Abstract
Channel state information (CSI) at the transmitter can be used to adapt transmission rate or antenna gains in multi-antenna systems. We propose a rate-adaptive M-QAM scheme equipped with orthogonal space-time block coding with simple outdated, finite-rate feedback over independent flat fading channels. We obtain closed-form expressions for the average BER and throughput for our scheme, and analyze the effects of possibly delayed feedback on the performance gains. We derive optimal switching thresholds maximizing the average throughput under average and outage BER constraints with outdated feedback. Our numerical results illustrate the immunity of our optimal thresholds to delayed feedback.
Original language | English (US) |
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Pages (from-to) | 290-295 |
Number of pages | 6 |
Journal | IEEE Transactions on Wireless Communications |
Volume | 5 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2006 |
Keywords
- Adaptive modulation
- multi-input multi-output
- orthogonal space-time block coding
- quadrature amplitude modulation
- systems
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics