JPH02137526A - Data transmitter - Google Patents

Abstract

PURPOSE:To eliminate distortion due to a delay wave and distortion due to adjacent channel interference effectively by equalizing a reception signal with a tap coefficient of an equivalent device obtained from the reception signal at a comparatively long time interval and the tap coefficient at a comparatively shorter time interval with an interpolation polynomial. CONSTITUTION:A coefficient setting device 7 at a receiver side fetches a reference signal data for each time interval to set a tap coefficient string of a fraction interval equalizer 8 for each time interval T/n from a detector 6, and the information data for each time interval T/n from the detector 6 is fetched by the equalizer 8, to apply equalization by the tap coefficient set by the coefficient setting device 7. Thus, a fraction interval equalizer 8 having a coefficient for each time interval T is expanded into an equalizer having a coefficient for each time interval T/n, then the range of the signal frequency processed by the equalizer 8 is increased and then the distortion due to a delay wave and the distortion due to the interference from the adjacent channel are eliminated.

Description

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

Conventional technology FIG. 4 shows the configuration of a conventional data transmission device.

FIG. 5 shows a detailed configuration of the coefficient setter shown in FIG. It is configured to radio-frequency amplify the signal and transmit it wirelessly via the antenna 32.

Similarly, as shown in Figure 3, the data transmitted from the transmitting side consists of a frame consisting of reference signal data and information data, and on the receiving side, the rare fish signal data is known and the information data is unknown.

On the receiving side, when a radio signal from the transmitting side is received via the antenna 33, the amplifier 34 amplifies the received signal at high frequency, and the detector 35 synchronously detects this high frequency signal and converts it into a baseband signal.

This baseband signal is a signal that has been distorted by the wireless transmission path.

36 is a coefficient setter for setting the tap coefficients of the equalizer 37, and the equalizer 37 samples the baseband signal at the point when the eye is most open, and samples the baseband signal at a constant time interval T(1/ T herring porate).

In the coefficient setting device 36, as shown in FIG. The coefficient calculator 42 calculates the autocorrelation and cross-correlation of each signal using the reference signal from the correlator 40, and the coefficient calculator 42 generates a normal equation based on each correlation result calculated by the correlator 41, and the tap of the equalizer 37 is calculated based on the solution. A coefficient is set for each time interval T.

The equalizer 37 equalizes the baseband signal of the information data to which distortion has been added in the wireless transmission path using the tap coefficients set by the coefficient setter 36, and the decoder 38 equalizes the baseband signal of the information data that has been equalized by the equalizer 37. The information data is decoded from the received signal.

Therefore, according to the above conventional example, when a delayed wave occurs in the wireless transmission path, the tap coefficient of the equalizer 37 is adjusted at the time interval T.
By setting each time, distortion of the received signal can be compensated for, and transmission errors can therefore be reduced.

Problems to be Solved by the Invention However, in the conventional data transmission device described above, since the received signal is acquired at every time interval T and the equalizer 37 is operated, distortion caused by delayed waves can be removed, but There is a problem in that it is not possible to remove distortion caused by interference waves from

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide a data transmission device that can eliminate both distortion caused by delayed waves and distortion caused by interference waves from adjacent channels.

Means for Solving the Problems In order to achieve the above object, the present invention captures received signals at relatively long time intervals to determine tap coefficients of an isometric device,
This tap coefficient and the interpolation polynomial are used to determine the tap coefficients of the equalizer with a relatively short time interval, and the equalizer equalizes the received signal using the tap coefficients with this relatively short time interval. With the above-described configuration, the frequency range of the signal processed by the equalizer is expanded, so that both distortion caused by delayed waves and distortion caused by interference waves from adjacent channels can be removed.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the data transmission device according to the present invention, FIG. 2 is a block diagram showing the coefficient setter of FIG. 1, and FIG. 3 is the data transmission device of FIG. 1. FIG. 2 is an explanatory diagram showing a transmission signal of FIG.

In FIG. 1, 1 is a modulator that modulates digital data (baseband signal) of "0" and "1"; 2 is an amplifier that amplifies the signal modulated by the modulator 1 at high frequency;
Reference numeral 3 denotes an antenna for wirelessly transmitting the signal amplified by the amplifier 2, and the modulator 1, amplifier 2, and antenna 3 constitute a transmitting side.

As shown in Figure 3, the data sent from the transmitting side consists of a frame consisting of reference signal data and information data, and on the receiving side, the data for the black signal is already known. , the informational data is unknown.

4 is an antenna for receiving a radio signal from the transmitting side; 5 is an amplifier for high frequency amplifying the signal received via the antenna 4; 6 is a base for orthogonally detecting the high frequency signal amplified by the amplifier 5; This is a detector that converts into a band signal, and this baseband signal is a signal that has been distorted on a wireless transmission path.

7 is a coefficient setter for setting tap coefficients of the fractionally spaced equalizer 8, and the fractionally spaced equalizer 8 has a time interval T (1/T
The baseband signal is sampled at time points including the time point when the eye is most open, and is captured every time interval T/n (n: integer).

As shown in FIG. 2, the coefficient setter 7 includes a reference signal generator 21 that generates the same signal as the reference signal transmitted from the transmitting side, a signal from the detector 6, and a signal from the reference signal generator 21. A correlator 22 calculates the autocorrelation and cross-correlation of each signal using a reference signal, and a normal equation is generated from each correlation result calculated by the phase 71, . Based on the tap coefficients set by the coefficient calculator 23, the coefficients are calculated for each time interval T/n by the Nyquist interpolation method,
Interpolation coefficient calculation that corrects the coefficient sequence with time interval T/n and sets the tap coefficient of fractionally spaced equalizer 8 so that the power is equal to that of the equalizer of coefficient sequence with time interval T before interpolation. It is composed of a container 24.

A decoder 9 decodes information data from the signal equalized by the fractional interval equalizer 8.

Next, the operation of the above embodiment will be explained.

In FIG. 1, when a signal as shown in FIG. 3 is transmitted from the transmitting side (modulator 1, amplifier 2, transmitting antenna 3), the signal received at the receiving side is as follows.

O is a signal in which distortion due to delayed waves and distortion due to interference waves from adjacent channels are added in the wireless transmission path. The tap coefficient sequence of the fractional interval equalizer 8 is set at every interval T/n, and the fractional interval equalizer 8 takes in information data from the detector 6 at every time interval T/n, and the coefficient setter 7 Equalize using the set tap coefficient.

Therefore, according to the above embodiment, the fractionally spaced equalizer 8 having coefficients for each time interval T can be extended to an equalizer having coefficients for each time interval TZn. The frequency range of signals to be processed can be increased, and therefore distortion caused by interference waves from adjacent channels can be removed.

Furthermore, according to the above embodiment, after the coefficient setter 7 obtains the tap coefficients at a relatively long time interval T, the tap coefficients at a relatively short time interval T/n are determined by the interpolation polynomial. This method has the advantage that the amount of calculations is smaller than when calculating tap coefficients at short time intervals T/n.

As described in detail, the present invention obtains the tap coefficients of the equalizer by acquiring the received signal at relatively long time intervals, and uses the tap coefficients and the interpolation polynomial to obtain the equalizer tap coefficients at relatively short time intervals. Since we determined the tap coefficients of the equalizer and caused the equalizer to equalize the received signal by the tap coefficients of this relatively short time interval, the range of frequencies of the signal processed by the equalizer is expanded, and therefore , it is possible to remove both distortion caused by delayed waves and distortion caused by interference waves from adjacent channels.

[Brief explanation of the drawing]

1 is a block diagram showing an embodiment of the data transmission device according to the present invention, FIG. 2 is a block diagram showing the coefficient setter of FIG. 1, and FIG. 3 is the data transmission device of FIG. 1. FIG. 4 is a block diagram showing a conventional data transmission device, and FIG. 5 is a block diagram showing the coefficient setter of FIG. 4. 7... Coefficient setter, 8... Fractional interval equalizer, 21...
Reference signal generator, 22...correlator, 23...coefficient calculator, 24...interpolation coefficient calculator.

Claims (1)

[Claims] An equalizer that equalizes a signal received via a wireless transmission path using tap coefficients; a coefficient setter for determining tap coefficients of the equalizer at relatively short time intervals using coefficients and an interpolation polynomial; A data transmission device characterized by equalizing a received signal.