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The opportunistic cooperative diversity is promising to improve the capacity of the wireless communications because it yields the same diversity order as using all relay nodes while requires bandwidth for only one relay node. The more number of relay nodes we employ, the higher diversity order we obtain. From the results in the literature, the recently published paper conjectures that there exists...
Cooperative diversity techniques can improve the transmission rate and reliability of wireless networks. For systems employing such diversity techniques in slow-fading channels, outage probability and outage capacity are important performance measures. Existing studies have derived approximate expressions for these performance measures in different scenarios. In this paper, we derive the exact expressions...
Cooperative diversity is a useful technique to increase reliability and throughput of wireless networks. To analyze the performance gain from cooperative diversity, outage capacity is an important figure of merit that captures the inherent diversity-multiplexing trade-off in cooperative diversity schemes. In this paper we derive the outage capacity for several cooperative diversity schemes in decode-and-forward...
This paper proposes a new space-frequency (SF) code construction scheme that can fully exploit both spatial and frequency diversities while providing great coding advantage and maintaining high bandwidth efficiency for MIMO-OFDM system operating in frequency-selective channels. The proposed SF code construction method is based on a class of trellis codes, where the trellis branches are labeled with...
This paper addresses the problem of optimizing the adaptive power allocation for data transmission over wireless communication fading channels using multiple transmit antennas with band-limited feedback channel. The objective of the optimization is to minimize the bit error rate (BER) subject to constraint on the average transmitted power. The chosen multi-antenna transmission scheme is the transmit...
This work proposes improved rate-1 full-diversity space-frequency block code (SFBC) designs that outperform the existing SFBC designs. It is observed that signal mapping for the existing rate-1 full-diversity SFBC designs can be improved. A simple mapping scheme is proposed here that greatly enhances the resulting performance of the SFBC scheme. The performance gains of the proposed codes are mathematically...
This paper describes how to construct a class of spaces-frequency (SF) codes by mapping the super-orthogonal space-time trellis (SOSTT) codes across OFDM subcarriers. Two mapping methods are employed: conventional repetition mapping and the proposed mapping methods with the design criteria of achieving full diversity including spatial and frequency at the maximum possible transmission rate. The proposed...
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