Multiuser Detection
TDD-CDMA for Wireless Communications
TDD-CDMA for Wireless Communications
Pre-equalization Techniques for Downlink and Uplink TDD MC-CDMA Systems
Wireless Personal Communications: An International Journal
Probability and Random Processes For EE's (3rd Edition)
Probability and Random Processes For EE's (3rd Edition)
Fast antenna subset selection in MIMO systems
IEEE Transactions on Signal Processing
A novel prefiltering technique for downlink transmissions in TDD MC-CDMA systems
IEEE Transactions on Wireless Communications
Adaptive code allocation for interference management on the downlink of DS-CDMA systems
IEEE Transactions on Wireless Communications
Spread-signature CDMA: efficient multiuser communication in the presence of fading
IEEE Transactions on Information Theory
IEEE Journal on Selected Areas in Communications
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This paper proposes a hybrid transmission technique based on adaptive code-to-user allocation and linear precoding for the downlink of phase shift keying (PSK) based multi-carrier code division multiple access (MC-CDMA) systems. The proposed scheme is based on the separation of the instantaneous multiple access interference (MAI) into constructive and destructive components taking into account the dependency on both the channel variation and the instantaneous symbol values of the active users. The first stage of the proposed technique is to adaptively distribute the available spreading sequences to the users on a symbol-by-symbol basis in the form of code-hopping with the objective to steer the users' instantaneous crosscorrelations to yield a favourable constructive to destructive MAI ratio. The second stage is to employ a partial transmitter based zero forcing (ZF) scheme specifically designed for the exploitation of constructive MAI. The partial ZF processing decorrelates destructive interferers, while users that interfere constructively remain correlated. This results in a signal to interference-plus-noise ratio (SINR) enhancement without the need for additional power-per-user investment. It will be shown in the results section that significant bit error rate (BER) performance benefits can be achieved with this technique.