Asynchronous digital correlator and demodulators comprising such a correlator

Abstract

Abstract Asynchronous digital correlator making it possible to produce simpler demodulators than those of the prior art. For example, a demodulator for demodulating a complex signal consisting of two carriers (I, Q), in quadrature, whose spectrum is spread by a pseudo-random signal and which are modulated by an M-ary, Walsh code, comprises:… - a chain of registers (41) for storing 256 bits of a pseudo-random signal (PN);… - a multiplexer (23) for time-multiplexing the processing of the two carriers (I, Q);… - a correlation macro-cell (43) chain (42) having a pipeline structure permitting a time-multiplexing, and having intermediate outputs making it possible to have available partial correlation values relating to 16 moments (CPI0, ..., CPI15; CPQ0, ..., CPQ15);… - a device (32) for calculating linear combinations of the partial correlation functions, in order to calculate 2 correlation functions (FIi, FQi) corresponding to the 2 carriers (I, Q), for each M-ary code;… - a demultiplexing and calculating device (33) for calculating the modulus of the correlation function (Fi) for each of the Walsh codes which may modulate the signal to be demodulated;… - a device (34) for selecting the largest value (Fj) from the correlation functions, and for selecting the corresponding datum (j). …<??>Application to PSK, MSK and QPSK demodulators. …<IMAGE>…

Inventors

• 👤 Vincent Albrieux
• 👤 Didier Soufflet

Bibliographic Details