JPH0832528A - Reception eb/no detection circuit - Google Patents

Abstract

PURPOSE:To properly monitor deterioration in data quality in a remote sensing data communication channel and an inter-satellite communication channel or the like utilizing a non-carrier signal through PCM direct modulation. CONSTITUTION:In addition to detection of a reception level and a noise level in a reception level detection section 1 and a noise level detection section 2, a bit rate is measured by inputting a recovered clock signal recovered by a receiver to a counter section 13 and Eb/No is calculated based on a reception level, a noise level, a bit rate in an arithmetic section 12 and correction data in a memory section 14. Thus, the quality of the reception signal is monitored without the detection of the bit error rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reception Eb / No detection circuit, and more particularly, to a reception Eb / No detection circuit for reducing data quality deterioration in a remote sensing data communication line using a carrier-less signal by PCM direct modulation, an inter-satellite communication line and the like. The present invention relates to an apparatus for monitoring by measurement.

[0002]

2. Description of the Related Art A conventional circuit for detecting a reception quality or a reception state includes a reception level detection circuit for extracting a voltage of a signal component, a noise level detection circuit for extracting a noise component, and an S It is composed of a judgment circuit for judging the quality of / N, and the reception quality or the reception state is judged mainly by performing S / N detection.

[0003]

In the phase modulation system based on PCM direct modulation, reception quality is indicated by a ratio of signal energy per bit to noise power density per unit frequency, and it is difficult to evaluate quality only by S / N detection. Met.

Also, by using data such as a PN code and knowing the transmission data in advance, it is possible to measure the data from the demodulated data with a bit error measuring device or the like. It is difficult, and the measurement and evaluation are further complicated by coding and the like, so that evaluation by bit error measurement is difficult.

An object of the present invention is to provide a reception Eb / No detection circuit for properly monitoring data quality deterioration in a remote sensing data communication line, an intersatellite communication line, etc. using a carrierless signal by PCM direct modulation. is there.

[0006]

The reception Eb / No of the present invention is described.
The detection circuit includes a reception level detection unit that detects a reception signal level, a noise level detection unit that detects a noise signal level, an A / D conversion unit that digitally converts the detection results of the reception level detection unit and the noise level detection unit. , A counter unit that counts a reproduced clock reproduced in a receiver to measure a bit rate, a memory unit that stores condition data for calculation and correction, a digitally converted reception level and noise level, and a bit rate And an arithmetic unit that calculates Eb / No using the correction data stored in the memory unit.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

The received signal input is connected to the bandpass filter 3, and the output of the bandpass filter 3 is connected to the AGC amplifier 4. The output of the AGC amplifier 4 is the envelope detector 5 and
It is connected to a carrier recovery unit and a clock recovery unit (not shown). The output of the envelope detector 5 is the loop filter 6
The output of the loop filter 6 is connected to the AGC amplifier 4 and the A / D converter 11.

The received signal input is connected to the bandpass filter 7, and the output of the bandpass filter 7 is connected to the AGC amplifier 8. The output of the AGC amplifier 8 is the envelope detector 9
, The output of the envelope detector 9 is connected to the loop filter 10, and the output of the loop filter 10 is AGC.
It is connected to the amplifier 8 and the A / D converter 11.

Further, an output of a clock reproducing unit (not shown) is connected to a counter unit 13, and the counter unit 13, A / A
The D conversion unit 11 and the memory unit 14 are the calculation unit 1
Connected to 2.

The AGC amplifier 4, envelope detector 5 and loop filter 6 constitute an AGC circuit, and the AGC circuit and bandpass filter 3 constitute a reception level detector 1. The AGC amplifier 8, the envelope detector 9, and the loop filter 10 constitute an AGC circuit, and the AGC circuit and the bandpass filter 7 constitute a noise level detection unit 2.

Next, the operation of this embodiment will be described.

The input received signal is distributed to each of a reception level detection unit 1 and a noise level detection unit 2. In the reception level detector 1, the bandpass filter 3 improves the S / N of the input signal, and the AGC circuit including the AGC amplifier 4, the envelope detector 5, and the loop filter 6 controls the reception level. A considerable AGC voltage is obtained. AGC voltage is LOG in order to improve calculation accuracy.
-Perform LINEAR conversion.

In the noise level detector 2, the bandpass filter 7 extracts only the thermal noise near the signal, and the AGC circuit composed of the AGC amplifier 8, the envelope detector 9 and the loop filter 10 extracts the noise. Get the voltage according to the level. FIG. 2 is a diagram showing the frequency relationship of the bandpass filters 3 and 7.

The A / D converter 11 includes a reception level detector 1
Then, the detection voltage output from the noise level detection unit 2 is converted into a digital value and sent to the calculation unit 12.

The counter unit 13 measures the bit rate by inputting a reproduction clock reproduced in the receiver main body, and sends the result to the calculation unit 12.

In the operation unit 12, the A / D conversion unit 1
1. Using the data of the counter unit 13 and the calculated correction data stored in the memory unit 14, C / No, Eb / N
o is calculated and the result is output to the outside.

[0018]

As described above, according to the present invention, Eb / No can be detected by adding a bit rate detection function, and the data quality of a received signal can be monitored without detecting a bit error rate. It has the effect of being able to do it. In particular, it is effective for a bit rate tunable receiver.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a frequency relationship of the bandpass filter shown in FIG.

[Explanation of symbols]

 1 Reception level detection unit 2 Noise level detection unit 3,7 Bandpass filter 4,8 AGC amplifier 5,9 Envelope detector 6,10 Loop filter 11 A / D conversion unit 12 Operation unit 13 Counter unit 14 Memory unit

Claims (3)

[Claims] 1. A reception level detection section for detecting a reception signal level, a noise level detection section for detecting a noise signal level, an A / D conversion section for digitally converting a detection result of the reception level detection section and the noise level detection section. A counter section that counts a reproduced clock reproduced in the receiver to measure a bit rate, a memory section that stores condition data for calculation and correction, a digitally converted reception level and noise level,
A reception Eb / No detection circuit having a bit rate and a calculation unit that calculates Eb / No using correction data stored in a memory unit. 2. The reception level detecting section comprises a bandpass filter for extracting a reception signal and an AGC circuit for obtaining a voltage according to the extracted reception signal level, and the noise level detecting section is provided near the reception signal. 2. The receiving Eb according to claim 1, comprising a bandpass filter for extracting only the thermal noise of the above and an AGC circuit for obtaining a voltage according to the noise level.
/ No detection circuit. 3. The reception Eb / No according to claim 1, wherein the reception Eb / No is used for an apparatus for monitoring data quality deterioration of a remote sensing data communication line and an inter-satellite communication line using a carrier-free signal by PCM direct modulation. Detection circuit.