Patent ID: 7103061

Claim:
A CDMA communication system comprising: at least one primary station( 2 ) and a plurality of secondary stations ( 4 ), the primary station ( 2 ) and the secondary stations ( 4 ) exchanging CDMA signals ( 18 ) via a communication medium ( 6 ), the secondary stations ( 4 ) each comprising: a modulator ( 10 ) for modulating a respective data signal ( 16 ) with a respective code word ( 14 ) in order to obtain a respective CDMA signal ( 18 ), the modulator being embodied so as to modulate the respective data signal ( 16 ) with an initial code word until synchronization with the primary station ( 2 ) is obtained, the modulator ( 10 ) being further embodied so as to modulate the respective data signal ( 16 ) with a respective final code word after synchronization with the primary station ( 2 ) has been obtained, wherein the initial code word is substantially orthogonal to the final code words for every possible time shift of the initial code word.