Capacity enhancement of CDMA cellular systems by two-hop relaying

A routing algorithm, utilizing two-hop relaying when necessary, is proposed to enhance the capacity of CDMA cellular systems under heavy traffic load condition. Up to now, multihop transmissions are mainly applied to decrease the transmit power of each mobile station or to extend the cell coverage area. Here, in this paper, its potential benefit is studied that the multihop relaying and spatial frequency reuse might increase the network capacity. A condition for interference reduction by changing some single-hop connections to two-hop connections is analyzed and an efficient routing scheme for two-hop code division multiple access (CDMA) cellular systems to reduce co-channel interference at the base station is proposed. Simulation results indicate that by using proposed routing algorithm in combination with call admission control, the network capacity is increased even under heavy traffic condition.

[1]  H. H. Xia.  A simplified analytical model for predicting path loss in urban and suburban environments , 1997 .

[2]  Bijan Jabbari,et al.  Performance analysis of multihop packet CDMA cellular networks , 2001, GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270).

[3]  Yoshihiro Ishikawa,et al.  Capacity Design and Performance of Call Admission Control in Cellular CDMA Systems , 1997, IEEE J. Sel. Areas Commun..

[4]  Yasushi Yamao,et al.  Capacity improvement with a multihop access scheme in broadband CDMA cellular systems , 2003 .

[5]  Laurence B. Milstein,et al.  On the Feasibility of a CDMA Overlay for Personal Communications Networks , 1992, IEEE J. Sel. Areas Commun..

[6]  Rahim Tafazolli,et al.  On the relaying capability of next-generation GSM cellular networks , 2001, IEEE Wirel. Commun..

[7]  Chunming Qiao,et al.  Integrated cellular and ad hoc relaying systems: iCAR , 2001, IEEE J. Sel. Areas Commun..

[8]  Steve McLaughlin,et al.  Capacity and power investigation of opportunity driven multiple access (ODMA) networks in TDD-CDMA based systems , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[9]  Andrea J. Goldsmith,et al.  Capacity regions for wireless ad hoc networks , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[10]  Andrew J. Viterbi,et al.  Erlang Capacity of a Power Controlled CDMA System , 1993, IEEE J. Sel. Areas Commun..