Optimal Pilot Symbols Ratio in terms of Spectrum and Energy Efficiency in Uplink CoMP Networks

TL;DR

This paper optimizes the ratio of pilot symbols in uplink CoMP networks to enhance spectrum and energy efficiency, considering channel estimation errors and backhaul limitations, with derived closed-form solutions validated by simulations.

Contribution

It introduces a novel optimization of pilot symbols ratio in uplink CoMP networks accounting for practical imperfections, providing closed-form solutions for SE and EE maximization.

Findings

Optimized pilot ratio improves spectrum efficiency.

Optimized pilot ratio reduces energy consumption.

Closed-form expressions enable practical implementation.

Abstract

In wireless networks, Spectrum Efficiency (SE) and Energy Efficiency (EE) can be affected by the channel estimation that needs to be well designed in practice. In this paper, considering channel estimation error and non-ideal backhaul links, we optimize the pilot symbols ratio in terms of SE and EE in uplink Coordinated Multi-point (CoMP) networks. Modeling the channel estimation error, we formulate the SE and EE maximization problems by analyzing the system capacity with imperfect channel estimation. The maximal system capacity in SE optimization and the minimal transmit power in EE optimization, which both have the closed-form expressions, are derived by some reasonable approximations to reduce the complexity of solving complicated equations. Simulations are carried out to validate the superiority of our scheme, verify the accuracy of our approximation, and show the effect of pilot symbols ratio.