SU499645A1

SU499645A1 - Device for demodulating signal with m-phase shift keying

Info

Publication number: SU499645A1
Application number: SU1980545A
Authority: SU
Inventors: Виктор Леонидович Банкет; Владимир Николаевич Батраков
Original assignee: Одесский Электротехнический Институт Связи Имени А.С.Попова
Priority date: 1973-12-26
Filing date: 1973-12-26
Publication date: 1976-01-15

Description

1one

Известно устройство дл демодул ции сигнала с М-кратной фазовой манипул цией, содержащее узел формировани onoipHoro сигнала , последовательно соединенные М-2 удвоителей , выходы каждого из которых соответственно подключены ко входам каждого из М-2 фазовращателей.A device for demodulating a signal with an M-phase shift keying is known, which contains an onoipHoro signal shaping unit, connected in series to M-2 doublers, the outputs of each of which are respectively connected to the inputs of each of the M-2 phase shifters.

Однако в таком устройстве умножение частоты опорного сигнала нар ду с умножением частоты принимаемого сигнала с М-кратной фазовой манипул цией приводит к усложнению реализации устройства при больщой кратности манипул ции М и к снижению помехоустойчивости .However, in such a device, multiplying the frequency of the reference signal, along with multiplying the frequency of the received signal with an M-fold phase shift, makes it more difficult to implement the device with a large number of manipulations, M, and reduce noise immunity.

22

Устройство дл демодул ции сигнала с Мкратной фазовой манипул цией содерл ит вход 1 устройства, удвоители 2 частоты (М-2 удвоителей), фазовращатели 3 (М-2 фазовращателей ), блоки 4 определени пол рности в отсчетные моменты времени (М блоков), узел 5 формировани опорного сигнала п блок 6 формировани когерентных управл к дих нмпульсов .A device for demodulating a signal with multiple phase shift keying contains device input 1, frequency doublers 2 (M-2 doublers), phase shifters 3 (M-2 phase shifters), polarity determination units 4 at reference times (M blocks), node 5 forming a reference signal; n block 6; forming coherent controls for these pulses.

Устройство работает следуюпим образом.The device works as follows.

Claims

A device with multiple phase shift manipulation is fed to the input 1 of the device, which is recorded in the following form for the duration of the elementary parcel. The demodulation of the signal with the M multiple times phase shift manipulation is performed by determining the polarity of the received signal at certain points in time. The reference time to demodulate the signal in the first channel is determined from the expression J1 T 4 The reference time to demodulate the signal in the second channel is determined from the expression y (3) The subsequent channels with the number are demodulated by determining the polarity of the signal with phase shift which is obtained after doubling the frequency of the signal with multiple phase shift manipulation in (p-2) times. After doubling the frequency in (p-2), the signal has the form cos {2 - ()}. (4) The reference time for demodulating the signal in the g-th channel is determined from the expression T The reference times ti and t are one from the other for an interval equal to a quarter of the period of the carrier oscillation of the GM. A signal with an M-phase shift keying is applied to the signal inputs of the first and second polarity determination units 4 at reference times, on control inputs of which rectangular oscillations occur from block 6 shifted by one quarter of the period of the carrier oscillation signal with M phase manipulation. The oscillation phasing is performed by the node 5 forming the reference signal over a period, based on expressions (2), (3) and (5). As a result of the operation of the first and second polarity determination units 4, the binary information of the first and second channels at the reference time points at their outputs receives, respectively. At the same time, a signal from the input I of the device is fed to the first doubler 2 frequency, in which the frequency of the received signal is doubled with an M-phase shift keying. Since the output signal of a real frequency doubler has a parasitic phase shift, the first phase shifter 3 is connected to the output of the first block of frequency doubler 2, the output of which, in turn, is connected to the signal input of the third polarity detection unit 4 at reference times. The first phase shifter 3 orients the frequency doubled in signal so that the leading edge of the pulse sequence from the second output of coherent control pulse generation unit 6 coincides with the time tn defined by (5) for, resulting in the output of the third polarity determining unit 4 at reference times receive the third channel binary information. In a similar way, the demodulation of the binary information of the other channels is also obtained. The invention provides a device for demodulating a signal with multiple phase shift manipulation, comprising a reference signal generating unit connected in series by M-2 doublers, the outputs of each of which are respectively connected to the inputs of each of M-2 phase shifters, in order to improve noise immunity. , a coherent control pulse shaping unit and M polarity detection units are introduced into the device at the reference time points, with the signal inputs of each of the M polarity detection units and at reference times, respectively, are connected to the device input and outputs of the phase shifters, and the control inputs are connected to the output of the coherent control pulse generation unit, to the input of which the output of the reference signal generation unit is connected.