Publications [#235965] of Robert Calderbank

Journal articles or Book chapters PUBLISHED

1. Wu, Y; Achtzehn, A; Petrova, M; Mähönen, P; Calderbank, R, On the effect of feedback delay on limited-rate beamforming systems, Globecom IEEE Global Telecommunications Conference (January, 2010), IEEE [doi]
   (last updated on 2026/01/17)

   Abstract:
   The use of beamforming to enable higher data rates in telecommunications is widely appreciated, but performance gains are typically calculated assuming delay-free feedback from the receiver and neglecting processing time. This paper introduces a mathematical framework based on outage probability that measures the extent to which current channel state information is accurate. Performance gains from beamforming can then be evaluated as a function of the currency of system state. Results are provided for Multiple Input Single Output (MISO) and for Multiuser Multiple Input Multiple Output (MU-MIMO) systems. Outage probabilities and effective diversity orders are calculated for widely used methods of beamforming such as Transmit Antenna Selection as a function of the speed of channel variation. ©2010 IEEE.