Uplink Channel Estimation for Multi-user OFDM-based Systems

• Published in: Wireless personal communications Vol. 47; no. 1; pp. 125 - 136
• Main Authors: Ribeiro, Carlos, Fernández-Getino Garcia, M. Julia, Gil Jiménez, Víctor P., Gameiro, Atílio, García Armada, Ana
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.10.2008; Springer
• Subjects: Applied sciences; Communications Engineering; Computer Communication Networks; Engineering; Equipments and installations; Exact sciences and technology; Mobile radiocommunication systems; Networks; Radiocommunications; Signal,Image and Speech Processing; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Multi-user; OFDM; Uplink; Channel estimation; Mobile radiocommunication; Multiple access; Parameter estimation; Wireless telecommunication; Carrier to noise ratio; Wide band transmission; Subcarrier; Learning; Time domain method; Wide band; Simulation; Pulse response; Telecommunication channels; Orthogonal frequency division multiplexing; Feasibility; Delay time
• ISSN: 0929-6212; 1572-834X
• DOI: 10.1007/s11277-007-9396-7

In this paper we propose a simple, yet flexible and efficient, channel estimator for the uplink in broadband orthogonal frequency division multiplexing (OFDM) systems. The processing is performed in the time-domain, by extracting the Channel’s Impulse Response (CIR) for each user from a joint training signal. In this OFDM system, the pilot sequence we advocate, where all users share the same pilot sub-carriers, consists of one OFDM-symbol endowed with time-shifted properties per user, which isolates each user’s CIR and is robust against multi-user interference. The feasibility of our approach is substantiated by system simulation results obtained using BRAN-A broadband mobile wireless channel model.