CDMA多工技術確實能有效提昇無線通訊的使用效能。不過特徵碼的非正交性與通道的頻率選擇效應，將使CDMA系統效能受限於多使用者存取干擾的影響，而降低通訊服務品質，多使者偵測器已被證實是其中一種有效克服多使用者存取干擾的方法。因此，本論文嘗試以不同的決策結果，建構不同的偵測輔助機制，來發展在不同CDMA系統下，低複雜度、高效能的多使用者偵測器。
本論文第一個論述在單輸入單輸出的CDMA系統下，發展一種決策輔助的結合式最小均方差/串列干擾消除的多使用者偵測器。在降低運算複雜度的考量下，先將傳送訊號強度相接近者視為同群來作分群，並依傳送訊號強度順序，以最小均方差多使用者偵測器與串列干擾消除器作初步偵測，而後透過這初步偵測結果的協助，進一步降低第二次偵測時的干擾影響，以提昇最後的偵測效能。
本論文第二個論述是在單輸入多輸出的多路徑CDMA系統下，發展兩種軟式決策資訊輔助的反覆式時-空多使用者偵測器。首先，我們將原本的時-空使用者偵測器拆解成兩個秩數都為1的時域使用者偵測器和空域使用者偵測器，以便降低運算複雜度。接著為了提昇偵測效能，我們將其中一個偵測器的軟式決策輸出，作為協助另一個偵測器來強化其偵測的資訊或提昇干擾的估測能力，然後以此方式，交替地修正這兩個使用者偵測器，進而提昇偵測的品質。
本論文第三個論述是在群組式的多輸入多輸出CDMA系統下，發展一種部份軟式決策資訊輔助的串列式多使用者偵測器。首先，採用群組偵測方式以降低運算複雜度，並以相同特徵碼的傳送訊號視為相同群組並一起作偵測、訊號回建與移除，而這移除機制將是降低訊號維度的動作。如此，可得到低複雜度的好處，不過也會產生錯誤傳遞效應。因此，我們進一步以軟式決策資訊作為提昇效能的方式，不過為避免系統的複雜度加高過多，這決策資訊只有部份資訊被回授來輔助偵測。
本論文第四個論述是高速傳輸的多輸入多輸出MC-CDMA系統下，發展一種兩級式異質決策資訊輔助的多使用者偵測器。這群組式的多輸入多輸出MC-CDMA系統將考慮在多細胞無線通訊環境下，多種不同干擾同時存在。其中，有未知的特徵碼所傳送的訊號干擾，因此，我們採用線性限制最小變異法則。由於第一級所產生的硬式決策和第二級串列群組的軟式決策資訊的同時輔助下，將使干擾的估測不會因群組增加的結果而使系統效能惡化，進而改善偵測品質。
此外，我們也對上述各個論述，進行計算機模擬與效能分析，結果也驗証了我們所提的多使用者偵測器確實能夠提供低複雜度、高效能的偵測品質。

In this thesis, we propose several effective, yet low complexity multiuser detectors (MUDs) under various CDMA systems. The investigation of this thesis includes the followings. First, a decision aided hybrid of minimum mean-squared error (MMSE) MUD and successive interference cancellation (SIC) is addressed for single-input single-output (SISO) CDMA systems. The proposed MUD first divides the users into groups, with each group consisting of users with a close power level. The SIC is then employed to distinguish users among different groups, while the MMSE MUD is invoked to detect users within each group. As such, the high computational overhead of the MMSE MUD and the latency
problem in the SIC can then be substantially alleviated.

Second, two soft information assisted space-time MUDs are addressed for multipath CDMA systems. The space-time MUD considered is of rank one and decoupled into a product of spatial filter and temporal filter. The soft information is then appropriately exchanged in the alternative updating of either the spatial filter or temporal filter.

Third, a layered group space-time MUD with the assistance of partial soft information (PSI) is presented for multiple input multiple output (MIMO) CDMA systems. First, to avoid the annoying ordering problem, the channel strength is employed to order the groups. Thereafter, a group MMSE-based detection is addressed to sequentially detect multiple layers of each group in parallel,
wherein the PSI, fed back from the previous group, is utilized to assist the detection of the signals in the present group.

Finally, we address an effective semiblind group MUD with the assistance of heterogenous information for MIMO multi-carrier CDMA (MC-CDMA) systems. The MUD considered consists of two stages of linear constrained minimum variance (LCMV) detectors. At the first stage of the first MUD, based on the LCMV metric, a tentative (hard) estimation of the transmitted symbols are conducted in parallel and then forwarded to the next stage for refined interference estimation. A heterogenous information approach is then adopted at the second stage of the LCMV MUD to refine the estimation of the interferences group by group. The symbols are then detected based on a set of soft LCMV detectors.

Conducted simulations results show that the developed MUDs can offer significant performance gain compared with previous works in various scenarios, especially when the hardware cost is at a premium. The comparison of computational overhead is also made to justify the validity of these MUDs.

[1] M. P. Metroka, “An introduction to narrowband AMPS,” Proc. IEEE Globe-
Com, vol. 2, pp. 1463-1468, Dec. 1991.
[2] J. Uddenfeldt, “Digital cellular-its roots and its future,” Proc. of IEEE, vol.86, pp. 1319-1324, July 1998.
[3] J. Uddenfeldt, “GSM-European cellular goes digital,” IEE Review, vol.37, pp.253-257, July 1991.
[4] V. K. Garg, IS-95 and CDMA2000. Prentice Hall, Upper Saddle River, NJ,
2000.
[5] T. Ojanpera and R. Prasad, “An overview of third-generation wireless personal communications: a European prospective,” Wireless Pers. Commun.,
vol. 5, no. 6, pp. 59-65, Dec 1998.
[6] M. W. Oliphant, “Third-generation wireless must wait for services to catch
up,” IEEE Spectrum, vol. 39, pp. 14-16, June 2002.
[7] H. Zhai, X. Chen, Y. Fang, “How well can the IEEE 802.11 wireless LAN
support quality of service?,” IEEE Trans. Wireless Commun., vol. 4, pp.
3084-3094, Nov. 2005.
[8] C. Huang, H.-H. Juan, M.-S. Lin, and C.-J. Chang, “Radio resource management of heterogeneous services in mobile WiMAX systems,” IEEE Wireless
Commun., vol. 14, pp. 20-26, Feb. 2007.
[9] L. C. Godara, “Applications of antenna arrays to mobile communications, part I: Performance improvement, feasibility, and system considerations,”Proc. of IEEE., vol. 85, pp. 1031-1060, July 1997.
[10] L. C. Godara, “Applications of antenna arrays to mobile communications,
part II: Beamforming and direction-of-arrival considerations,” Proc. of IEEE.,
vol. 85, pp. 1195-11245, Aug 1997.
[11] K. Sheikh, D. Gesbert, D. Gore and A. Paulraj, “Smart antenna for broadband wireless access networks,” IEEE Pers. Commun., vol. 37, pp. 100-105,
Nov. 1999.
[12] S. Verdu, Multiuser Detection. Cambridge University Press, 1998.
[13] S. Moshavi, “Multi-user detection for DS-CDMA communications,” IEEE
Commun. Mag., pp.124-136, Oct. 1996.
[14] S. Alamouti, “A simple transmit diversity scheme for wireless communications,”
IEEE J. Select. Areas Commun., vol. 17, pp. 1451-1458, Oct. 1998.
[15] V. Tarokh, H. Jafarkhani and A. R. Calderbank, “Space-time block codes from orthogonal designs,” IEEE J. Select. Areas Commun., vol. 45, pp. 1456-1467, July 1999.
[16] G. J. Foschini, G. D. Golden, R. A. Valenzuela, and P. W. Wolniansky, “Simplified processing for high spectral efficiency wireless communications employing multi-element arrays,” IEEE J. Select. Areas Commun., vol. 17, pp.
1841-1852, Nov. 1999.
[17] C. Berrou and A. Glavieux, “Near optimum error correcting coding and decoding: Turbo codes,” IEEE Trans. Commun., vol. 44, pp. 1261-1271, Oct.
1996.
[18] R. Koetter, A. C. Singer, and M. Tiiuchler, “Turbo equalization,” IEEE Signal Processing Mag., vol. 21, pp. 67-80, Jan. 2004.
[19] X. Wang and H. V. Poor, “Iterative (turbo) soft interference cancellation and decoding for coded CDMA,” IEEE Trans. Commun., vol. 47, pp. 1046-1061, July 1999.
[20] G. S. Rajappan and M. L. Honig, “Signature sequence adaptation for DSCDMA
with multipath,” IEEE J. Select. Areas Commun., vol. 20, pp. 384-395, Feb. 2002.
[21] S. Ulukus and R. Yates, “Iterative construction of optimum signature sequence sets in synchronous CDMA systems,” IEEE Trans. Inform. Theory, vol. 47, pp. 1989-1998, July 2001.
[22] S. Serbetli and A. Yener, “MIMO-CDMA systems: Signature and beamformer
design with various levels of feedback,” IEEE Trans. Signal Process., vol. 54,
pp. 2758-2772, July 2006.
[23] J. H. Deng and T. S. Lee, “An iterative maximum SINR receiver for multicarrier CDMA system over a multipath fading channel with frequency offset,”IEEE Trans. Wireless Commun., vol.2, pp. 560-569, May. 2003.
[24] P. Lupas and S. Verdu, “Linear multiuser detectors for synchronous codedivision multiple-access channels,” IEEE Trans. Inform. Theory, vol.35, pp. 123-136, Jan. 1989.
[25] A. Yener, R. D. Yates, and S. Ulukus, “Interference management for CDMA
systems through power control, multiuser detection and beamforming,” IEEE
Trans. Commun., vol. 49, pp. 1227-1239, July 2001.
[26] M. K. Varanasi, “Decision feedback multiuser detection: a systematic approach,”IEEE Trans. Infom. Theory, vol. 45, pp. 219-240, Jan. 1999.
[27] C.-C Hsu and Y. Lee, “Multi-stage MMSE weighted decision feedback multiuser detection for DS-CDMA and MC-CDMA,” in Proc. IEEE VTC, pp.
2421-2425, 2004.
[28] M. L. Honig and G. K. Woodward, and Y. Sun, “Adaptive iterative multiuser
decision feedback detection,” IEEE Trans. Wireless Commun., vol. 3, pp.
477-485, Mar. 2004.
[29] R. Steele, Mobile Radio Communicaitons. Pentech Press, London, 1992.
[30] T. S. Rappaport, Wireless Communications: Principles and Practice. Upper
Saddle River, NJ: Prentice Hall, 2nd 2002.
[31] S. M. Redl, M. K. Weber, and M. W. Oliphant, GSM and Personal Communications Handbook. Artech House, Norwood, MA, 1998.
[32] B. Bing, R. Van Nee, and V. Hayes, Wireless local area and home networks
.IEEE Commun. Mag., vol. 39, pp. 63-157, Nov. 2001.
[33] G.-C. Yang, “Asynchronous fast frequency-hopping CDMA cellular systems,”
IEEE Trans. Veh. Technol., vol. 45, pp. 676-682, Nov. 1996.
[34] M. Chen, “An upper bound on the convergence rate of uplink power control in DS-CDMA systems,” IEEE Commun. Lett., vol. 10, pp. 231-233, Apr. 2006.
[35] S. Hara and R. Prasad, “An overview of multicarrier CDMA,” IEEE Commun.
Mag., vol. 35, pp. 126-133, Dec. 1997.
[36] L. Hanzo, M. M¨unster, B. J. Choi, and T. Keller, OFDM and MC-CDMA.
John Wiley and IEEE Press, 2003.
[37] Y. Sun, “Bandwidth-efficient wireless OFDM,” IEEE J. Select. Areas Commun., vol. 19, pp. 2267-2278, Nov. 2001.
[38] H. Yang, “A road to future broadband wireless access: MIMO-OFDM-Based
air interface,” IEEE Commun. Mag., vol. 43, pp. 53-60, Jan. 2005.
[39] U. Ladebusch and C. A. Liss, “Terrestrial DVB (DVB-T): a broadcast technology for stationary portable and mobile use,” Proc. of IEEE., vol. 94, pp. 183-193, Jan. 2006.
[40] J. G. Proakis, Digital Communications. 4th ed., McGraw-Hill, 2001.
123
[41] R. Kohno, H. Imai, M. Hatori, and S. Pasupathy, “Combination of an adaptive array antenna and a canceller of interference for direct-sequence spreadspectrum multiple-access system,” IEEE J. Select. Areas Commun., vol. 8,
pp. 641-649, May 1990.
[42] X. Bernstein and A. M. Haimovic, “Space-time processing for incrreased capacity of wireless CDMA,” in Proc. IEEE Int. Conf. Commun. Sys., pp.
597-601, 1996.
[43] G. J. Foschini and M. J. Gans, “On limits of wireless communications in a
fading environment when using multiple antennas,” Wireless Pers. Commun.,
vol. 6, no. 3, pp. 311-335, Mar. 1998.
[44] I. E. Telatar, “Capacity of multiantnna Guassian channels,” European Trans. Tel., vol. 10, pp. 585-595, Nov./Dec. 1999.
[45] A. Yener and R. D. Yates, and S. Ulukus, “Combined multiuser detection
and beamforming for CDMA systems: Filter structures,” IEEE Trans. Veh.
Technol., vol. 51, pp. 1087-1095, Sep. 2002.
[46] G. Golden, G. Foschini, R. Valenzuela, and P. Wolniansky, “Detection algorithm and initial laboratory results using V-BLAST space-time communication
architecture,” Elec. Lett., vol. 35, pp. 14-16, Jan. 1999.
[47] L.-U. C. Ruly, R. D. Murch, and K. B. Letaief, “MIMO CDMA antenna
system for SINR enhancement,” IEEE Trans. Wireless Commun., vol. 2, pp.
240-249, Mar. 2003.
[48] C. Wan, J. G. Andrews, and R. W. Heath, Jr., “Antenna partitioning for
multiuser MIMO-CDMA,” Proc. IEEE GlobeCom, vol. 3, pp. 1535-1539, Dec.
2005.
[49] M. Y. Alias, S. Chen, and L. Hanzo, “Multiple-antenna aided OFDM employing genetic-algorithm-assisted minimum bit error rate multiuser detection,”IEEE Trans. Veh. Technol., vol. 54, pp. 1713-1721, Sep. 2005.
[50] A. Paulraj, R. Nabar, and D. Gore, Introduction to Space-Time Wireless
Communications. Cambridge University press 2003.
[51] A. F. Molisch and M. Z. Win, “MIMO systems with antenna selection,” IEEE
Micro. Mag., vol. 5, pp. 46-56, Mar. 2004.
[52] H. Chen, H. Alexander, and S. A. Jon, “Turbo space-time codes with time
varying linear transformations,” IEEE Trans. Commun., vol. 6, pp. 486-493,
Feb. 2007. [53] G. Ping and C. Tepedelenlioglu, “Space-time coding over fading channels with impulsive noise,” IEEE Trans. Wireless Commun., vol. 6, pp. 220-229, Jan. 2007.
[54] T. Niyomsataya, A. Miri, and M. Nevins, “A new unitary space-time code
with high diversity product,” IEEE Trans. Wireless Commun., vol. 5, pp.
3045-3049, Nov. 2006.
[55] H. V. Poor, “Itervative multiuser detection,” IEEE Trans. Signal Processing Mag., vol. 21, pp. 81-88, Jan. 2000.
[56] Z. Li and M. Latva-Aho, “Nonblind and semiblind space-frequency multiuser
detection for multirate MC-CDMA systems,” IEEE Trans. Signal Processing.,
vol. 54, pp. 4393-4404, Nov. 2006.
[57] A. Kapur and M. K. Varanasi, “Multiuser detection for overloaded CDMA
systems,” IEEE Trans. Inform. Theory, vol. 49, pp. 1728-1742, July 2003.
[58] S. Verdu, “Minimum probability of error for asynchronous Gaussian multipleaccess channels,” IEEE Trans. inform. Theory, vol. IT-32, pp. 85-96, Jan. 1986.
[59] L. Yang and K. Kwak, “Blind adaptive decorrelative multiuser detector for
CDMA systems with m-ary nonlinear modulation,” in Proc. IEEE Personal,
Indoor, and Mobile Radio Commun., pp. 2135-2138, 2003.
[60] S. Buzzi, M. Lops, and A. M. Tulino, “A new family of MMSE multiuser
receivers for interference suppression in DS/CDMA systems employing BPSK
modulation,” IEEE Trans. Wireless Commun., vol 49, pp. 154-167, Jan. 2001.
[61] K.-C. Lai and J. J. Shynk, “Performance evaluation of a generalized linear SIC for DS/CDMA signals,” IEEE Trans. Signal Processing, vol. 51, pp. 1604- 1614, June 2003.
[62] Y. D. Li and T. T. Tjhung, “Performance analysis of PIC-CDMA systems,”
in Proc. IEEE Int. Conf. Commun. Sys., pp. 1086-1090, 2002.
[63] P. Patel and J. Holtzman, “Performance comparison of a DS/CDMA system
using a successive interference cancellation (IC) scheme and a parallel IC
scheme under fading,” in Proc. IEEE ICC, pp. 510-514, 1994.
[64] A. Host-Madsen and K.-S. Cho, “MMSE/PIC multiuser detection for
DS/CDMA systems with inter- and intra-cell interference,” IEEE Trans.
Commun., vol. 47, pp. 291-299, Feb. 1999.
[65] A. Duel-Hallen, “A family of decision feedback multiuser detectors for asynchronous code-division multiple-access channels,” IEEE Trans. Commun.,
vol. 43, pp. 421-434, 1995.
[66] D. Koulakiotis and A. H. Aghvami, “Evaluation of a DS/CDMA multiuser
receiver employing a hybrid form of interference cancellation in Rayleighfading
channels,” IEEE Commun. Lett., vol. 2, pp. 61-63, Mar. 1998.
[67] N. Kim and M. K. Howlader, “Analysis of a new hybrid interference cancellation (HIC) system,” in Proc. IEEE WCNC, pp. 1828-1832, 2004.
[68] A. Kong and C. Wan, “A novel blind space-time multiuser detector for DSCDMA system,” IEEE Commun. Lett., vol. 10, pp. 177-179, Mar. 2006.
[69] G. J. Foschini, G. D. Golden, R. A. Valenzuela, and P.W. Wolniansky, “Simplified processing for high spectral efficiency wireless communications employing multi-element arrays,” IEEE J. Select. Areas Commun., vol. 17, pp.
1841-1852, Nov. 1999.
[70] C. B. Papadias and H. Huang, “Linear space-time multiuser detection for
multipath CDMA channels,” IEEE J. Select. Areas Commun., vol. 19, pp.
254-265, Feb. 2001.
[71] H. Lei and F.-C. Zheng, “Space-time blind multiuser detection for multirate DS/CDMA signals,” IEEE Trans. Veh. Technol., vol. 53, pp. 1746-1755, Nov. 2004.
[72] Z. Ying and Z. Junli, “Multiuser detection employing particle swarm optimization in space-time CDMA systems,” in Proc. IEEE ISCIT, vol. 2, pp.
972-974, Oct. 2005.
[73] X. Wang and H. V. Poor, “Space-time multiuser detection in multipath
CDMA channels,” IEEE Trans. Signal Processing., vol. 47, pp. 2356-2374,
Sep. 1999.
[74] ¨O. Filiz and A. Yener, “Rank constrained temporal-spatial matrix filters for CDMA systems,” IEEE Trans. Wire. Commun., vol. 3, pp. 1974-1979, Nov. 2004.
[75] P. Rao and V. K. Prabhu, “A successive interference cancellation multiuser detector for MIMO CDMA systems,” in Proc. IEEE VTC, pp. 1075-1079,
2003.
[76] S. Sfar, R. D. Murch, and K. B. Letaief, “Layered space-time multiuser detection over wireless uplink systems,” IEEE Trans. Wire. Commun., vol. 2,
pp. 653-668, July 2003.
[77] S. Sfar and K. B. Letaief, “Layered group detection for multiuser mimo wireless cdma systems,” IEEE Trans. Wire. Commun., vol. 5, pp. 2305-2311, Sep.
2006.
[78] X. Wang and A. Host-Madsen, “Group-blind multiuser detection for uplink
CDMA,” IEEE J. Select. Areas Commun., vol. 17, pp. 1841-1852, Nov. 1999.
[79] G.Woodward, R, Ratasuk, M. L. Honig, and P. B. Rapajic, “Minimum meansquared error multiuser decision-feedback detectors for DS-CDMA,” IEEE
Trans. Commun., vol. 50, pp. 2104-2112, Dec. 2002.
[80] G. J. M. Janssen and S. B. Slimane, “Antenna diversity for a narrow-band
successive-cancellation multiuser detector,” IEEE Trans. Veh. Technol., vol.
53, pp. 1303-1315, Sep. 2004.
[81] P. D. Alexander and M. C. Reed, “Iterative multiuser interference reduction: turbo CDMA,” IEEE Trans. Commun., vol. 47, pp. 1008-1014, July. 1999.
[82] A. D. Damnjanovic and B. R. Vojcic, “Iterative multiuser detection/decoding for turbo coded CDMA systems,” IEEE Commun. Lett., vol. 5, pp. 104-106, Mar. 2001.
[83] C.-H. Tsai, W.-H. Fang and J.-T. Chen, “Hybrid MMSE and SIC for multiuser
detection,” in Proc. IEEE VTC, pp. 1779-1783, 2001.
[84] H.-Y. Lu, W.-H. Fang and W.-S. Yang, “Decision aided MMSE/SIC multiuser
detection for DS/CDMA systems,” in Proc. IEEE 6th CAS Symp. on
Emerging Tech.: Mobile and Wireless Comm., pp. 795-798, 2004.
[85] S. Verdu, Optimum multiuser asymptotic efficiency,” IEEE Trans. Commun.,
vol. com-34, pp. 890-897, Sep. 1986.
[86] X. Wang and H. V. Poor, “Blind multiuser detection: A subspace approach,”IEEE Trans. Inform. Theory, vol. 44, pp. 677-690, Mar. 1998.
[87] G. B. Gianakis et al., ed., Signal Processing Advances in Wireless and Mobile Communicatins. vol. 1, Trends in Channel Estimation and Equalization.
Prentice Hall, Upper Saddle River, NJ, 2000.
[88] H. Harada and R. Prasad, Simulation and Software Radio for Mobile Communications. Artech House, Boston Londo, 2002.
[89] G. H. Golub and C. F. Van Loan, Matrix Computations. 3rd ed. Johns Hopkins
University Press, 1996
[90] X. Wang and H. V. Poor,Wireless Communication Systems. Pearson Edu.,
Inc., NJ, 2004.
[91] M. Zorzi, J. Zeidler, A. Anderson, B. Rao, J. Proakis, A. L. Swindlehurst, M. Jensen, and S. Krishnamurthy, “Cross-layer issues in MAC protocol design for MIMO ad hoc networks,” IEEE Trans. Wireless Commun., vol. 13, pp. 62-76, Aug. 2006.
[92] B. Chen and M. J. Gans, “MIMO communications in ad hoc networks,” IEEE
Trans. Singal Processing, vol. 54, pp. 2773-2783, July 2006.
[93] C. Liang, and K. R. Dandekar, “Power management in MIMO ad hoc networks:
A game-theoretic approach ,” IEEE Trans. Wireless Commun., vol.
6, pp. 1164-1170, Apr. 2007.
[94] P. L. Kafle and A. B. Sesay, “Iterative semi-blind multiuser detection for coded MC-CDMA uplink system,” IEEE Trans. Commun., vol. 51, pp. 1034-1039,
2003.
[95] H.-Y. Lu and W.-H. Fang, “Soft information assisted space-time multiuser
detection for multipath CDMA,” in Proc. IEEE WCNC, pp. 917-921, Mar.,
2007.
[96] J.-Y. Chung, W.-H. Fang, and H.-Y. Lu, “Layered space-time MUD with
adaptive group order successive interference cancellation,” in Proc. IEEE Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, pp. 1162-1165, Beijing, China, Aug., 2005.
[97] M. K. Varanasi, “Group detection for synchronous Gaussian code-division
multiple-access channels,” IEEE Trans. Inform. Theory., vol. 4, pp. 1083-
1095, July 1995.
[98] H. V. Poor and S. Verdu, “Probability of error in MMSE multiuser detection,”IEEE Trans. Inform. Theory, vol. 43, pp. 858-871, May 1997.
[99] T. K. Moon and W. C. Stirling, Mathematical Method and Algorithms for
Signal Processing. Prentice Hall, 2000.
[100] J. Wang and C. Zhao, “A semi-blind detection algorithm for V-BLAST system,”in Proc. IEEE GlobeCom, pp. 3366-3370, 2003.
[101] Z. Mao and V. K. Bhagava, “Semiblind linear parallel interfrence cancellation multiuser detectors for DS-CDMA systems,” IEEE Trans. Wireless
Commun., vol. 4, pp. 1319-1324, July 2005.
[102] G. Zhang, G. Bi, and L. Zhang, “Group-blind intersymbol multiuser detection for downlink CDMA with multipath,” IEEE Trans. Wireless Commun.,
vol. 4, pp. 434-443, Mar., 2005.
[103] R. W. Heath Jr., and A. J. Paulraj, “Switching between spatial multiplexing and transmit diversity based on constellation distance,” in Proc. Allerton Conf. on Commun., Control, and Computing, Oct. 2000.
[104] D. Gesbert, L. Haumonte, H. Bolcskei, R. Krishnamoorthy, and A, J.
Paulraj,“Technologies and performance for non-line-of-sight broadband wireless access network,” IEEE Commun. Mag., vol. 40, pp. 86-95, Apr 2002.