Optimizing two-way communication with feedback

Problem Statement and Motivation

• The utility of feedback has been studied under the assumption of perfect channel state information at the transmitter and receiver (CSITR).
• Feedback is usually considered in one-way data communication scenarios but is more accurately accounted for in two-way time-varying scenarios.
• We propose to extend the study of perfect one-way feedback to noisy feedback in two-way time-varying networks.
  • There are a number of tradeoffs particular to the two-way network setting; the exploration of these tradeoffs will increase packet efficiency

Technical Approach

• We develop a new framework for two-way networks with feedback. It captures time-variation of wireless channels, accounts for training, feedback, ARQ and data bits, and incorporates network-coding and collaboration in retransmitted bits.
• We evaluate the achievable throughputs in two-way point-to-point with feedback. We obtain the optimal packet resource allocations corresponding to different channel time-variation rates, noise powers, and receiver feedback protocols.
• We evaluate the achievable throughputs in MABC with feedback. It provides whether, when and how to use network coding and collaboration in retransmitting packets, and how to optimize protocol parameters.

Key Achievements and Future Goals

• Z. Ahmad, I. Ahmad, B. Smida and D. Love, “Analysis of Two-Unicast Network-Coded Hybrid- ARQ With Unreliable Feedback,” IEEE Transactions on Vehicular Technology, no.11, vol. 67, November 2018.
• B. Smida, M. Hossain, and Y. Zhao, “Optimization of pilot overhead in communication with ARQ-feedback,”, IEEE Transactions on on Wireless Communication Letters, December, 2015.
• H. Zhu, B. Smida, and D. Love, “An efficient network coding scheme for two-way communication with ARQ feedback,” Proc of IEEE ICC 2016, Kuala Lumpur, Maliysia, May 2016.
• B. Smida, N. Devroye and T. Li, “Optimization of Two-way Communication with ARQ Feedback,” Proc of IEEE ICC 2013, Budapest, Hungry, June 2013.
• M. Mousaei and B. Smida, “Optimizing Pilot Overhead for Ultra-Reliable Short-Packet Trans- mission,” Proc of IEEE ICC 2017, Paris, France, May 2017.
• H. Zhu, X. Gu, B. Smida and D. Love, “On Practical Network Coded ARQ for Two-way Wireless Communication,” Proc of IEEE ICC 2017, Paris, France, May 2017.