A discrete-time Wiener phase noise channel with an integrate-and-dump
multi-sample receiver is studied. An upper bound to the capacity with an
average input power constraint is derived, and a high signal-to-noise ratio
(SNR) analysis is performed. If the oversampling factor grows as
SNRα for 0≤α≤1, then the capacity pre-log is at
most (1+α)/2 at high SNR.Comment: 5 pages, 1 figure. To be presented at IEEE Inf. Theory Workshop (ITW)
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