METHOD FOR RECEPTION OF BINARY PHASE-SHIFT KEYED SIGNALS FOR SHIFT OF 0, 90, 180, 270 DEGREES WITH PHASE-DIFFERENCE MODULATION AND DEVICE WHICH IMPLEMENTS SAID METHOD Russian patent published in 1999 - IPC

FIELD: radio and wire communication lines. SUBSTANCE: method involves binary sampling {0, 1} of low-frequency filtered signals in both quadrature orthogonal channels (X, Y) using non-coherent receiver. Since central frequency of local oscillator in receiver differs from frequency of local oscillator of transmitter, received signal vector (X_n,Y_n) on coordinate plane (X, Y) turns slowly with respect to vector of local oscillator of receiver. When projection of vector of received signal crosses zero on orthogonal coordinate axes, elimination of false triggering of comparator in vicinity of zero and transmission of this triggering to output of receiver are prevented by comparison of absolute value of filtered low-frequency signal to given threshold value U_thr in each quadrature channel. Results of comparison provides two quadrature operators F(x) and F(y), which have binary samples {0, 1}. If absolute values of low-frequency signals in both channels are greater than U_thr, then F(x)=F(y)=1. If absolute value of low-frequency filtered signal in one channel is less than U_thr, then F(x)=F(y), i.e. F(x)=1, F(y)=0 or F(x)=0, F(y)=1. Also, if F(x)=1, F(y)=0, then absolute value of filtered low- frequency signal is near maximal because of property of orthogonality in channel X at this moment; if F(x)=0, F(y)=1, this is true for channel Y. Values of binary samples in both channels in current and previous bits (X(n-1)_s,Y(n-1)_s,X_ns,Y_ns and quadrature operators F(x) and F(y) are used for judging phase shift by one of four values 0, π/2,π,3π/2. Device which implements said method is designed as optimal non- coherent detector of phase-shift keyed signals for shift of 0, 90, 180, 270 degrees with introduced two comparators, two comparison circuits, special or and corresponding connections. EFFECT: increased stability to noise, simplified design. 2 cl, 8 dwg