A unified treatment of optimum pilot overhead in multipath fading channels

Jindal, Nihar; Lozano Solsona, Angel

doi:http://dx.doi.org/10.1109/TCOMM.2010.083110.090696

A unified treatment of optimum pilot overhead in multipath fading channels

Citation

Jindal N, Lozano A. A unified treatment of optimum pilot overhead in multipath fading channels. IEEE transactions on communications. 2010; 58(10): 2939-2948. DOI 10.1109/TCOMM.2010.083110.090696

Abstract

The optimization of the pilot overhead in single-user wireless fading channels is investigated, and the dependence of this overhead on various system parameters of interest (e.g., fading rate, signal-to-noise ratio) is quantified. The achievable pilot-based spectral efficiency is expanded with respect to the fading rate about the no-fading point, which leads to an accurate order expansion for the pilot overhead. This expansion identifies that the pilot overhead, as well as the spectral efficiency penalty with respect to a reference system with genie-aided CSI (channel state information) at the receiver, depend on the square root of the normalized Doppler frequency. It is also shown that the widely-used block fading model is a special case of more accurate continuous fading models in terms of the achievable pilot-based spectral efficiency. Furthermore, it is established that the overhead optimization for multiantenna systems is effectively the same as for single-antenna systems with the normalized Doppler frequency multiplied by the number of transmit antennas.