Uplink user capacity in a multicell CDMA system with hotspot microcells

The number of simultaneous users (or user capacity) supportable on the uplink of a multiple-macrocell code division multiple-access (CDMA) system with multiple "hotspot" microcells embedded within is studied. These microcells operate on the same frequency as the macrocells and are installed in regions of high user demand. It is shown that the user capacity depends on how the users are distributed among cells, and that the maximum (called the attainable capacity) occurs when all cells serve roughly the same number of users. The approach builds on a two-cell analysis published previously, for a single microcell embedded in a single macrocell. First, this analysis is expanded upon to estimate the attainable capacity for M macrocells, where the center one contains L microcells. Then the case in which L microcells are distributed randomly among the M macrocells is analyzed. In each case, the formula for attainable capacity is very simple and highly accurate (as demonstrated via simulations) up to reasonably high values of L. For example, with L microcells distributed among M macrocells, the analysis is accurate at least up to eight microcells per macrocell. The analysis and results are general with respect to cell geometries, propagation parameters, and other variables of the two-tier CDMA system

[1]  Dong Hee Kim,et al.  Other-cell interference with power control in macro/microcell CDMA networks , 1996, Proceedings of Vehicular Technology Conference - VTC.

[2]  H. Vincent Poor,et al.  Capacity in a CDMA macrocell with a hotspot microcell: exact and approximate analyses , 2001, IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211).

[3]  D. Luenberger.  Optimization by Vector Space Methods , 1968 .

[4]  H. Vincent Poor,et al.  Downlink user capacity in a CDMA macrocell with a hotspot microcell , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[5]  Yvo L. C. de Jong,et al.  A building-transmission model for improved propagation prediction in urban microcells , 2004, IEEE Transactions on Vehicular Technology.

[6]  Marko E. Leinonen,et al.  Performance of a CDMA based hierarchical cell structure network , 1997, Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97.

[7]  H. Vincent Poor,et al.  Uplink user capacity of a multi-cell CDMA system with hotspot microcells , 2002, Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367).

[8]  L.J. Greenstein,et al.  An empirically-based path loss model for wireless channels in suburban environments , 1998, IEEE GLOBECOM 1998 (Cat. NO. 98CH36250).

[9]  R. S. Karlsson.  Radio resource sharing and capacity of some multiple access methods in hierarchical cell structures , 1999, Gateway to 21st Century Communications Village. VTC 1999-Fall. IEEE VTS 50th Vehicular Technology Conference (Cat. No.99CH36324).

[10]  Andrew J. Viterbi,et al.  On the capacity of a cellular CDMA system , 1991 .

[11]  J.-S. Wu,et al.  Analysis of uplink and downlink capacities for two-tier cellular system , 1997 .

[12]  H. Vincent Poor,et al.  Uplink user capacity in a CDMA system with hotspot microcells: effects of finite transmit power and dispersion , 2006, IEEE Transactions on Wireless Communications.

[13]  Jung-Shyr Wu,et al.  Performance study for a microcell hot spot embedded in CDMA macrocell systems , 1999 .

[14]  L.J. Greenstein,et al.  A microcell/macrocell cellular architecture for low- and high-mobility wireless users , 1991, IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record.

[15]  H. Vincent Poor,et al.  Uplink user capacity in a CDMA macrocell with a hotspot microcell: exact and approximate analyses , 2003, IEEE Trans. Wirel. Commun..

[16]  Yvo L. C. de Jong,et al.  A tree-scattering model for improved propagation prediction in urban microcells , 2004, IEEE Transactions on Vehicular Technology.

[17]  J.J. Gaytan,et al.  Analysis of capacity gain and BER performance for CDMA systems with desensitized embedded microcells , 1998, ICUPC '98. IEEE 1998 International Conference on Universal Personal Communications. Conference Proceedings (Cat. No.98TH8384).

[18]  D. Lara-Rodriguez,et al.  Performance of a new microcell/macrocell cellular architecture with CDMA access , 2000, VTC2000-Spring. 2000 IEEE 51st Vehicular Technology Conference Proceedings (Cat. No.00CH37026).

[19]  J. Shapira.  Microcell engineering in CDMA cellular networks , 1994 .

[20]  H. Vincent Poor,et al.  User capacity in a CDMA macrocell with a hotspot microcell: effects of transmit power constraints and finite dispersion , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[21]  Dong Hee Kim,et al.  Capacity analysis of macro/microcellular CDMA with power ratio control and tilted antenna , 2000, IEEE Trans. Veh. Technol..