Nearest Neighbor Decoding and Pilot-Aided Channel Estimation for Fading Channels Articles uri icon

publication date

  • August 2020

start page

  • 1

end page

  • 34

issue

  • 9, 971

volume

  • 22

International Standard Serial Number (ISSN)

  • 1099-4300

abstract

  • We study the information rates of noncoherent, stationary, Gaussian, and multiple-input multiple-output (MIMO) flat-fading channels that are achievable with nearest neighbor decoding and pilot-aided channel estimation. In particular, we investigate the behavior of these achievable rates in the limit as the signal-to-noise ratio (SNR) tends to infinity by analyzing the capacity pre-log, which is defined as the limiting ratio of the capacity to the logarithm of the SNR as the SNR tends to infinity. We demonstrate that a scheme estimating the channel using pilot symbols and detecting the message using nearest neighbor decoding (while assuming that the channel estimation is perfect) essentially achieves the capacity pre-log of noncoherent multiple-input single-output flat-fading channels, and it essentially achieves the best so far known lower bound on the capacity pre-log of noncoherent MIMO flat-fading channels. Extending the analysis to fading multiple-access channels reveals interesting relationships between the number of antennas and Doppler bandwidth in the comparative performance of joint transmission and time division multiple-access.

keywords

  • achievable rates; fading; high signal-to-noise ratio (snr); mismatched decoding; multiple-access channels; multiple antennas; nearest neighbor decoding; noncoherent; pilot-aided; channel estimation