Abstract: Acquisition method for phase recovery in a direct sequence code division multiple access communications system, in which a first phase alignment is made at the end of a first symbol period (S1), subsequently a new mean phase shift is detected at the end of a second symbol period (S2) and a second phase correction is applied, either integrally at 100%, or preferentially enhanced at 150%. At said instant, a phase shift gradient is also estimated, associated with a shift in frequency, and a frequency correction is applied, said correction being applied and maintained for the duration of a subsequent symbol (S3). A final phase alignment is required at the end of a third symbol, if the 100% phase correction approach is adopted in the second symbol.

Abstract: A multiline PCM interface for signal processing is of particular application in cordless digital telephony, type DECT, with echo cancelling and ADPCM type voice encoding. The interface incorporates a set of ADPCM encoders (COD) and ADPCM decoders (DEC), digital-to-analogue (D/A) converters and analogue-to-digital converters (A/D). The outputs of the ADPCM decoders (DEC) and the analogue-to-digital converters (A/D) are joined to form a PCM output bus (BPO), the inputs of the digital-to-analogue (D/A) converters and ADPCM encoders (COD) are joined together to form a PCM input bus (PI). The interface also includes signal processing means (MSP) which receive data bursts from the PCM output bus (BPO) and applies these same bursts to the PCM input bus (PI) with a delay of one frame and echo-free. A synchronism generator (SYGEN) allocates consecutive time slots to converters involved in the same conversation, which therefore employ the same signal processor (DSP) to perform associated conference operations.