3 research outputs found
Second-Order Coding Rate of Quasi-Static Rayleigh-Product MIMO Channels
With the development of innovative applications that require high reliability
and low latency, ultra-reliable and low latency communications become critical
for wireless networks. In this paper, the second-order coding rate of the
coherent quasi-static Rayleigh-product MIMO channel is investigated. We
consider the coding rate within O(1/\sqrt(Mn)) of the capacity, where M and n
denote the number of transmit antennas and the blocklength, respectively, and
derive the closed-form upper and lower bounds for the optimal average error
probability. This analysis is achieved by setting up a central limit theorem
(CLT) for the mutual information density (MID) with the assumption that the
block-length, the number of the scatterers, and the number of the antennas go
to infinity with the same pace. To obtain more physical insights, the high and
low SNR approximations for the upper and lower bounds are also given. One
interesting observation is that rank-deficiency degrades the performance of
MIMO systems with FBL and the fundamental limits of the Rayleigh-product
channel approaches those of the single Rayleigh case when the number of
scatterers approaches infinity. Finally, the fitness of the CLT and the gap
between the derived bounds and the performance of practical LDPC coding are
illustrated by simulations