JPH0239633A - Transmission power controller for satellite communication device - Google Patents

Abstract

PURPOSE:To make a C/N detecting part unnecessary by measuring the C/N by the square output of the correlation value of a digital matched filter. CONSTITUTION:A signal asynchronously dropped into a base band with a mixer 2, a hydrid 9, and an oscillator 10 is firmly decided by an A/D converter 4 and inputted to a 90 deg. phase shifter 11. The correlation value between the input signal and a diffusion code is obtained by obtaining the coincident number between the value of the 90 deg. phase shifter 11 and the value of a shift register 12 and squaring and adding the outputs of both channels, and the diffusion code is caught using this correlation value. Next, a comparing diffusion code to obtain the correlation between the input signal and itself is changed into the diffusion code to be transmitted by its own station, the C/N of the input signal is obtained by the output of the digital matched filter at that time, rainfall attenuation quantity is estimated from the C/N, and transmission power is controlled. Thus, the C/N detecting part becomes unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission power control device for a satellite communication device.

[Conventional technology]

FIG. 2 is a block diagram of a conventional satellite communication transmission power control device using glue. In the figure, (1) is a P that extracts the frequency of the PILOT signal that has been converted into an IF.
LL, (2) is a mixer that multiplies the extracted signal and PILOT signal, (3) is an LPF that removes high frequency components from the output of mixer (2), and (4) is a digital filter that converts the output of LPF (31). N converter to convert to value, (5) 4 to conversion (7)?: Me (7) CLOCK, (6) is CLOCK
A processor that calculates to 9 based on the output of (5), (7
) is a transmission power control section.

I will explain the operation shortly. By multiplying the signal component of the PILOT signal extracted by P L L (11) and the input PILOT signal by a mixer (2) and passing it through an LPF (3), a voltage with noise added to the signal level is obtained. In other words, the input PILOT signal is
1-ns (sinwct-nc(t)coswct, electric kioJct) -nc(t)siBωct
becomes. If high frequency components are removed from this n by L P F (3) (and the output of the low-pass filter (3) is σ2, then
q乍= 1011og A2/ 2σ! (dB). ~0 converter (4) converts the output of the low-pass filter (3) directly into digital f, and Brossette converts it to 10! By calculating #gAn2-, 9 儒 is obtained. Rain attenuation is estimated from the variation of this C/N value, and the transmission power of the satellite communication equipment is controlled.

The problem that Inmei is trying to solve] Since the transmission power control device of the conventional 9-core Eiji communication device was configured as described above, we specially designed C/N@
Since the lii section is required, there are problems such as making the device larger and more expensive.

This invention was made in order to solve the above-mentioned problems, and its purpose is to easily estimate the φ detection unit and control the transmission power of the communication device without the need for a special φ detection unit. shall be.

[Means for Solving the Problems] A transmission power control device for a WI star communication device according to the present invention 1 is provided with a transmission power control device for a WI star communication device according to the present invention, in which when a spreading code is captured by an i-tched filter in a receiving section of a spread spectrum communication method, when the spreading code capturing is completed, the input Change the comparison spreading code that correlates with the signal to the spreading code transmitted by the own station, and calculate the C/N of the received signal by the output of the digital matched filter at that time.
The amount of rain attenuation is estimated from this and the transmission power is controlled.

[For production]

In estimating the fragility in the present invention, the nine folds of the received signal are obtained from the output of the digital matched filter, the amount of rain attenuation is estimated from this, and the transmission power is controlled.

〔Example〕

Mixer for baseband, (4) is 1 bi
The addition section (7) is a section that controls the transmission power. αη is a code generation section.

Next, the operation will be explained. The signal asynchronously converted to the baseband by the 2 x (2), hybrid (9) 0 oscillator αG is used by the ~4 converter (4) to find the number of matches between the value of the hard disk and the value of shift register 4, By squaring and adding the outputs of both channels, a correlation value between the input signal and the spreading code is obtained.

The spreading code is captured using this correlation value.

When the acquisition of the spreading code is completed, the correlation value will be maximum if the spreading code to be compared is the transmission code of the local station is acquired, but this value will vary depending on the value. When the number of stages in which correlation is taken is infinite, the square of the correlation value is N8.

The relationship between the maximum value of the correlation value and the maximum value of the correlation value is 1L-N (1-2Pe(9乍)) R: Correlation value, P e(x) s Error when C7'N is X Therefore, if the R station S is known, the C/N can be found. The amount of rain attenuation is estimated based on this value and the transmission power is controlled.

In the above embodiments, a digital matched filter is used as the spreading code capture circuit, but an integral-discharge filter may also be used. FIG. 2 shows another embodiment of the present invention, in which (1) the input IF multiplied signal αη is used in a spreading code generator to generate a spreading code that is the same as that of the input signal. (2) is input! F scratch signal 1
) is a mixer that multiplies and combines the code generator αη, α is a band pass filter that limits the band of the signal after despreading, (
2) is a square circuit.

α■ is an integral-radiator [The output after the code is captured by the filter changes depending on the signal level. From the fluctuations in this level, the input signal is calculated, and the amount of rainfall attenuation is estimated.
Control transmit power.

〔Effect of the invention〕

As described above, according to the present invention, since the 9-value measurement is performed using the squared output of the correlation value of the digital matched filter, a special q11 multiplex section is not required, so the device can be easily constructed, and This has the effect of making it smaller.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a satellite communication transmission control method according to one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the invention, and FIG. 3 is a block diagram showing a conventional method. . (1) is PLL, (21 is mixer, (3) is low-pass filter, (4) is A/D converter, (51 is CL
OCK, [61 is a processor, (7) is a transmission power control unit, (8) is a human-powered IF multiplier signal (9) is a no-brid,
I am an oscillator, (2) is a 90 phase shifter, (2). The 0th floor is a shift register, the α slope is a match bit number adder, (
) is a square circuit, 0 is an adder, and αη is a code generator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Comparison of a digital matched filter of a satellite communication device using spectrum and spreading and this digital matched filter; Means for switching a spread code to a local station transmission spread code after completion of capturing the spread code of an input signal; and a digital matched filter for local station transmission A means for estimating the C/N of an input signal from a correlation output with a spreading code, a means for converting rain attenuation of a map link from fluctuations in this C/N, and a means for controlling transmission power to compensate for this. A transmission power control device for a satellite communication device, comprising: