Quinn Li

Transmit Diversity With More Than Two Antennas

Recently, a new form of transmit diversity has been developed and included for cdma2000, the third generation successor for IS-95 code division multiple access (CDMA) systems. This transmit diversity scheme was developed by Bell Laboratories and uses Space-Time coding techniques. This paper presents performance results of this new transmit diversity method, termed space-time spreading, and investigates ”open-loop” improvements to the scheme which use more than two antennas. Additionally, we investigate the performance improvements possible with closed loop techniques.

Channel coding performance in cdma2000 systems

Channel coding performance in a third generation mobile communication system is investigated in this paper. Specifically, the channel coding methods adopted in the cdma2000 standard along with the decoding procedures are described. The forward link performance of a cdma2000 system using both turbo codes and convolutional codes are studied.

Bandwidth-efficient trellis-coded modulation schemes with prescribed decoding delay

A class of trellis-coded modulation schemes whose Viterbi decoder optimally decodes observing a prescribed number of intervals is introduced. For a fixed decoding delay, it is shown that the minimum Euclidean distance of the resulting schemes is upper bounded by that of MSK. Signals that achieve this upper bound and maximize the power within a given bandwidth are found.