Joint Doppler and Channel Estimation with Nested Arrays for Millimeter Wave Communications

TL;DR

This paper introduces a novel joint Doppler and channel estimation method for mmWave communications using nested arrays, which improves accuracy and reduces complexity without discretizing the angle space.

Contribution

It proposes a new joint estimation technique leveraging nested arrays and covariance fitting, eliminating model mismatch and enhancing performance in high-speed scenarios.

Findings

Effective joint Doppler and channel estimation demonstrated

Reduces computational complexity via dual problem formulation

Outperforms existing methods in simulations

Abstract

Channel estimation is essential for precoding/combining in millimeter wave (mmWave) communications. However, accurate estimation is usually difficult because the receiver can only observe the low-dimensional projection of the received signals due to the hybrid architecture. We take the high speed scenario into consideration where the Doppler effect caused by fast-moving users can seriously deteriorate the channel estimation accuracy. In this paper, we propose to incorporate the nested array into analog array architecture by using RF switch networks with an objective of reducing the complexity and power consumption of the system. Based on the covariance fitting criterion, a joint Doppler and channel estimation method is proposed without need of discretizing the angle space, and thus the model mismatch effect can be totally eliminated. We also present an algorithmic implementation by solving the dual problem of the original one in order to reduce the computational complexity. Numerical simulations are provided to demonstrate the effectiveness and superiority of our proposed method.