Abstract
This paper explores the performance of time-domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) systems operated under rapidly time-varying mobile channels. Since a rapidly time-varying channel contains more unknown channel coefficients than the number of observations, the mobile channel can conveniently be modeled with the discrete Legendre polynomial basis expansion model to reduce the number of unknowns. The linear minimum mean square error (LMMSE) estimate can be exploited for channel estimation on inter-block-interference-free received signal samples owing to transmitting pseudo-noise (PN) sequences. In conventional TDS-OFDM systems, the channel estimation performance is limited due to estimating channel responses only from the beginning part of the channel. Therefore, a new system model named "partitioned TDS-OFDM system" is proposed to improve the system performance by inserting multiple PN sequences to the middle and end parts of the channel as well. In addition to providing the reconstruction error performance, Bayesian Cramer-Rao lower bound is derived analytically. Also, the LMMSE-based symbol detection is employed. To alleviate the negative effects of inter-carrier-interference (ICI) occuring in mobile channels, ICI cancellation is applied to enhance the detection performance. The simulation results demonstrate that the proposed TDS-OFDM system is superior to the conventional system and its corresponding performance is able to approach the achievable lower performance bound.
| Original language | English |
|---|---|
| Article number | 8490845 |
| Pages (from-to) | 8123-8135 |
| Number of pages | 13 |
| Journal | IEEE Transactions on Wireless Communications |
| Volume | 17 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2018 |
Bibliographical note
Publisher Copyright:© 2018 IEEE.
Funding
Manuscript received May 25, 2018; revised September 19, 2018; accepted September 24, 2018. Date of publication October 12, 2018; date of current version December 10, 2018. This work was supported by the Scientific and Technological Research Council of Turkey (TÜB˙TAK) under Project 114E298. The associate editor coordinating the review of this paper and approving it for publication was N. Yang. (Corresponding author: Mehmet Bas¸aran.) M. Bas¸aran and H. A. Çırpan are with Istanbul Technical University, 34467 Istanbul, Turkey (e-mail: [email protected]; [email protected]).
| Funders | Funder number |
|---|---|
| Türkiye Bilimsel ve Teknolojik Araştirma Kurumu | 114E298 |
Keywords
- basis expansion model (BEM)
- Channel estimation
- rapidly time-varying mobile channels
- symbol detection
- time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM)