Reconfigurable Antennas, Preemptive Switching and Virtual Channel Management

This article considers the performance of wireless communication systems that utilize reconfigurable or pattern-dynamic antennas. The focus is on finite-state channels with memory and performance is assessed in terms of real-time behavior. In a wireless setting, when a slow fading channel enters a deep fade, the corresponding communication system faces the threat of successive decoding failures at the destination. Under such circumstances, rapidly getting out of deep fades becomes a priority. Recent advances in fast reconfigurable antennas provide new means to alter the statistical profile of fading channels and thereby reduce the probability of prolonged fades. Fast reconfigurable antennas are therefore poised to improve overall performance, especially for delay-sensitive traffic in slow-fading environments. This potential for enhanced performance motivates this study of the temporal behavior of point-to-point communication systems with reconfigurable antennas. Specifically, agile wireless communication schemes over erasure channels are analyzed; situations where using reconfigurable antennas yield substantial performance gains in terms of throughput and average delay are identified. Scenarios where only partial state information is available at the receiver are also examined, naturally leading to partially observable decision processes.