Low SNR Capacity of Fading Channels with Peak and Average Power Constraints
<|reference_start|>Low SNR Capacity of Fading Channels with Peak and Average Power Constraints: Flat-fading channels that are correlated in time are considered under peak and average power constraints. For discrete-time channels, a new upper bound on the capacity per unit time is derived. A low SNR analysis of a full-scattering vector channel is used to derive a complimentary lower bound. Together, these bounds allow us to identify the exact scaling of channel capacity for a fixed peak to average ratio, as the average power converges to zero. The upper bound is also asymptotically tight as the average power converges to zero for a fixed peak power.   For a continuous time infinite bandwidth channel, Viterbi identified the capacity for M-FSK modulation. Recently, Zhang and Laneman showed that the capacity can be achieved with non-bursty signaling (QPSK). An additional contribution of this paper is to obtain similar results under peak and average power constraints.<|reference_end|>
@article{sethuraman2006low,
    title={Low SNR Capacity of Fading Channels with Peak and Average Power
  Constraints},
    author={Vignesh Sethuraman, Bruce Hajek},
    journal={arXiv preprint arXiv:cs/0604049},
    year={2006},
    archivePrefix={arXiv},
    eprint={cs/0604049},
    primaryClass={cs.IT math.IT}
}