JPS62171337A - Receiver for time division multiple access communication - Google Patents

Abstract

PURPOSE:To utilize a signal for burst mode link analyzer (BMLA) measurement without placing a phase demodulator in abnormal operation by making a selection by a hopping switch and inhibiting a signal which is not addressed to a station from being inputted to the terminal device of the station, and extracting the signal separately. CONSTITUTION:Plural carriers from a satellite are received by an antenna 1. The output of the antenna 1 is connected to the input of a low-noise amplifier 2 and amplified. The output of the amplifier 2 is connected to the input of a distributor 3. The output of the distributor 3 is distributed and connected to N reception systems, i.e. frequency converters 41-4N. The signal is converted to a center frequency by each frequency converter and the outputs of the respective frequency converters 41-4N are connected to respective inputs of the hopping switch 5. The hopping switch 5 selects the outputs of the respective frequency converters and a signal addresses to the station is connected to the input of its terminal device 7 through an output terminal 6. Further, other signals such as a signal for BMLA measurement are connected to an output terminal 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a time division multiple access communication receiving apparatus suitable for satellite communication.

[1 Already Required] The present invention provides a time-division multiple access communication receiving device for satellite communication, in which a hopping switch selects a signal destined for a station other than one's own station.
By prohibiting input to the station terminal equipment and extracting this signal separately, it is possible to use the measurement signal for BMI without causing the phase demodulator to malfunction.

[Conventional technology]

Conventionally, in a time division multiple access communication receiving apparatus using a satellite, a frequency hopping method has been used in which a plurality of carrier waves are shared in order to provide line efficiency and flexibility of the apparatus. That is, it is necessary to send a time division multiple access signal to an appropriate carrier wave at an appropriate time, and to extract only an appropriate signal (burst signal) at an appropriate time from among a plurality of received carrier waves. This requires an N-to-1 switch that selects only one of N types of carrier waves. This N to 1
The switch was called a hopping switch and was switched in synchronization with the time division multiple access signal to extract the signal destined for the local station and send the signal to the demodulator.

[Problem that the invention seeks to solve]

However, in such a time division multiple access communication receiving device,
In recent years, burst mode link analyzers (hereinafter referred to as BMLA)
That's what it means. ), a device was developed that measures the amplitude and delay characteristics of satellites and earth stations by using the time when burst signals of time division multiple access communications are not being transmitted.

Unlike the signals used for communication, this BML^ measurement signal has a frequency far from the center frequency, so the carrier regeneration circuit of the phase demodulator cannot follow it, resulting in abnormal operation of the phase demodulator. . This is because the conventional hopping switch selects the necessary one wave out of the N carrier waves, and after selecting it, sends all the signals to the phase demodulator.
This is because the MLA measurement signal may also be sent to the phase demodulator, causing the phase demodulator to malfunction.

The present invention solves the above-mentioned drawbacks, and aims to provide a time division multiple access communication receiving apparatus that can utilize a BMLA measurement signal without causing abnormal operation of the phase demodulator.

[Means for solving problems]

The present invention provides a time division multiple access system having a hopping switch that sequentially selects one of a plurality of receiving systems and supplies a signal addressed to the own station from a first output terminal (6) to a terminal device. In the communication receiving device, the hopping switch includes a prohibiting means for prohibiting signals other than a burst signal addressed to the own station among the signals of the selected receiving system from being sent to the first output terminal; It is characterized by comprising a second output terminal (8) that sends out a signal other than the burst signal addressed to the own station.

[Effect]

Since the BMLA measurement signal is not sent to the first output terminal, abnormal operation of the phase demodulator can be prevented.

On the other hand, the BMLA measurement signal can be identified and used from the second output terminal.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of a time division multiple access communication receiving apparatus according to an embodiment of the present invention. In FIG. 1, a plurality of carrier waves are received by an antenna 1 from a satellite not shown. The output of antenna l is connected to the input of low noise amplifier 2 and amplified. The output of amplifier 2 is connected to the input of divider 3. Distributor 3
The output of N receiving systems, that is, frequency converters 4I to 4
H and are respectively distributed and connected.

Here, the feature of the present invention is the signal selection portion addressed to the local station surrounded by the dashed line. That is, each frequency converter converts to the center frequency, and each frequency converter 4. ~4N
The outputs of are connected to respective inputs of the hopping switch 5. The hopping switch 5 selects the output terminal of each frequency converter, and the signal addressed to the own station is connected to the input of the terminal device 7 via the output terminal 6. Further, a signal not addressed to the own station, for example, a BMLA measurement signal, is connected to the output terminal 8.

The operation of the time division multiple access communication receiving apparatus having such a configuration will be explained. FIG. 2 is a time chart of signals of each part of the time division multiple access communication receiving apparatus of the present invention.

In FIG. 1, a signal received by an antenna 1 is divided into N by a distributor 3, and the divided signals are transmitted through frequency converters 41 to
After being converted into an intermediate frequency by 4N, the signal is supplied to the hopping switch 5. Among the signals supplied to the hopping switch 5, for example, the frequency converter 4. (Although not shown, the i-th frequency converter among the frequency converters 41 to 4N is assumed to be frequency converter 4.) A signal shown at +81 in FIG. 2 is outputted. The signal addressed to the own station is shaded, but in order to output this signal from the hopping switch 5, conventionally the gate signal GI shown in FIG. The signal shown in C) was output to the terminal device 7. However, the burst i is originally an unnecessary signal to the own station, and if it is a signal for B) ILA measurement, it is output to the terminal device 7. The phase modulator operates abnormally. For this purpose, in this embodiment, the gate signals G2, G, applied to the hopping switch 5 are
Two types of gate signals shown in Figure 2 (dl) are prepared.
2 to the terminal 6 and the gate signal G3 shown in FIG. 2(e) to the terminal 8, the bursts i1 and i4 shown in FIG. A burst i shown in FIG. 2 (gl) is output to the terminal station 7. Therefore, only the signal addressed to the terminal station 7 is output, and the phase demodulator does not operate abnormally.

〔Effect of the invention〕

As explained above, in the present invention, a hopping switch is provided with two output terminals, the first output terminal outputs a burst signal destined for the own station, and the second output terminal outputs a burst signal destined for the own station. This output has the excellent effect of preventing the phase demodulator in the terminal equipment from operating abnormally. Furthermore, it is possible to obtain a BMLA measurement signal from the second output terminal and measure the amplitude characteristics and delay characteristics of the satellite line.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a time division multiple access communication receiving apparatus according to an embodiment of the present invention. FIG. 2 is a time chart of signals of each part of the time division multiple access communication receiving apparatus of the present invention. l...Antenna, 2...Amplifier, 3...Distributor,
4I to 4N... Frequency converter, 5... Hopping switch, 6.8... Output terminal, 7... Terminal device, 8
...Gate signal, t, -1, ...Burst signal. Patent Applicant: NEC Corporation - Agent: Patent Attorney Nao Takashi IdeExample Child 1 Figure Example Time Chart

Claims (1)

[Claims] (1) Time division multiple access communication reception equipped with a hopping switch that sequentially selects one of a plurality of receiving systems and supplies a signal addressed to the local station from the first output terminal (6) to the end station device. In the apparatus, the hopping switch includes a prohibition means for prohibiting signals other than a burst signal addressed to the own station among the signals of the selected receiving system from being sent to the first output terminal; a second output terminal (8) for transmitting a signal other than the addressed burst signal.