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Information Gains of Packet Retransmissions Through Frequency-Selective Channels
Applied Math| Speaker: | Zhi Ding, University of California, Davis |
| Location: | 693 Kerr |
| Start time: | Tue, May 10 2005, 4:10PM |
We present new protocols for improving system performance in combining ARQ-induced packet retransmissions. These protocols focus mainly upon the signal processing processes at the physical layer. We focus on retransmission diversity in frequency-selective channels. A new hybrid ARQ protocol is presented for systems in frequency-selective fading environments. Packet retransmissions are combined via integrated MAP channel equalization. This equalization strategy has several advantages, including low computational complexity and improved receiver performance. Mapping diversity is easily incorporated into this protocol. A second ARQ protocol for multicarrier modulations (MCM) is studied that involves symbol interleaving and mapping diversity. As MCM creates a set of parallel memoryless channels, mapping diversity and joint demapping are easily applied. An analysis of the OFDM interleaving gain is also provided.