Relay Architectures for 3GPP LTE-Advanced

EURASIP Journal on Wireless Communications and Networking
Volume 2009 (2009), Article ID 618787, 14 pages
doi:10.1155/2009/618787

Research ArticleRelay Architectures for 3GPP LTE-Advanced

Steven W. Peters, Ali Y. Panah, Kien T. Truong, and Robert W. HeathDepartment of Electrical and Computer Engineering, The University of Texas at Austin, 1 University Station C0803, Austin, TX 78712-0240, USA

Received 17 February 2009; Accepted 31 May 2009

Academic Editor: Angel LozanoCopyright © 2009 Steven W. Peters et al.

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

AbstractThe Third Generation Partnership Project’s Long Term Evolution-Advanced is considering relaying for cost-effective throughput enhancement and coverage extension. While analog repeaters have been used to enhance coverage in commercial cellular networks, the use of more sophisticated fixed relays is relatively new. The main challenge faced by relay deployments in cellular systems is overcoming the extra interference added by the presence of relays. Most prior work on relaying does not consider interference, however. This paper analyzes the performance of several emerging half-duplex relay strategies in interference-limited cellular systems: one-way, two-way, and shared relays. The performance of each strategy as a function of location, sectoring, and frequency reuse are compared with localized base station coordination. One-way relaying is shown to provide modest gains over single-hop cellular networks in some regimes. Shared relaying is shown to approach the gains of local base station coordination at reduced complexity, while two-way relaying further reduces complexity but only works well when the relay is close to the handset. Frequency reuse of one, where each sector uses the same spectrum, is shown to have the highest network throughput. Simulations with realistic channel models provide performance comparisons that reveal the importance of interference mitigation in multihop cellular networks.1. Introduction  The Third  Generation Partnership Program’s Long-Term Evolution Advanced (3GPP-LTE-Advanced) group is developing  a new standard for mobile broadband access that will meet the throughput and coverage requirements of a fourth generation cellular technology [1]. One of the main challenges faced by the developing standard is providing high throughput at the cell edge. Technologies like multiple input multiple output (MIMO), orthogonal frequency division multiplexing  (OFDM), and advanced error control codes enhance per-link throughput but do not inherently mitigate the effects of interference. Cell edge performance is becoming more important as cellular systems employ higher bandwidths with the same amount of transmit power and use higher carrier frequencies with infrastructure designed for lower carrier frequencies [2]. One solution to improve coverage is the use of fixed relays, pieces of infrastructure without a wired backhaul connection, that relay messages between the base station (BS) and mobile stations (MSs) through multihop communication [3–11]. more

This article demonstrates the advantages of cellular repeater, or cell phone booster usage in areas where signal strength may be inadequate.