SU403083A1 - METHOD OF TRANSMISSION-RECEPTION OF RADIOTELEPHONE SIGNALS WITH TEMPORARY DIFFERENCE - Google Patents

Description

one

The invention relates to the field of signal transmission.

Methods are known for the non-transmitting reception of radiotelephone signals with the time separation of the individual central components of the power lines and their inverse transformation in reception.

However, the known methods do not provide for the reduction of the mutual loot of radio stations located on the same object.

The proposed method differs from the known one in that it delays each time sample by a time equal to the duration of the sample, multiplied by its order number, transforms each sample but at a frequency such that the spectra of each sample overlap, emit all samples simultaneously, and receive signals from other radio stations are produced in the pauses between the radiation, which significantly reduces mutual interference.

FIG. 1 shows a block diagram of a transmitter and a receiver implementing the proposed method; in fig. 2 - graphics, but removing the operation of the transmitter.

The essence of the method is that the transmitted speech signal of each radio station at a certain time interval T is divided into K segments of the same duration t, then it is reconstructed in frequency so that each frequency subchannel contains the same information relative to the previous subchannel, carry out a temporal selection of the converted signal

and emit the information accumulated over time T over time t, and only the time interval T-t in each pulse period is used to receive signals from all the radio stations of the object.

-All radio stations located in one object operate as pulses of duration t with a period of follow-up, and all transmitters 1ki radiate simultaneously with the total C11 chrono-s for the joystick object.

During the pauses between the two and the second pulses of the transmitters, correspondents working also in a pulsed mode are received. At the same time, the effect of transmitters on receivers located in the same object with them is excluded.

The proposed method can provide multichannel operation, if the transmitter also emits pulses that carry information transmitted over other similar channels.

channels. In addition, the proposed method allows for duplex radio communication.

The transmitter (Fig. 1, a) is designed to transmit speech signals occupying

frequency spectrum 300-3400 Hz. The signals from microphone i are fed through a low pass filter 2 and a low frequency amplifier 3 and a delay line 4 having K evenly spaced taps. The distance in time between signals, sijemashi from adjacent taps

- T

-to

where T is HeiKOTOipbifl interval | V | remeni, equal to the longest time line delay.

The delay line allows the coincidence of the TO time of the CI of the transmitted signal oTpesiKOiB of the transmitted signal with the last K-th interval of the interval T during the time t (Fig. 2, a). After passing through the delay line, all signals, with the exception of the signal taken from the first branch, are subjected to frequency conversion in the frequency conversion unit 5;

- the signal from the second branch of the delay line moves to the width of the spectrum in the direction of high frequencies;

- | Cngnal from the third branch of the delay line, two widths of the spectrum in the direction of high frequencies;

-signal from the fourth branch of the line of delay KGI-three width of the spectro, etc.

The converted signals are fed to the inputs of the addition circuit 6. The group spectrum at the output of the addition circuit is shown in FIG. 2.6. Thus, the IB of each frequency iodine of the group spectrum contains the same information with a delay of the time shift relative to the previous subchannel.

At the output of the pulse modulator 7, a pulse signal of duration t is received, which contains information about the input signal for the entire pulse following period T and controls the operation of the autogenerator 8. Synchronism of operation is provided by synchronization device 9. After amplification in the exhaust stage 10, the signal is emitted by the antenna .

At the time of the transmitter emitting a radio station, the I1-pulse with the duration t is the receiver of the radio station locked. Reception is carried out between transmitter pulses during the time Tt (Fig. 2, c).

In the receiver (Fig. 1.6), radio pulses from antenna 12 are transmitted through a common radio path 13 to a time selector 14 and a synchronization device 15. The common radio frequency circuit produces amplification and frequency selection of radio pulses and is built according to a superheterodyne circuit. The components of the K frequency bands contained in the selected pulse

the duration t is distributed over the corresponding frequency subchannels in the frequency division device 16 and aa taps of the delay line 17 are supplied (the order of marking the taps of the delay line at the receiving staron

reverse relative to transmitter). Restored continuous signal of duration T from the output of the delay line 17 is fed to the input of the low-frequency amplifier 18 and then through the low-pass filter 19 to the phones 20.

The magnitude of the impulse period G is determined by the transmitter pulse duration m and the number of frequency subchannels K used to transmit one speech signal by the proposed method.

The minimum value of the pulse duration t, i.e. Tmin, must be chosen from

CONDITIONS

: 10 & .FC

where Afc is the width of the spectrum of the transmitted speech signal.

Thus, with & Fc 3, l kHz, msak is required.

The number K depends on the number of subscribers located in one object and their activity. Need to strive to

/WITH

t

and select the upper limit of the period of the AND pulses T for reasons of technical implementation of the delay line and ease of conversation.

Subject invention

The method of transmitting / receiving radio telephony signals with time diversity and dividing the speech signal into separate time samples, characterized in that, in order to reduce mutual interference, each time sample is delayed by a time equal to the sample duration multiplied by

its sequence number, transform each sample in frequency so that the spectra of each sample overlap, and emit all samples at the same time, and receive signals from other radio stations in pauses

between radiation.

18

FIG. T

nineteen

20

TO

gd

T-Htr

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