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(12) United States Patent (10) Patent No.: US 8,521,103 B2 Zhang Et Al

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(12) United States Patent (10) Patent No.: US 8,521,103 B2 Zhang Et Al USOO8521 1 03B2 (12) United States Patent (10) Patent No.: US 8,521,103 B2 Zhang et al. (45) Date of Patent: *Aug. 27, 2013 (54) METHOD AND SYSTEM FOR A GREEDY (56) References Cited USER GROUP SELECTION WITH RANGE REDUCTION IN TOD MULTUSER MMO U.S. PATENT DOCUMENTS DOWNLINK TRANSMISSION 6,052,596 A 4/2000 Barnickel 6,131,031 A 10/2000 Lober et al. (75) Inventors: Chengjin Zhang, La Jolla, CA (US); 6,728.307 B1 4/2004 Derryberry et al. Jun Zheng, La Jolla, CA (US); Pieter (Continued) van Rooyen, San Diego, CA (US) FOREIGN PATENT DOCUMENTS (73) Assignee: Broadcom Corporation, Irvine, CA CN 1574685 A 2, 2005 (US) EP 1265389 A2 12/2002 EP 1505741 A2 2, 2005 (*) Notice: Subject to any disclaimer, the term of this WO WO 2005/06O123 A1 6/2005 past list: sited under 35 OTHER PUBLICATIONS is- Behrouz. Farhang-Boroujeny et al., “Layering Techniques for Space spent is Subject to a terminal dis Time Communication in Multi-User Networks.” Proceedings of the IEEE Vehicular Technology Conference, vol. 2, pp. 1339-1343, IEEE (21) Appl. No.: 13/534,492 (2003). Continued (22) Filed: Jun. 27, 2012 ( ) (65) Prior Publication Data Primary Examiner — Tuan H Nguyen US 2012/O269104A1 Oct. 25, 2012 (74) Attorney, Agent, or Firm — Sterne, Kessler, Goldstein • 1-a-s & Fox PL.L.C. Related U.S. Application Data (63) Continuation of application No. 13/074,692, filed on (57) ABSTRACT continuationMar. 29, 2011, of applicationnow Pat. No. No. 8,233,848, 1 1/231.701, which filed is on a CertaiCertain aspects off a methodhod and system ffor processing signalsignal Sep. 21, 2005 pp. t. No. 7 9 17,101 s s in a communication system may include maximizing system ep. Zl, , now Fal. No. 1.91 / 1 UI. capacity for a communication system, based on a signal for a (51) Int. Cl user within a search range and at least one other signal for one ioC 7/02 (2006.01) other user within the search range. The search range may be H04B I/02 (200 6,015 generated by sorting a plurality of signals based on a channel H04B 7/02 (2006.015 gain corresponding to each of the plurality of signals. The (52) U.S. Cl signal for the user may be selected from the search range AV e. we corresponding to a channel gain that is greater than a channel USPC - - - - - - - - - - - grgr. 455/101; 455/62:455/69 gain corresponding to a remaining portion of the search (58) Field of Classification Search range. USPC ............ 455/62, 69, 67.11, 101, 115.3, 166.2, 455/509, 513 See application file for complete search history. 20 Claims, 7 Drawing Sheets cost f sciet W After K. 45: 184 53 aw- Signs intended for user 1 Signatnisked fur userk UpakEsias Channai Presser Mermay US 8,521,103 B2 Page 2 (56) References Cited Knopp, Robert and Humblet, P.A., “Information Capacity and Power Control in Single-Cell Multiuser Communications.” International U.S. PATENT DOCUMENTS Conference on Communications vol. 1, pp. 331-335, IEEE (1995). 6,898,250 B2 5, 2005 Lee et al. Lau, Vincentet al., “On the Design of MIMO Block-Fading Channels 7,110,378 B2 9/2006 Onggosanusi et al. with Feedback-Link Capacity Constraint.” IEEE Transactions. On 7,120,395 B2 10/2006 Tong et al. Communications, vol. 52, No. 1, pp. 62-70 (Jan. 2004). 7,139,328 B2 11/2006 Thomas et al. 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Access (SDMA) With Scheduling.” IEEE Transactions on Wireless Gesbert, David and Alouini, Mohamed-Slim, "How Much Feedback Communications, vol. 1, No. 4, IEEE (Oct. 2002). Is Multi-User Diversity Really Worth?” Proceedings of the IEEE Yoo, Taesang and Goldsmith, Andrea, "Optimality of Zero-Forcing international. Conference on Communications and Networking Con Beamforming with Multiuser Diversity.” IEEE International Confer ference, vol. 1, pp. 234-238, IEEE (2004). ence on Communications, 5 pages, IEEE (2005). Heath, Robert W. et al., “Multiuser Diversity for MIMO Wireless International Search Report for International Application No. EP 1 Systems with Linear Receivers.” The 35" Asilornar Conference on 768 274, European Patent Office, Germany, completed on Mar. 18. Signals, Systems and Computers, vol. 2, pp. 1194-1199, IEEE 2011. (2001). International Search Report for International Application No. EP 1 Hochwald, Bertrand M. et al., “A Vector-Perturbation Technique for 768 275, European Patent Office, Germany, completed on Apr. 4. Near-Capacity Multiantenna Multiuser Communication—Part 2: 2011. Perturbation.” IEEE Transactions on Communications, vol. 53, No. 3, pp. 537-544 (Mar. 2005). * cited by examiner U.S. Patent Aug. 27, 2013 Sheet 1 of 7 US 8,521,103 B2 1=caºaese --~~~~--~~~~ s U.S. Patent Aug. 27, 2013 Sheet 2 of 7 US 8,521,103 B2 } & „--------·······----------------------~--~~~~~~~~•••••••••••~~~~~~~~); U.S. Patent Aug. 27, 2013 Sheet 4 of 7 US 8,521,103 B2 252 Y.wy wamaam Max Chan?ei measurement {h(t)} , t = 1,....T - Search for optimal users S D.,..(t) t) = ararg D-1.TIDs7, MPCr?t ) t = 1,..., T R Swar-r -- 256 v. V 3 CDF of optimat user index A.
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