| dc.description |
Multiple-input multiple-output (MIMO) antenna technology is promising
for high-speed wireless communications without increasing the transmission band-
width. Space time coding (STC) is a scheme that employs multiple antennas to
increase transmission rate or to improve transmission quality. STC is used widely
in mobile cellular networks, wireless local area networks (WLAN) and wireless
metropolitan area networks (WMAN). However, there are still many unsolved or
partially solved issues in STC. In this thesis, I propose a new STC design from
cyclic design. I then propose a systematic method to design quasi-orthogonal
space time block codes (QOSTBC) for an arbitrary number of transmit antennas,
and derive the optimal constellation rotation angles to achieve full diversity. I also propose an analytical method to derive the exact error probabilities of orthogonal space time block codes (OSTBC). In order to improve the error performance, I
introduce an adaptive power allocation scheme for OSTBC. Combining STC with
continuous phase modulation (CPM) is an attractive solution for mobile commu-
nications for which power is limited. Thus, I apply OSTBC to binary CPM with
modulation index h = 0.5, and develop a simplified receiver for such scheme. Finally, I present a decoding method to reduce the complexity of QOSTBC without
degrading its error performance. |
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