JPS58181337A - Signal detector - Google Patents

Abstract

PURPOSE:To detect the presence/absence of signals before the end of processing of addition and averaging, by extracting information such as partial adding and averaging values during the processing of addition and averaging. CONSTITUTION:A prestage adding and averaging device 5 subdivides the total number of adding and averaging processings of signals A/D-converted by an A/D converter 2 as basic units and performs addition and averaging at the number of times of the basic units. The output is distributed into plural storage devices by a distributor 7. An adding and averaging device 11 extracts a prestage adding and averaging value at each basic unit stored in the storage device 8 and performs addition and averaging further. An information extracting device 9 extracts the prestage adding and averaging value at each basic unit from the storage device 8 independently. Thus, the information relating to the reception state and the line state is obtained from this information and, for example, whether or not a signal is incoming in noise is obtained from the information on the way of the addition and averaging.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal detection device that performs signal detection using averaging processing.

Generally, when noise is superimposed on a signal that repeatedly changes in one period, averaging processing is used to suppress the noise component and detect the signal component. As shown in Figure 1, this averaging process synchronizes a periodically changing signal (a) with its period (b).
This is a signal processing method in which a sum signal (C) is obtained by sequentially adding signals in a time-series manner, and an added average value (d) is obtained by dividing by the number of additions. It is well known that when this averaging process is performed, the signal-to-noise ratio is improved in proportion to the square root of the number of times the averaging process is performed, compared to when the averaging process is not performed.

In a conventional signal detection device using averaging processing, averaging is performed sequentially as signals are input, with the number of averaging operations being sufficient to obtain a sufficient signal-to-noise ratio. Therefore, information such as intermediate addition average values could not be obtained during addition and averaging, and no information could be obtained until after all processing had been completed.

The present invention considers the shortcomings in conventional averaging processing, and
The purpose of the present invention is to provide a signal detection device that extracts information such as a partial average value during the averaging process and, based on this information, can detect the presence or absence of a signal, for example, before the averaging process ends. do.

The operating principle of the present invention will be explained using FIG. 2. As shown in FIG. 2(,), it is assumed that the number of times of addition and averaging to obtain a sufficient signal-to-noise ratio is N times, and these are transmitted as one group. This figure shows the repeated signal for N times (
The signal is subdivided as shown in b), and a unit containing a signal is defined as a basic unit.

This is called a frame. Each frame contains a repeated signal a number of times, and this frame is shown in the figure (
Suppose that n frames are possible as shown in C).

Here, the relationship among a, n, and H is N=a xn.

Further, as shown in FIG. 2(d), the average value is calculated for each frame by dividing it into frames.

In the present invention, the average value for each frame is calculated as shown in Figure 2 (,).
To remember or retain, respectively. The stored average value is used not only for the average processing but also as information for setting operating conditions of the transmitter/receiver. Further, the stored average value (e) for each frame is averaged again and signal decoding is performed.

As described above, according to the present invention, since information regarding the input signal state is obtained during averaging, it can be used to control operating conditions, etc., and effects such as more efficient signal decoding can be obtained. I can do it.

Next, an embodiment of the signal detection device of the present invention is shown in FIG.

1 is the input terminal, 2 is the analog-digital (hereinafter referred to as M/D)
It is a converter that converts an input signal into a digital quantity at a sampling period that does not lose the amount of information contained in the input signal. 3 is a signal period generator that generates a periodic signal corresponding to the repetition period of the input signal; 4 is a signal period generator 3;
This is a counter that counts the number of data for one frame from the periodic signal that is the output of. In the above, the signal period is set in advance on the transmitting side and the receiving side. This is because when detecting a signal from a state where the signal is buried in noise, it is extremely difficult to directly obtain the signal period from the input signal. Reference numeral 6 denotes a pre-adding and averaging device that adds the digital signals from the FM/D converter. A device 6 adds and averages. The control device 6
Further, when the set number of times is reached, the counter 4 is reset and the count is reset, the output of the pre-adding and averaging device 6 is distributed to the storage device 8 having a plurality of storage locations by the next distributor 7, and The pre-adding and averaging device 6 is reset by this control device 6. The distributor 7 distributes the frames so that they can be stored in locations corresponding to the frame numbers in the storage device 8.

After the distribution, the control device 6 starts averaging for the next frame. Since the arithmetic average value for each frame is stored in the storage device 8 at a location corresponding to each frame number, the information extraction device 9 extracts the necessary information from these and outputs the control signal from the control output terminal 1o. Output. On the other hand 1
Reference numeral 1 denotes an averaging device which averages the output of the storage device 8 again, and based on this addition result, a signal decoding device 12 decodes the signal, and outputs the decoding result from an output terminal 13.

In the configuration of the above embodiment, the pre-adding and averaging device 6 performs the averaging process for each frame and stores this in each frame Vc in the storage device 8 corresponding to each frame. This means that information in the middle of addition and averaging is stored. From this information, information regarding the reception status and line status can be obtained.1 For example, information about whether or not a signal is arriving during noise is obtained during this addition and averaging (output of the storage device 8).
can be obtained from. Therefore, only when the information extraction device 9 detects the arrival of the above-mentioned signal, it sends to the output terminal 10 a control signal for operating other parts of the receiving device, a control signal for driving a display device that displays reception, etc. generate. Also, fading may occur during reception.
This storage device 8 can also be used when there are other fluctuations in reception strength.
The information extraction device 9 can detect the output from the signal and generate a signal that automatically controls the gain and reception frequency. In other words, the information extraction device 9 is
Instead of waiting for the averaging process to be completed a sufficient number of times to completely determine the contents of the signal as in the past, the necessary information regarding the reception status and line status can be obtained at an early stage, allowing the receiving device to etc. can be quickly brought to a predetermined state. Therefore, it is possible to shorten the time required to start receiving operation, and to perform communication with high efficiency and fewer errors.

Further, in the above embodiment, the counter 4 is controlled by the control device 6 so that an equal number of pre-additions is performed so that each frame contains signals for a number of addition averages, as shown in FIG. 2(C). The averaging device was set to 6. As shown in Fig. 4(b), the number of signals included in each frame can be arbitrarily set, and the information that is particularly desired to be extracted can be selected.Here, the total number of data for n frames is N. (1) If you want to change the number according to the signal-to-noise ratio, if you calculate the signal-to-noise ratio from the first frame evenly divided,
It takes a lot of time to process. 4. For example, if the first frame has six times as much data (that is, 50 times), and each subsequent frame has a number of data, it is possible to reduce the time required for processing.

As described above, according to the present invention, the total number of addition averages is subdivided into basic units, and the pre-addition average value obtained by performing addition averaging for each basic unit is stored in the storage device. The pre-added average value for each basic unit is retrieved from the storage device and averaged, and the information contained in the retrieved pre-added average value is obtained by the extractor, so all the average processing is performed. Before the end of the process, it is possible to obtain information such as the presence or absence of an incoming signal, the strength of the signal, etc. by using the pre-added average value, and it is possible to form signals to control other devices in advance, so that the reception of the signal can be improved. Accordingly, it is possible to provide an excellent signal detection device that reduces waiting time, improves processing efficiency, and can prepare for reception more quickly, thereby reducing errors and the like.

[Brief explanation of drawings]

Figures 1 (-) to (d) are waveform diagrams for explaining averaging processing by a conventional signal detection device, and Figures 2 (,) to (e
) is a waveform diagram for explaining the operation in one embodiment of the present invention. 1... Input end, 2... Mu/D converter,
3...Signal period generator, 4...Counter, 6...Pre-addition and averaging device, 6...
・Control device, 7...Distributor, 8('Z1...
...Storage device, 9...Information extraction device, 1o.
...Output end, 11...Additional averaging device, 1
2...Signal decoding r6+ device. Name of agent: Patent attorney Toshio Nakao (1 person)
C) /d) Figure 1

Claims (1)

[Claims] (1) A pre-adding and averaging device that subdivides the total number of additions and averaging into basic units and performs addition and averaging for each number of basic units, a storage device that stores the output of this pre-addition and averaging device, and this storage device. an averaging device for extracting and further averaging the pre-added average value for each basic unit stored in the storage device; What is claimed is: 1. A signal detection device comprising: an extraction device for obtaining the information contained in the signal. (b) The signal detection device according to claim 1, wherein the number of data included in each basic unit can be arbitrarily set as necessary.