Abstract:

A novel type of spreading access codes with set-wise zero correlation window (ZCW) is proposed for minimum orthogonal frequency shift multi-carrier direct spread code division multiple access (CDMA) system in which the carrier gap is half of the reciprocal of the chip cycle. The proposed codes are constructed through the direct product of some ZCW complementary codes and certain extend matrix. That is, each complementary code is extended to a set of codes. The access codes correlation property of the codes in one set lies on the extend matrix, nevertheless the ZCW still exists between any two codes in any different code sets. The receiver adopts joint detection only for a code-set rather than for all the codes. Simulation results show that data transmission rate can be improved by several times at the cost of 1-2 dB signal to noise ratio loss in multi-path fading channels.

Key words: multicarrier direct spread system, complementary code, zero correlation window, CDMA