On the design of reliable multiple antenna communication systems

Multiple-input multiple output (MIMO) radio systems have seen a great deal of attention since Telatar [Tel95], Foschini and Gans [FG98] showed that exploiting the multiple transmit/receive antenna increases the outage capacity. The MIMO system achieves the diversity without sacrificing the very limited time and frequency. This thesis looks at the two aspects in the design of MIMO communication systems: MIMO signaling and nonlinear distortion manipulation in MIMO.; In MIMO signaling the space-time code will be mainly dealt with. Firstly, super-orthogonal space-time block code (STBC) will be introduced. The code construction is based on the expansion of orthogonal block code via a unitary matrix transformation. By expanding the orthogonal block code, both the code rate can be increased and the performance improved in terms of E b/N0, with a moderate increase of the receiver complexity. Exploiting the partial orthogonality of super-orthogonal STBC, a simplified maximum likelihood decoder will be derived. The capacity of super-orthogonal STBC can be gradually increased toward that of multiple-input multiple-output system with finite constellation. Performance is compared with several quasi-orthogonal block codes in computer simulation. It will be shown that super-orthogonal STBC outperforms all the existing quasi-orthogonal STBCs with four transmit antennas in most cases.; Secondly, space-time multiple TCM (ST-MTCM) code will be studied. Improved ST-MTCM codes via a systematic expansion of the STBC is presented especially for two transmit antennas. Starting from orthogonal STBC, the STBC set is expanded into super-orthogonal STBC, and further expanded up to spatial multiplexing in the case of BPSK and QPSK constellations. Exploiting the expanded set of STBCs as the number of states increase, improved full diversity ST-MTCM codes can be designed by increasing the coding gain and Euclidean distance of pairwise errors.; Lastly, nonlinear distortion problem in MIMO will be studied. High PAPR causes nonlinear distortion from the high power amplifier and results in performance degradation. Instead of separate peak-to-average power (PAPR) reduction on each transmit antenna, a new PAPR reduction scheme in multiple transmit antenna environments is presented. By applying a relevant unitary rotation across signals in each transmit antenna, the peak power in one transmit antenna can be distributed over other transmit antennas, which reduces overall PAPR of the multiple transmit antenna system. This scheme doesn't require any side information to decode the signal in the receiver, enabling throughput-lossless PAPR reduction. Furthermore, there is no increase in the complexity of the receiver.