JPH02203625A - Transmission power control method - Google Patents

Abstract

PURPOSE:To compensate the deterioration in the line quality by extracting an error signal corresponding to an error of a reproduced data from an identification means in a reception and demodulation section. CONSTITUTION:The title method is provided with an identification means 53 setting an identification level and a line quality decision identification level in a prescribed range including the identification level in advance, converting a base band signal inputted into a relevant data by using the identification level, and sending an error signal the number of times when the base band signal enters the relevant range reaches a setting value or over within a time T at the point of time of identification and a transmission power control means 4 sending relevant transmission power control information corresponding to the state of an error signal outputted from the identification means. Then the receiver side is provided with the identification means 53 and a transmission power control decision means 6 and the transmission power control information is sent to the transmission power control means 4 at the sender side so as to eliminate the sent error signal. Then an attenuation control signal corresponding to the transmission power control means 4 controls the attenuation of the variation attenuator to control the transmission power. Thus, the deterioration in the line quality is compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] This invention relates to a transmission power control method used in a digital multiplex radio device.

The purpose of this invention is to perform transmission power control that can compensate for deterioration in line quality, and to provide a transmission power control means for transmitting an attenuation control signal in accordance with the state of input transmission power control information, and the attenuation control signal. a transmitting side having a transmitting section that controls the amount of attenuation of the variable attenuator and transmitting the corresponding transmission power; and a receiving side that has a receiving/demodulating section that demodulates the received signal and extracts data from the obtained baseband signal. In a digital multiplex radio system that communicates with a receiving side, an identification level and a predetermined line quality determination identification level including the identification level are set in advance on the receiving side, and the input baseband signal is determined using the identification level. Along with converting to the corresponding data! ! identification means for transmitting an error signal when the number of times the baseband signal falls within the predetermined range within one hour at a different point in time; A transmitting power control means for transmitting the transmitting power control information is provided, and the transmitting power is controlled so that no error signal is transmitted.

[Industrial application field]

The present invention relates to a transmission power control method used in digital multiplex radio equipment.

When transmitting the main signal to the receiving side using a digital multiplexing radio device, for example, when the receiving level on the receiving side drops, the transmission power of the digital multiplexing radio device is increased so that the receiving level falls within a predetermined range. Sometimes. At this time, it is necessary to perform transmission power control that can compensate for deterioration in line quality.

[Conventional technology]

FIG. 5 shows a block diagram of a conventional example. In the following, it is assumed that data is transmitted using the 16-value orthogonal amplitude modulation method.

The operation of the diagram will be explained.

First, the modulator 11 generates a 16-level orthogonal amplitude modulated wave (hereinafter 116Ω^ will be abbreviated as wave) in the intermediate frequency band using the input four series of data, and applies it to the transmitter 12 .

In the transmitting section, the 16QAM wave in the intermediate frequency band is converted to frequency converter 1.
After converting to a predetermined transmission frequency at 21, the variable attenuator 12
2. The signal is transmitted to the receiving side via the transmission power amplifier 123 with a predetermined power.

On the receiving side, the receiving section 21 converts the signal into a 16QAM wave in the intermediate frequency band, and then amplifies it to a predetermined level using an automatic gain control amplifier (hereinafter referred to as an AGC amplifier, not shown) and applies it to the demodulating section 22. In the demodulation section, the orthogonal detector 221 detects Ic
The h baseband signal and the Qch baseband signal are extracted, identified by the corresponding discriminators 222, and the data is reproduced (the figure shows only Ich data). Here, the reception level output from the AGC amplifier (AG
(The level of the gain control signal of the C amplifier corresponds to the reception level) is added to the transmission power control judgment circuit 31, so this judgment circuit 31 monitors whether the reception level is above or below the specified value, and if it is below the specified value. When the transmit power control information becomes
C insertion circuit 32. Reverse control line, DSC extraction circuit 4
2 to the transmission power controller 41. Note that OSC is an abbreviation for Digital 5service Channel, and is a channel for transmitting meeting signals and monitoring/control signals.

Transmission power controller 41 detects transmission power control information.

An attenuation control signal corresponding to this information is sent out to reduce the attenuation of the variable attenuator 122 and increase transmission power. As a result, the reception level becomes equal to or higher than the specified value.

(Problems to be Solved by the Invention) The above transmission power control is based on the premise that if the reception level decreases, the line quality will also decrease accordingly. However, although such a premise holds true when the receiving side receives only the desired wave, it does not hold when the receiving side receives the desired wave and the interference wave at the same time.

For example, the reception level of the desired wave is 120 dBm T:C/
If N is 60 dB and an interference wave is input at 150 dBI11, the C/N becomes 30 d[l, which degrades the quality of one line. However, since the reception level hardly changes at -20 dBII+, no transmission power control is performed. That is, there is a problem in that the transmission power is not high enough to compensate for deterioration in line quality.

An object of the present invention is to perform transmission power control that can compensate for deterioration in line quality.

[Means to solve problems]

FIG. 1 shows a block diagram of the principle of the present invention.

In the figure, reference numeral 53 presets an identification level and a line quality determination identification level in a predetermined range including the identification level, converts the input base band signal into corresponding data using the identification level, and converts the input base band signal into corresponding data, and Identification means transmits an error signal when the number of times the band signal falls within the predetermined range is equal to or greater than a set value within T time, and 6 indicates the transmission power according to the state of the error signal output from the identification means. This is a transmission power control means that sends out control information.

Then, an identification means 53 and a transmission power control determination means 6 are provided on the receiving side, and transmission power control information is sent to the transmission power control means 4 on the transmitting side so that no error signal is sent out.

Therefore, the attenuation of the variable attenuator is controlled by a corresponding attenuation control signal from the transmission power control means 4, thereby controlling the transmission power.

[Effect]

In the present invention, an error signal corresponding to an error in reproduced data is extracted not from the reception level but from the identification means in the reception/demodulation section.

That is, FIG. 2(a) shows the eye pattern of the baseband signal input to the identification means 53 when the line quality is not degraded.
D is a discrimination point for identifying whether the position of the signal point is 1 or 0,
D4 is an identification point for determining line quality. When the line quality does not deteriorate, the signal point is located outside D4. However, when the line quality deteriorates, the opening of the eye pattern becomes narrower and the position of the signal point becomes D4, as shown in Figure 2 (c).
The probability that it will be inside + Dl will be higher.

Therefore, the number of times it has entered the inside is counted, and when this number exceeds a specified value within time T, an error signal is sent to the transmission power control determining means. The transmission power control determining means sends out transmission power control information corresponding to the state of the error signal, and increases the transmission power by a predetermined value.

However, if the error signal becomes less than a predetermined value within time T, the transmission power is reduced by a predetermined value.

In this way, since the transmission power is controlled using the error signal that directly indicates the line quality, the transmission power can be controlled to compensate for the deterioration of the line quality.

〔Example〕

FIG. 3 is a block diagram of an embodiment of the present invention, FIG. 4 is a diagram explaining the operation of FIG. 3, and FIG. 4(a) is a diagram 2 explaining the operation of the discriminator.
FIG. 4(b) shows an explanatory diagram of transmission power control.

Here, the transmission power controller 41. The DSC extraction circuit 42 is a component of the transmission power control means 4, and the receiving section 51. Quadrature detector 52. Discriminator s3': Bx-on game 1-54.
The OR gate 55 and the counter 56 are components of the receiving/demodulating section 5, the transmission power control judgment circuit 6L, and the DSC insertion circuit 62.
1 shows the constituent parts of the transmission power control means 6.

Note that the same reference numerals indicate the same objects throughout the figures.

Hereinafter, the operation in FIG. 3 will be explained with reference to FIG. 4 assuming that T=t.

First, the modulator 11 generates 16 CAM waves using input data, the frequency is converted by the frequency converter 121 in the transmitter, and the variable attenuator 122... It is transmitted to the receiving side via the amplifier 123 with a predetermined transmission power and one frequency.

On the receiving side, a receiving section 51 frequency-converts the received 16QAM wave into a 160 static wave in an intermediate frequency band, and sends it to a quadrature detector 52 at a predetermined level. The quadrature detector has 4 Ich and Qch
Since the baseband signal of each value is extracted and added to the corresponding discriminator (the Qch discriminator is not shown), the discriminator is divided into one signal point corresponding to the position of the signal point as shown in Fig. 4(a).
For example, 4-bit identification data is sent. Of these, the first and second bits identified by identification points D and D are output data, and the third bit identified by identification points D3+D4.

The fourth bit becomes an error signal.

Here, when the exclusive OR (hereinafter abbreviated as EX-OR) of the third and fourth bits is taken by the EX-OR gate 54, the position of the signal point is determined as shown in FIG. 4(a). If it does not fall within the shaded area, 1. If it enters the shaded area, it becomes 0, but 0
As mentioned above, the state indicates that the line quality has deteriorated and the opening of the eye pattern has collapsed, and there is a high probability that an error will occur in the reproduced data.

Therefore, the error signal is added to the counter 56, and the counter counts how many times the error signal is input within 11 hours.

When the number of times exceeds the predetermined number, an error signal is sent to the transmission power control determination circuit 61 via the OR gate 55.

When the transmission power control determination circuit 61 receives an error signal, it converts the transmission side power control information into DSC as shown in FIG. 4(b)-0.
Since the signal is sent to the transmission power controller 41 on the transmitting side via the insertion circuit and the DSC extraction circuit, the attenuation amount control signal is sent from this controller to adjust the attenuation amount to a predetermined amount as shown in FIG. 4(b)-■. only decrease and increase the transmit power.

If the error signal is input again, the same operation as above is performed to further increase the transmission power. but.

If no error signal is input within time t1, the transmission power is reduced by a predetermined amount, and if no error signal is input within time t, the original transmission power is restored.

As a result, transmission power control that can compensate for deterioration in line quality is performed.

In the figure, 4 is a transmission power control means; 5 is a receiving/demodulating section; 6 is a transmission power control determination means; 53 indicates identification means.

〔Effect of the invention〕

As described above in detail, the present invention has the effect of performing transmission power control that can compensate for deterioration in the quality of one line.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is an explanatory diagram of the operation of Fig. 1, Fig. 3 is a block diagram of an embodiment of the present invention, Fig. 4 is an explanatory diagram of the operation of Fig. 3, and Fig. 5 The figure shows a block diagram of a conventional example. Mun L 41ζ A standard bow I $ I four failure g month /) Slide, de fig. Takukatsucho Σ 4th concave

Claims (1)

[Claims] Transmission power control means (4) that sends an attenuation control signal in accordance with the state of input transmission power control information, and controlling the attenuation of a variable attenuator (122) using the attenuation control signal. a transmitting side having a transmitting section (12) which sends out the corresponding transmission power; and a receiving side having a receiving/demodulating section (5) which extracts data from the baseband signal obtained by demodulating the received signal. In a digital multiplex wireless system that performs communication, an identification level and a predetermined range of line quality determination identification levels including the identification level are set in advance on the receiving side, and the identification level is used to convert input baseband signals to corresponding data. an identification means (53) for converting the baseband signal into the predetermined range and transmitting an error signal when the number of times the baseband signal falls within the predetermined range at the time of identification is equal to or greater than a set value within time T; and an error signal output from the identification means. A transmission power control method, comprising: a transmission power control means (6) for transmitting the transmission power control information in accordance with a signal state, and controlling transmission power so that no error signal is transmitted.