# Near-field Ultra-wideband mmWave Channel Characterization Using Successive Cancellation Beamspace UCA Algorithm

## TL;DR

This paper introduces a low-cost, near-field beamspace UCA algorithm for ultra-wideband mmWave channel estimation, effectively detecting multipath angles and delays in 5G systems with large antenna arrays.

## Contribution

It proposes a novel, computationally efficient beamforming algorithm that works in near-field conditions for ultra-wideband systems, addressing limitations of traditional far-field assumptions.

## Key findings

- Algorithm accurately detects multipath components in simulations.
- Experimental results validate robustness and effectiveness.
- Outperforms existing state-of-the-art methods.

## Abstract

Of the wide palette of 5G features, ultra-wide bandwidth and large-scale antenna configuration are regarded as the essential enabling technology components at millimeter wave (mmWave) communication. Accurate knowledge of delay and angle information of multipath components is essential for many applications in mmWave systems. There is a strong need for a low computation-cost channel estimation algorithm for such systems, where typically adopted far-field and narrowband assumptions might be violated. In this work, a generic yet novel beamspace uniform circular array (UCA) beamforming algorithm with successive cancellation scheme is proposed to jointly detect the impinging angle and delay of the multipath components. The proposed algorithm is computationally cheap and it works for ultra-wideband (UWB) systems in the near-field conditions. Both numerical simulations and experimental validation results are provided to demonstrate the effectiveness and robustness of the proposed algorithm, compared to the state-of-art works.