RU2045127C1 - Device for compression of wide-band discrete frequency-shift signal with continuous phase and manipulation index d=0 - Google Patents

Abstract

5. FIELD: radio engineering. SUBSTANCE: device has frequency doubler 1, former 2 of present values of keying frequency, narrow-band filter 3, first and second dividers 4 and 5, multiplier 6 and additional multiplier 7. EFFECT: reduced threshold of device, increased noise immunity of receiver and improved authenticity of reception.

Description

 The invention relates to radio engineering and can be used in coherent communication receivers, radio measuring systems and special equipment that use discrete frequency-manipulated signals with a continuous phase (DFMN) to detect a signal, synchronize the demodulation process, Doppler measurements, AGC, etc.

 Closest to the invention is a signal demodulator circuit for manipulating with maximum shift, comprising a frequency doubler, two parallel-coupled low-frequency FAP loops (tuned to doubled sampling frequencies respectively), two frequency dividers and a clock multiplier.

≫ 1) и недостаточную помехозащищенность.However, this circuit has a high threshold (

≫ 1) and insufficient noise immunity.

 The purpose of the invention is to lower the threshold, increase the noise immunity of the clock frequency generating circuit, and increase the reliability of information decoding.

 The drawing shows a diagram of a compression device for a broadband discrete frequency-manipulated signal.

The device contains a frequency doubler 1, a shaper of 2 current values of the sampling frequencies, including six multipliers 2 ₁ ⁰ , 2 ₁ ¹ , 2 ₃ ⁰ , 2 ₃ ¹ , 2 ₄ ⁰ , 2 ₄ ¹ , two narrow-band filters 2 ₂ ⁰ and 2 ₂ ¹ and a reference oscillator 2 ₅ , a narrow-band filter 3, the first and second frequency dividers 4 and 5, a multiplier 6 and an additional multiplier 7.

 The device operates as follows.

t+a_k

[t-(k-1)τ_д]+πD

a

, где Δω отклонение частоты дискрета от средней;
D

τ_д индекс манипуляции;
τ_д длительность дискрета;
a_k∈{+1, -1} знакопеременный множитель;
ω_ср

средняя частота сигнала;
k порядковый номер дискрета в ПСП, поступает на удвоитель 1 частоты. В результате гладкий спектр входного сигнала преобразуется в новый спектр на удвоенной частоте, в котором кроме гладкой модуляционной составляющей образуются две дискретные составляющие на частотах 2ω₁ и 2ω_о
S(t, 2ω)=cos

2ω_срt+a_k

[t-(k-1)τ_д]

.The input described by the formula
S (t, ω) = cos

t + a _k

[t- (k-1) τ _d ] + πD

a

where Δω is the deviation of the sampling frequency from the average;
D

τ _d manipulation index;
τ _{d the} duration of the discrete;
a _k ∈ {+1, -1} an alternating factor;
ω _cf

average signal frequency;
k is the serial number of the discrete in the memory bandwidth, fed to the frequency doubler 1 As a result, the smooth spectrum of the input signal is converted to a new spectrum at twice the frequency, in which, in addition to the smooth modulation component, two discrete components are formed at frequencies 2ω ₁ and 2ω _о
S (t, 2ω) = cos

2ω _cp t + a _k

[t- (k-1) τ _d ]

.

The output signal of the doubler 1 is fed to the input of the additional 7 and to the shaper 2. At the output of the two-channel shaper 2, two sinusoidal oscillations are regenerated at doubled values of the sampling frequencies, the frequency of each of which is divided into two in the dividers 4 and 5. The generated oscillations at frequencies ω ₀ and ω ₁ are fed to both inputs of the multiplier 60, as a result of which a sinusoidal oscillation is formed at its output with a frequency of ω ₀ + ω ₁ = 2ω _cp (due to coherence).

2ω_срt+a_k

[t-(k-1)τ_д]

cos2ω_срt=

cos

t +

cos

4ω_срt+a_k

[t-(k-1)τ_д]

. Первое слагаемое

cos

t не содержит в аргументе знакопеременного множителя a_k, а его спектр представляет собой дискретную линию на тактовой частоте выходной монохроматический сигнал с С/Ш>1. Подавление спектра второго слагаемого на частотах в окрестности 4 ω_cp осуществляется узкополосным фильтром 3.An additional multiplier implements the operation of multiplying the input signal at a double frequency by a continuous oscillation with a frequency of 2 ω _cp
cos

2ω _cp t + a _k

[t- (k-1) τ _d ]

cos2ω _cp t =

cos

t +

cos

4ω _cp t + a _k

[t- (k-1) τ _d ]

. First term

cos

t does not contain an alternating factor a _k in the argument, and its spectrum is a discrete line at the clock frequency, the output monochromatic signal with S / N> 1. The spectrum of the second term is suppressed at frequencies in the vicinity of 4 ω _cp by a narrow-band filter 3.

Claims (1)

 DEVICE FOR COMPRESSING A WIDE BAND DISCRETE FREQUENCY-MANIPULATED SIGNAL WITH A CONTINUOUS PHASE AND MANIPULATION INDEX D = 0.5, containing a frequency doubler, the output of which is connected to the input of the driver of the current values of the frequency of the manipulation, the outputs of which are connected to the second inputs by the inputs of the connectors the fact that an additional multiplier and a narrow-band filter are introduced in series with it, while the output of the frequency doubler and the output of the multiplier are connected to odes additional multiplier.