Analysis of large area synchronous codedivision multiple access (LAS-CDMA)

Abstract

Large area synchronous code-division multiple access (LAS-CDMA) is a proposed fourth generation cellular standard. Similar to cdma2000, the distinguishing feature of LAS-CDMA is the new set of spreading codes used to separate users in the wireless channel. This thesis examines the properties of the new spreading codes. Unlike Walsh functions, which are orthogonal only when perfectly synchronized, LAS-CDMA spreading codes are orthogonal when synchronized within a nine-chip interference-free time window. The interference-free time window allows LAS-CDMA to transmit the forward link and reverse link over the same frequency band. The primary LAS-CDMA data channels are examined. LAS-CDMA uses a separate set of modulation and coding rate combinations for voice and data communications. Analysis of the effect of a tone jammer on the modulation and coding rate combinations is presented. Also, the ease with which LAS-CDMA can be intercepted is examined, and the security of LAS-CDMA is analyzed.