficient approximation means 7 and 8.

As this conversion method, for example, the I component
FIG. 2 in which the COS value is approximated by a straight line, FIG. 3 in which the COS value is approximated by a SIN value, and {10} in order to obtain a square weighting coefficient from the reception level information (RSSI)
^{(RSSI [dBu]) / 20} ｝ ² is converted as shown in FIG.

First, as shown in FIGS. 2 and 3, when the I component and the Q component are calculated, the slope is set to 2
ⁿ (n is an integer), the generation equation is 2 ⁿ × θ + A
(A is an integer), and can be configured with a logic circuit that is easy to use as a shift register and an adder.

Next, as shown in FIG. 4, the weighting coefficient is the square of the received level information {10 ^{(RSSI [dBu]) / 20} } ²
Equation (2 ⁿ × RSSI + B (B is an integer)) obtained by linearly approximating can be similarly configured by a general logic circuit.

Then, the I component, which is approximately converted,
The Q component and the weighting coefficient are multiplied by multipliers 13, 14, 15, and 16 as weighting means, and I components and Q components are respectively synthesized by adders 17 and 18 as synthesis means.

The I component and the Q component combined in this way are decoded by the decoding means 19 and maximum ratio combination is performed.

The hardware configuration of each block may be constituted by equivalent software.
Further, in the above description, for simplicity, a linear approximation having a slope of 2 ⁿ is used, but any other approximation may be used.

[0025]

As described above, according to the present invention, a performance almost equal to that of the maximum ratio combining diversity receiver having a storage device such as a memory can be easily constituted only by hardware logic, and the storage device such as a memory can be used. Because it does not, the cost can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a maximum ratio combining diversity receiving apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a phase amount θ and an I component by cosine approximation means;

FIG. 3 is a diagram showing a relationship between a phase amount θ and a Q component by sine approximation means;

FIG. 4 shows the reception level (RS
Diagram showing the relationship between SI) and weighting factors

FIG. 5 is a configuration diagram of a conventional maximum ratio combining diversity receiver.

[Explanation of symbols]

1, 2 phase detection means 3, 4 delay means 5, 6 addition means 7, 8 weighting coefficient approximation means (weighting coefficient means) 9, 10 cosine approximation means (cosine conversion means) 11, 12 sine approximation means (sine conversion means) 13,14,15,16 Multipliers (weighting means) 17, 18 Adders (synthesis means) 19 Decoding means

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobumoto Kasahara 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Matsushita Communication Industrial Co., Ltd.

Claims (1)

[Claims] 1. An input means for calculating and inputting received phase data from received data respectively received from a plurality of receiving systems having different transmission lines in a wireless communication device, and calculating a cosine from the received phase data input to the input means. Cosine conversion means for calculating, sine conversion means for calculating a sine from reception phase data input to the input means, and weighting coefficient means for calculating and outputting a weighting coefficient from reception level information obtained from the reception system. Weighting means for weighting the cosine or sine calculated by the cosine conversion means and sine conversion means using the weighting factor output by the weighting coefficient conversion means; and combining the cosine or sine weighted by the weighting means. Combining means for generating combined data; decoding the combined data generated by the combining / generating means; And decoding means for outputting a decoded signal.