JPH03278723A - Data receiver - Google Patents

Abstract

PURPOSE:To attain equalization without deterioration in the effect even when a line impulse response is fluctuated with time by using an impulse response estimate circuit receiving plural sets of impulse response so as to estimate sequentially the impulse response at an optional time. CONSTITUTION:An impulse response estimate circuit 18 consists of a differentiating value calculation device 13, an adder 14, a weighting device 15 and a delay device 16. Then the calculation device 13 uses an estimate value 22 to calculate differentiating values 23-0, 1, M1, the obtained differentiating values are weighted by weighting devices 15-0, 1, M1, added by an adder 14, from which a new index pulse response is obtained and stored in delay devices 16-1, M1. The complex number index pulse response is obtained at an optional time even when line fluctuation exists, and an equalizer 19 uses the information to carry out equalization. Thus, even when the line impulse response is fluctuated, the effect of equalization is not deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a data receiving device used in digital mobile communications and the like.

Conventional technologyDigital data communication devices have become widely used in recent years because they can perform so-called signal equalization, which compensates for signal waveform distortion on the receiving side, and thereby achieve high fidelity. It has become.

Hereinafter, a conventional data receiving device of this type will be explained based on the drawings.

FIG. 2 is a block diagram showing a schematic configuration of a conventional data receiving device. In FIG. 2, 1 is an input terminal of the received signal, 2 is an impulse response estimator connected to the input terminal 1,
3 is an equalizer to which the input terminal 1 and the output side of the impulse response estimator 2 are connected, and 4 is an output terminal to which the demodulated signal from the equalizer 3 is output.

Next, the operation of the above conventional example will be explained. In FIG. 2, an impulse response estimator 2 estimates the complex impulse response of the line from known signals included in the received signal input to the input terminal 1, and provides this information to an equalizer 3. The equalizer 3 equalizes the received signal based on this given information, thereby eliminating deterioration caused by frequency selective fading, etc., and creating a demodulated signal with a lower error rate than when the received signal is demodulated as is. is output to output terminal 4.

In this way, even in the conventional data receiving apparatus, the impulse response estimator 2 calculates the complex impulses of the line.

Since it is possible to estimate the impulse response of the line and use that information, if there is no fluctuation in the impulse response of the line, it is possible to remove deterioration caused by frequency selective fading, etc., and obtain a demodulated signal with a good error rate. .

Problems to be Solved by the Invention However, once the impulse response is estimated in the conventional data receiving device described above, it is difficult to equalize signals at a different time point from the point at which the impulse response was estimated using the initially estimated impulse response. Therefore, if the impulse response of the line fluctuates, there is a problem that the equalization effect deteriorates.

The present invention solves these conventional problems,
It is an object of the present invention to provide an excellent data receiving device that can prevent the equalization effect from deteriorating even if the impulse response of a line varies.

In order to achieve the above object, the present invention provides a plurality of impulse response estimators for obtaining a plurality of impulse responses at different times, and a plurality of impulse response estimators obtained by the plurality of impulse response estimators. The configuration includes an impulse response estimating circuit that estimates an impulse response at an arbitrary point in time from the impulse response of , and an equalizer that equalizes the impulse response estimated by the impulse response estimating circuit.

Therefore, according to the present invention, a plurality of impulse responses at different time points can be estimated by a plurality of impulse response estimators, and an impulse response estimation circuit that inputs the plurality of impulse responses can sequentially estimate the impulse response at an arbitrary time point. By doing so, it is possible to eliminate deterioration of the equalization effect even if the impulse response of the line fluctuates.

Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a data receiving apparatus according to an embodiment of the present invention. In FIG. 1, 11 is an input terminal for a received signal; 12. O~12, M-1 are a plurality of impulse response estimators connected to the input terminal 11, 13
is a differential value calculator, 14 is a multiple weighting device 15, 0 to 1
5. A plurality of adders 16,1 to 16. connected to the output side of the differential value calculator 13 via M-1. M-1 is a delay device,
17, O~17. M-1 is a changeover switch.

Especially the changeover switch 17,0-17. M-2 are impulse response estimators 12, 0 to 121M-2 and delay unit 1, respectively.
6,1-16. M-2 and changeover switch 17.
M-1 is an impulse response estimator 12. M-1 and adder 1
These changeover switches 17,
0 to 17°M-1 is connected to the input side of the differential value calculator 13.

The differential value calculator 13, the adder 14, and the weighting units 15,0 to 15. M-1, delay devices 16.1 to 16. M
-1, selector switch 17. An impulse response estimation circuit 18 is configured by O to 17 and M-1.

19 is an input terminal 11 and a changeover switch 17. 20 is an output terminal from which a demodulated signal is output from the isoflower vase 19.

Next, the operation of the above embodiment will be explained. In the above embodiment, a plurality of impulse response estimators 12
．． O~12. M-11:: Estimate the complex impulse response of the line at the shifted time and convert them into h(0; n
), h(1; n), ・−, h(M 1 ; n) where n is the number of the impulse response), h'(t ; n) = ((t +1 ; n) −h
Considering (t; n))/1, h''(t;n)=I(-1)''-' C = 0
11 xh( can be expressed as 10m-i;n)-(I). Here, when performing Taylor expansion of h(t;n) up to the M-1 order term, xl/j! becomes. Therefore, if a = t - M, then XI/j
! ; Since t>M...(H), the complex impulse response h(t;n) at any time is h(t-M
an), h'(t-M; C11-1) n), h (t-Man), -, h (t
-M;n), that is, h(t-1;n), h(
It can be expressed as t-2;n), =-, h(t-Man). That is, since h(0;n) to h(M-1;h) have been found, h(M;n), h(M+1;n),
... is found.

In Fig. 1, h(0;n) is the initial value (21°O),
h(1;n) is the initial value (21,i), h(M-1;n)
is initially [(21,M-1)T:ji>ru. Changeover switch 17. o~17. M-] is terminal A only at the very beginning of estimation.

- AM-1 side, initial value (21,○~21.M
-1) becomes the estimated value 22, and at the same time the delay device 16, 1 to 1
6. It is input to M-1.

The differential value calculator 13 uses the estimated value 22 and calculates the differential values 23,0 to 23. Calculate M-1 and obtain the differential 11!23.0~23. M-1 is the above (II
) The weighting is done by 15° to 15° so as to satisfy the equation. M-
The signals are weighted by 1 and added together in an adder 14 to obtain a new index pulse response.

This value is sent to adder 14, terminal B. - Selector switch 17, 0 to 1' turned on the BM-1 side? , M-1, delay units 16,1-16. (Each time a new index pulse response is determined, the oldest one is emitted and a new one is stored, always storing M-1 index pulse responses.)

By repeating this, the complex index pulse response at any point in time can be found even when there are line fluctuations.
The equalizer 19 uses the information to perform equalization.

In this way, in the above embodiment, since the index pulse response at any point in time can be estimated, by performing equalization using this, it is possible to obtain a demodulated signal with good error rate characteristics even when there are line fluctuations. It has the advantage of being able to

In the above embodiment, the complex impulse response was directly estimated, but the complex impulse response was estimated as follows: h(t;n)-hi(t;n)+jh
(t; n), and the real part h i (t ; n) and the imaginary part h9 (t ; n) may be estimated independently. In this case, the configuration and operation are similar to those of the above embodiment.

Also, considering the complex impulse response as, the vibrational component (tan) and the phase component θ(jan)
It may be divided into 2 and estimated independently. In this case as well, the configuration and operation are the same as in the above embodiment.

Effects of the Invention As described above, according to the present invention, there are provided a plurality of impulse response estimators for obtaining a plurality of impulse responses at different points in time, and an arbitrary number of impulse responses obtained by the plurality of impulse response estimators. an impulse response estimation circuit that estimates an impulse response at a point in time;
Since the configuration is equipped with an equalizer that performs equalization using the impulse response estimated by this impulse response estimation circuit, the complex impulse response of the line at any point in time can be estimated, and the equalization is performed using this complex impulse response. By doing so, even when the impulse response of the line fluctuates, the deterioration of the equalization effect can be suppressed and a good error rate can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a data receiving device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of a conventional data receiving device. 12, o~12. M-1...impulse response estimator,
18... Impulse response estimation circuit, 19... etc. Flower vase.

Claims (1)

[Claims] A plurality of impulse response estimators that obtain a plurality of impulse responses at different times; an impulse response estimation circuit that estimates an impulse response at any time from the plurality of impulse responses obtained by the plurality of impulse response estimators; A data receiving device comprising an equalizer that performs equalization using an impulse response estimated by a response estimation circuit.