USOO765O152B2
`
`(12) United States Patent
`Li et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,650,152 B2
`*Jan. 19, 2010
`
`(54) MULTI-CARRIER COMMUNICATIONS WITH
`ADAPTIVE CLUSTER CONFIGURATION
`AND SWITCHING
`
`(75)
`
`(73)
`(*)
`
`(21)
`(22)
`(65)
`
`(63)
`
`Inventors: Xiaodong Li, Bellevue, WA (US); Hui
`Liu, Clyde Hill, WA (US); Wenzhong
`Zhang, Bellevue, WA (US); Kemin Li,
`Bellevue, WA (US)
`Assignee: Adaptix, Inc., Carrollton, TX (US)
`Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`This patent is Subject to a terminal dis
`claimer.
`
`Appl. No.: 11/931,385
`
`Filed:
`
`Oct. 31, 2007
`
`Prior Publication Data
`US 2008/0219363 A1
`Sep. 11, 2008
`
`Related U.S. Application Data
`Continuation of application No. 1 1/592,084, filed on
`Nov. 2, 2006, now Pat. No. 7,379,742, which is a
`continuation of application No. 09/837,701, filed on
`Apr. 17, 2001, now Pat. No. 7,146,172, which is a
`continuation-in-part of application No. 09/738,086,
`filed on Dec. 15, 2000, now Pat. No. 6,947,748.
`
`(51)
`
`(52)
`
`Int. C.
`(2006.01)
`H04O 7/20
`U.S. Cl. .................... 455/452.1; 455/447; 455/450;
`455/452.2:455/453; 370/343; 370/347; 375/276
`
`(58) Field of Classification Search .............. 455/452.1,
`455/447, 450, 452.2, 453; 370/343, 347;
`375/276
`See application file for complete search history.
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`
`4,355,411 A
`4,670,889 A
`5,038,399 A
`5,239,676 A *
`
`10, 1982
`Reudink et al.
`6, 1987
`Hewitt et al.
`8, 1991
`Bruckert
`Strawczynski et al. ...... 455,437
`8, 1993
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`CN
`
`1245623
`2, 2000
`(Continued)
`OTHER PUBLICATIONS
`Bender et al., CDMA/HDR: A Bandwidth-Efficient High-Speed
`Wireless Data Service for Nomadic Users, IEEE Communications
`Magazine, Jul. 2000, pp. 70-87
`(Continued)
`Primary Examiner Stephen M D'Agosta
`(74) Attorney, Agent, or Firm—Fullbright & Jaworski, L.L.P.
`
`(57)
`ABSTRACT
`A method and apparatus for allocating Subcarriers in an
`orthogonal frequency division multiple access (OFDMA)
`system is described. In one embodiment, the method com
`prises allocating at least one diversity cluster of subcarriers to
`a first Subscriber and allocating at least one coherence cluster
`to a second Subscriber.
`
`19 Claims, 7 Drawing Sheets
`
`Channel/interference
`Variation Detection
`
`
`
`1101
`
`
`
`Yes
`
`
`
`Any
`Significant Variation
`Detected
`
`
`
`
`
`
`
`
`
`Select Diversity
`Clusters
`
`Select Coherence
`Clusters
`
`
`
`1
`
`GM 1018
`
`

`

`US 7,650,152 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`1/1994 Wang
`5,280,630 A
`1/1994 Fattouche et al.
`5,282,222 A
`7, 1995 Rappaport et al.
`5.437,054 A
`5,471,647 A 11/1995 Gerlach et al.
`5,479,447 A 12/1995 Chow et al.
`5,491,837 A
`2f1996 Haartsen
`5,504,775 A
`4/1996 Chouly et al.
`5,507,034 A
`4, 1996 Bodin et al.
`5,515,378 A
`5/1996 Roy, III et al.
`5,555,268 A
`9, 1996 Fattouche et al.
`5,588,020 A 12/1996 Schilling
`5,634,199 A
`5, 1997 Gerlach et al.
`5,708,973 A
`1/1998 Ritter et al.
`5,726,978 A
`3/1998 Frodigh et al.
`5,732,353 A
`3, 1998 Haartsen
`5,734,967 A
`3, 1998 Kotzin et al.
`5,764,699 A
`6/1998 Needham et al.
`5,774,808 A
`6/1998 Sarkioja et al.
`5,822,372 A 10/1998 Emami
`5,839,074. A 1 1/1998 Plehn et al.
`5,867.478 A
`2f1999 Baum et al.
`5,884, 145 A
`3, 1999 Haartsen
`5,886,988 A
`3, 1999 Yun et al.
`5,887,245 A
`3, 1999 Lindroth et al.
`5,909,436 A
`6/1999 Engstrometal.
`5,914,933 A
`6, 1999 Cimini et al.
`5,933,421 A
`8, 1999 Alamouti et al.
`5,956,642 A
`9, 1999 Larsson et al.
`5,973,642 A 10/1999 Li et al.
`5.991,273 A 1 1/1999 Abu-Dayya et al.
`6,005,876 A 12/1999 Cimini, Jr. et al.
`6,009,332 A 12/1999 Haartsen
`6,009,553 A 12/1999 Martinez et al.
`6,023,622 A
`2/2000 Plaschke et al.
`6,026,123 A
`2/2000 Williams
`6,038.450 A
`3, 2000 Brink et al.
`6,041,237 A
`3, 2000 Farsakh et al.
`6,052,594 A
`4/2000 Chuang et al.
`6,061,568 A
`5, 2000 Dent
`6,064,692 A
`5, 2000 Chow
`6,064,694. A
`5, 2000 Clarket al.
`6,067,290 A
`5/2000 Paulraj et al.
`6,091,717 A
`7/2000 Honkasalo et al.
`6,108,374. A
`8/2000 Balachandran et al.
`6,111,919 A
`8/2000 Yonge, III
`6,131,016 A 10, 2000 Greenstein et al.
`6,141,565 A 10, 2000 Feuerstein et al.
`6,144,696. A 1 1/2000 Shively et al.
`6, 192,026 B1
`2/2001 Pollack et al.
`6,208,663 B1
`3/2001 Schramm et al.
`6,226,320 B1
`5/2001 Hakkinen et al.
`6,276,297 B1
`8/2001 van den Berg et al.
`6,282,185 B1
`8/2001 Hakkinen et al.
`6,298,092 B1
`10/2001 Heath, Jr. et al.
`6,304,593 B1
`10/2001 Alouini et al.
`6,307,851 B1
`10/2001 Jung et al.
`6,327,472 B1
`12/2001 Westroos et al.
`6,330,460 B1
`12/2001 Wong et al.
`6.351,499 B1
`2/2002 Paulraj et al.
`6,351,643 B1
`2/2002 Haartsen
`6,366,195 B1
`4/2002 Harel et al.
`6,377,632 B1
`4/2002 Paulraj et al.
`6,377,636 B1
`4/2002 Paulraj et al.
`6,400,699 B1
`6/2002 Airy et al.
`6,404,783 B1
`6/2002 Cimini, Jr. et al.
`6,405,044 B1
`6/2002 Smith et al.
`6,405,048 B1
`6/2002 Haartsen
`6,411, 186 B1
`6/2002 Lilleberg et al.
`6,415, 153 B1
`7/2002 Liew
`6.424,836 B1
`7/2002 Gil et al.
`6,449.246 B1
`9/2002 Barton et al.
`
`10/2002 Raleigh et al.
`6.463,096 B1
`10/2002 Wallace et al.
`6,473.467 B1
`1 1/2002 Take et al.
`6,477,158 B1
`1 1/2002 Jones, IV et al.
`6,487.253 B1
`12/2002 Walton et al.
`6,493,331 B1
`12/2002 Andrews et al.
`6,496.490 B1
`12/2002 Chang et al.
`6,501,785 B1
`2/2003 Gorsuch et al.
`6,526,281 B1
`3/2003 Taketsugu et al.
`6,539,233 B1
`4/2003 Bohnke et al.
`6,545,997 B1
`4/2003 Indira
`6,553,001 B1
`4/2003 Florea
`6,553,234 B1
`5/2003 Bohnke et al.
`6,567,383 B1
`5/2003 Dulin et al.
`6,567,387 B1
`6/2003 Williams
`6,574.476 B1
`7/2003 Alamouti et al.
`6,600,776 B1
`1 1/2003 Avidor et al.
`6,654,612 B1
`12/2003 Jones, IV et al.
`6,657,949 B1
`2/2004 Gutowski ................... 370,335
`6,693,884 B1
`2/2004 Viswanath et al.
`6,694,147 B1
`3/2004 Xia et al.
`6,699,784 B2
`3/2004 Hashem et al.
`6,701,129 B1
`4/2004 Uesugi et al.
`6,726.297 B1
`7/2004 Catreux et al.
`6,760,882 B1
`8/2004 Krishnamoorthy et al.
`6,782,037 B1
`9, 2004 Wu et al.
`6,788,349 B2
`9/2004 Kapoor et al.
`6,795,424 B1
`12/2004 Lappetelainen et al.
`6,834,045 B1
`3/2005 Dulin et al.
`6,862,272 B2
`3/2005 Liu et al.
`6,870,808 B1
`6,904,283 B2 * 6/2005 Li et al. ...................... 455,450
`6,907,244 B2
`6/2005 Santhoff et al.
`6,920,122 B1
`7/2005 Hanaoka et al.
`6,922,445 B1
`7/2005 Sampath et al.
`6,928,120 B1
`8/2005 Zhang
`6,944,120 B2
`9, 2005 Wu et al.
`6,947,748 B2
`9/2005 Lietal.
`6,985,432 B1
`1/2006 Hadad et al.
`6,996,075 B2
`2/2006 Santhoffetal.
`6,996,100 B1
`2/2006 Haartsen
`7,047,011 B1
`5/2006 Wikman et al.
`7,072,315 B1
`7/2006 Liu et al.
`7,095,719 B1
`8/2006 Wilhelmsson et al.
`7,133,352 B1
`1 1/2006 Hadad
`7,133,380 B1
`1 1/2006 Winters et al.
`7,146,172 B2 * 12/2006 Li et al. ................... 455,452.1
`7.203,191 B2
`4/2007 Garcia-Luna-Aceves et al.
`7,230,908 B2
`6/2007 Vanderaar et al.
`7,373,151 B1
`5/2008 Ahmed
`7.379,742 B2 * 5/2008 Li et al. ................... 455,452.1
`2002/0114269 A1
`8/2002 Onggosanusi et al.
`2003, OO67890 A1
`4, 2003 Goel et al.
`2003. O169681 A1
`9, 2003 Li et al.
`2003. O169824 A1
`9/2003 Chayat
`2003,021 1831 A1 11/2003 Xu et al.
`2005, OO25099 A1
`2/2005 Heath et al.
`
`FOREIGN PATENT DOCUMENTS
`
`DE
`EP
`EP
`EP
`EP
`EP
`EP
`FR
`GB
`JP
`JP
`JP
`JP
`JP
`
`7, 1999
`198 OO 953 C1
`10, 1998
`O 869 647
`O 869 647 A2 10, 1998
`O882377 B1
`12/1998
`O 926912 A2
`6, 1999
`O929 202 A1
`T 1999
`O999658
`5, 2000
`27774O7 A1 10, 1999
`2,209 858 A
`5, 1989
`1-317035
`12/1989
`06029922
`2, 1994
`T-322219
`12/1995
`10-303849
`11, 1998
`11-088244
`3, 1999
`
`2
`
`

`

`US 7,650,152 B2
`Page 3
`
`JP
`KR
`WO
`WO
`WO
`WO
`WO
`WO
`
`11-3O8153
`1999-28244
`WO-96, 19055
`WO-97.01256
`WO-98, 16077 A2
`WO-98.30047 A1
`WO-00,004121
`WO-O249305 A2
`
`11, 1999
`4f1999
`6, 1996
`1, 1997
`4f1998
`7, 1998
`6, 2000
`6, 2002
`
`OTHER PUBLICATIONS
`English translation of Japanese Office Action for Application No.
`2002-550683, dispatched May 7, 2007, 2 ppgs.
`English translation of Japanese Office Action for Application No.
`2002-550747, dispatched May 21, 2007, 4 ppgs.
`European Office Action from Application No. 01986 165.7, dated
`Mar. 29, 2007, 5 ppgs.
`Farsakh, C. et al., “Maximizing the SDMA Mobile Radio Capacity
`Increase by DOA Sensitive Channel Allocation.” Wireless Personal
`Communications, Kluwer Academic Publishers, NL, vol. 11, No. 1.
`Oct. 1999, pp. 63-76, XP000835062, ISSN: 0929-6212.
`Frullone et al., PRMA Performance in Cellular Environments with
`Self-Adaptive Channel Allocation Strategies, IEEE Transactions on
`Vehicular Technology, Nov. 1996, pp. 657-665, vol. 45, No. 4.
`Farsakh, Cristofand Nossek, Josef A. On the Mobile Radio Capacity
`Increase through SDMA, no date (after 1997).
`Gruenheid, R. etal: "Adaptive Modulcation and Multiple Access for
`the OFDM Transmission Technique.” Wireless Personal Communi
`cations, Kluwer Academic Publishers, NL, vol. 13, NR. 1/2, Year
`2000, pp. 5-13 XPO008.94156, ISSN: 0929-6212.
`Kapoor, S. et al.: "Adaptive Interference Suppression in Multiuser
`Wireless, OFDM Systems. Using Antenna Arrays.” IEEE Transac
`tions on Signal Processing, vol. 47, No. 12, Dec. 1999, pp. 3381
`3391, XP000935422, IEEE, NY, USA, ISSN: 1053-587X.
`Kinugawa, Yet al.: “Frequency and Time Division Multiple Access
`with Demand-Assignment Using Multicarrier Modulation for Indoor
`Wireless Communications Systems.” IEICE Transactions on Com
`munications, Institute of Electronics Information and Comm. Eng.
`Tokyo, Japan, vol. E77-B, NR. 3, Mar. 1994, pp. 396-402,
`XP000451014, ISSN: 0916-8516.
`Motegi, M. et al.: Optimum Band Allocation According to Subband
`Condition for BST-OFDM 11th IEEE International Symposium on
`Personal Indoor and Modile Radio Communications, vol. 2, Sep.
`18-21, 2000, pp. 1236-1240, XP002213669, Piscataway, NJ, USA,
`ISBN: 0-7803-6463-5.
`Nogueroles, R. et al.: Improved Performance of a Random OFDMA
`Mobile Communication System: Vehicular Technology Conference,
`1998. VTC 98. 48th IEEE Ottawa, Ontario, Canada, May 18-21,
`1998, pp. 2502-2506, XPO 10288 120, ISBN: 0-7803-4320-4.
`Office Action issued for Korean Patent Application 2003-7007961
`dated Sep. 27, 2006.
`Shadet al., Indoor SDMA Capacity Using a Smart Antenna Basesta
`tion, 1997, IEEE, pp. 868-872.
`Tsoulos, G.V. Smart Antennas for Mobile Communication System:
`Benefits and Challenges, Electronics & Communication Engineering
`Journal, Apr. 1999, pp. 84-94.
`Vittoria Mignone et al. “CD3-OFDM: A Novel Demodulation
`Scheme for Fixed and Mobile Receivers.” IEEE Transactions on
`Communications, Sep. 1996, vol. 44, No. 9.
`Ward, James and Compton, R. Ted, Jr., High Throughput Slotted
`ALOHA Packet Radio Networks with Adaptive Arrays, IEEE Trans
`actions on Communications, Mar. 1993, pp. 460-470, vol. 41, No. 3.
`Wong, C.Y., et al., Multiuser OFDM With Adaptive Subcarrier, Bit,
`and Power Allocation, IEEE Journal on Selected Areas in Commu
`nications, Oct. 1999, IEEE Inc., New York, USA, vol. 17, No. 10, pp.
`1747-1758, XPO00855475.
`Xu, Guanghan and Li, San-Qi, Throughput Multiplication of Wire
`less Lans for Multimedia Services: SDMA Protocol Design, 1994
`IEEE, pp. 1326-1332.
`Ye Li, et al.: "Clustered OFDM with channel estimation for high rate
`wireless data.” Mobile Multimedia Communications, 1999.
`(MOMUC 99). 1999 IEEE International Workshop on San Diego,
`CA, USA, IEEE, US, Nov. 15, 1999, pp. 43-50.
`
`English Translation of the Office Action issued for Chinese Patent
`Application No. 2006 10081062.5, dated Apr. 3, 2009; 7 pages.
`Goldsmithet al., "Adaptive Coded Modulation for Fading Channels'.
`IEEE Transactions on Communications, vol. 46, No. 5, May 1998, 8
`pg.S.
`Goldsmith et al., “Variable-Rate Variable-Power MQAM for Fading
`Channels', IEEE Transactions on Communications, vol. 45, No. 10,
`Oct. 1997, 13 pgs.
`Czylwik, Adreas, "Adaptive Ofdm for Wideband Radio Channels'.
`IEEE 0/7803-3336-5/96, copyright 1996, 6 pgs.
`Doufexiet al., “A Comparison of Hiperlan/2 and IEEE802.11a Physi
`cal and MAC Layers”, IEEE 0/7803-6684-0/00, copyright 2000, 7
`pg.S.
`Arogyaswanni et al., "A Taxonomy of Space-Time Processing for
`Wireless Networks”, IEEE vol. 143, No. 1, Feb. 1998, 21 pgs.
`Wang et al., “Dynamic Channel Resource Allocation in Frequency
`Hopped Wireless Communication Systems'. IEEE 0-7803-2015-8,
`94, copyright 1994, 1 pg.
`Wong et al., “A Real-Time Sub-Carrier Allocation Scheme for Mul
`tiple Access Downlink OFDM Transmission”, IEEE 0-7803-5435
`4799, copyright 1999, 5 pgs.
`Wong et al., “Multiuser OFDM wit Adaptive Subcarrier, Bit and
`Power Allocation”, IEEE vol. 17, No. 10, Oct. 1999, 12 pgs.
`Wong et al., “Multiuser Subcarrier Allocation for OFDM Transmis
`sion Using Adaptive Modulation', IEEE 0-7803-5565-2/99, copy
`right 1999, 5 pgs.
`Sung et al., “User Speed Estimation and Dynamic Channel Alloca
`tion in Hierarchical Cellular System”, IEEE 0-7803-1927-3/94,
`copyright 1994, 5 pgs.
`Kivanc et al., “Subcarrier Allocation and Power control for Ofdma',
`IEEE 0-7803-6514-3/00, copyright 2000, 5 pgs.
`Grunheld et al., "Adaptive Modulation and Multiple Access for the
`OFDM Transmission Technique'. Wireless Personal Communica
`tions 13: 5-13, dated 2000, 9 pgs.
`Viswananthan et al., "Adaptive Coded Modulation Over Slow Fre
`quency-Selective Fading Channels', IEEE 0-7803-5585-2/99, copy
`right 1999, 5 pgs.
`Sari, Hikmet, “Trends and Challenges in Broadband Wireless
`Access”, IEEE 0-7803-6684-0/00, copyright 2000, 5 pgs.
`Sariet al., “An Analysis of Orthogonal Frequency-Division Multiple
`Access”, IEEE 0-7803-4198-8797, copyright 1997, 5 pgs.
`Toba et al., “A Demand-Assign Optical Frequency-Division-Mul
`tiple-Access Star Network”. Journal of Lightwave Technology, vol.
`11, No. 56, May/Jun. 1993, 7 pgs.
`Katzela et al., "Channel Assignment Schemes for Cellular Mobile
`Telecommunication Systems: A Comprehensive Survey', IEEE
`1070-9916/96, copyright 1996, 22 pgs.
`van de Beek et al., "A Time and Frequency Synchronization Scheme
`for Multiuser OFDM”, IEEE vol. 17, No. 11, Nov. 1999, 16 pgs.
`van de Beek et al., “On Channel Estimation in OFDM Systems',
`Preceedings of Vehicular Technology Conference (VTC 95) vol. 2,
`Sep. 1995, 6 pgs.
`Chuanget al., “Wideband Wireless Data Access Based on OFDM and
`Dynamic Packet Assignment”. IEEE 0-7803-5668-3/99, copyright
`1999, 5 pgs.
`Sathananthan et al., “Analysis of OFDM in the Presence of Fre
`quency Offset and a Method to Reduce Performance Degradation'.
`0-7803-6451-1/00, copyright 2000, 5 pgs.
`Keller et al., "Adaptive Modulation Techniques for Duplex OFDM
`Transmission', IEEE vol. 49, No. 5, Sep. 2000, 14pgs.
`Li et al., “A New Blind Receiver for Downlink DS-CDMA Commu
`nications”, IEEE vol. 3, No. 7, Jul. 1999, 3 pgs.
`Li et al., "Clustered OFDM with Channel Estimation for High Rate
`Wireless Data”, 1999 IEEE International Workshop, Nov. 15-17,
`1999, 9 pgs.
`Liu et al., “Efficient Network Utilization for Multimedia Wireless
`Networks', C.G. Omidyar (Ed.), MWCN 2000, copyright 2000, 15
`pg.S.
`Luise et al., "Carrier Frequency Acquisition and Tracking for OFDM
`Systems”, IEEE 0090-6778/96, copyright 1996, 9 pgs.
`Ericson et al., “Evaluation of the Mixed Service Ability for Competi
`tive Third Generation Multiple Access Technologies”, IEEE 0-7803
`3659-3/97, copyright 1997, 4pgs.
`
`3
`
`

`

`US 7,650,152 B2
`Page 4
`
`Wahlqvist et al., "Capacity Comparision of an OFDM Based Mul
`tiple Access System Using Different Dynamic Resource Allocation'.
`IEEE 0-7803-3659-3/97, copyright 1997, 5 pgs.
`Vanderaar, Mark et al., “Provisional Application', dated Jul. 24.
`2000, 11 pgs.
`Johnsson, Martin, "HiperLAN/2 - The Broadband Radio Transmis
`sion Technology Operating in the 5 GHZ Frequency Band”. Global
`Forum, 1999, 22 pgs.
`Olfat et al., "Adaptive Beamforming and Power Allocation for
`OFDM Over Wireless Networks”, IEEE 0-7803-5 148-7/98, copy
`right 1998, 5 pgs.
`Wahlqvist et al., “A Conceptual Study of OFDM-Based Multiple
`Access Schemes, Part 1: Air Interface Requirements”, Telia Research
`AB, Jun. 5, 1996, 6 pgs.
`Wahlqvist et al., Description of Telias OFDM Based Proposal (Work
`ing document in the OFDM concept group) Telia, ETSI STC
`SMG2#22, May 12-16, 1997, 22 pgs.
`Mehta et al., “Performance Analysis of Link Adaptation in Wireless
`Data Networks'. Department of Electrical Engineering, Stanford
`University, Mar. 6, 2000, 15 pgs.
`Author Unknown, "Part 11: Wireless Lan Medium Access Control
`(MAC) and Physical Layer (PHY) specifications: High-Speed Physi
`cal Layer in the 5 GHZ, Band", IEEE Supplement, Sep. 16, 1999,90
`pg.S.
`Robertson et al., “The Effects of Doppler Spreads in OFDM(A)
`Mobile Radio Systems”, IEEE0/7803-5435-4, copyright 1999, Insti
`tute for Communications Technology, German Aerospace Center
`(DLR), 5 pgs.
`Knopp et al., “Information Capacity and Power Control in Single
`Cell Multiuser Communications”, IEEE 0/7803-2486-2/95, copy
`right 1995, 5 pgs.
`Rohling et al., "Adaptive Coding and Modulation in an OFDM
`TDMA Communication System”, IEEE 0/7803-4320-4/98, copy
`right 1998, 4pgs.
`Nogueroles et al., “Improved Performance of a Random OFDMA
`Mobile Communication System”, IEEE 0/7803-4320-4/98, copy
`right 1998, 5 pgs.
`Nogueroles et al., “Performance of a Random OFDMA System for
`Mobile Communications”, IEEE 0/7803-3893-6/98, copyright 1998,
`7 pgs.
`van Nee et al., “OFDM for Wireless Multimedia Communications',
`Artech House Universal Personal Communications, copyright 2000,
`14pgs.
`Heath et al., "Coordinated Training and Transmission for Improved
`Interference Cancellation in a Cellular Network', IEEE 0-803-6514
`3/00, copyright 2000, 7 pgs.
`Rohling et al., “Performance Comparison of Different Multiple
`Access Schemes for the Downlink of an OFDM Communication
`System”, IEEE 0/7803-3659-3/97, copyright 1997, 5 pgs.
`
`Sartenaer et al., “Resource Allocation for Frequency-Selective Mul
`tiple Access Channels with Adaptive QAM Modulation', IEEE
`0/7803-6684-00, copyright 2000, 8 pgs.
`Seong-Jun Oh et at "Adaptive Resource Allocation in Power Con
`strained Cdma Mobile Networks”, IEEE 0/7803-5668-3/99, copy
`right 1999, 5 pgs.
`Slawomir et al., “Multiuser Subcarrier Allocation for QoS Provision
`in the OFDMA Systems”, IEEE 0/7803-7467-3/02, copyright 2002,
`5 pgs.
`Sollenberger et al., “Receiver Structure for Multiple Access OFDM'.
`IEEE 0/7803-5565-2/99, copyright 1999, 5 pgs.
`Papavassiliou et al., "Joint Optimal Channel Base Station and Power
`Assignment for Wireless Access'. Polytechnic University, Published
`Jun. 17, 1996, 35 pgs.
`Maehata et al., “DSRC Using OFDM for Roadside-Vehicle Commu
`nication System”, IEEE 0-7803-5718-3/00, copyright 2000, 5 pgs.
`Keller et al., "Adaptive Modulation Techniques for Duplex OFDM
`Transmission'. Department of Electronics and Computer Science,
`University of Southhampton, Jun. 7, 1999, 14 pages.
`Tufvesson et al., “Pilot Assisted Channel Estimation for OFDM in
`Mobile Cellular Systems'. Department of Applied Electronics, Lund
`University, VTC 1997, 5 pgs.
`Rhee et al., “Increase in Capacity of Multiuser OFDM System Using
`Dynamic Subchannel Allocation”, IEEE 0/7803-5718-3/00, copy
`right 2000, 5 pgs.
`Li et al., “Maximum-Likelihood Estimation of OFDM Carrier Fre
`quency Offset for Fading Channels', IEEE 1058-6393/98, copyright
`1998, 5 pgs.
`Li et al., “M-Sequences for OFDM Peak-to-Average Power Ration
`Reduction and Error correction'. Electronics Letters, vol. 33, No. 7,
`Mar. 27, 1997, 2 pgs.
`Li et al., “Effects of Clipping and Filtering on the Performance of
`OFDM”, IEEE Conference on Vehicular Technology, 1997, 3 pgs.
`Li et al., “Effects of Clipping and Filtering on the Performance of
`OFDM, IEEE 0-7803-3659-3/97, copyright 1997, 5 pgs.
`Tang et al., “An Adaptive Modulation Scheme for Simultaneous
`Voice and Data Transmission Over Fading Channels', IEEE Vehicu
`lar Technology Conference (VTC 98), draft dated Dec. 1, 1997, 32
`pg.S.
`Matsui et al., “OFDMA/TDD Packet Transmission System with an
`Adaptive Subcarrier Selection Scheme for Asymmetric Wireless
`Communication Services', IEEE 0-803-6622-0/01, copyright 2001,
`2 pgs.
`Li et al., “Channel Estimation for OFDM Systems with Transmitter
`Diversity in Mobile Wireless Channels”, IEEE 0733-8716/99, copy
`right 1999, 11 pgs.
`* cited by examiner
`
`4
`
`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 1 of 7
`
`US 7.650,152 B2
`
`Subcarrier
`101 ;
`
`Cluster
`102
`
`F.G. 1A
`
`Cluster A
`Custer B
`
`
`
`f
`
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`
`Pilot OFDM
`Symbols
`
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`201N N S S
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`Occupied Clusters
`a. Cell A
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`
`5
`
`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 2 of 7
`
`US 7,650,152 B2
`
`
`
`Retraining
`Needed
`
`
`
`
`
`No
`
`Periodically Broadcast Pilot
`OFDM Symbols to Subscribers
`
`101
`
`Subscriber(s) Continuously Monitors
`Pilot Symbols/Measures SiNRandlor -102
`Other Parameters
`
`Each Subscriber Selects One or More
`Clusters for Each Base Station
`
`103
`
`
`
`
`
`
`
`Base Station Selects One or More
`Clusters for Each Subscriber
`
`104
`
`Base Station Notifies the Subscriber
`Regarding Cluster Allocation
`
`105
`
`F.G. 1B
`
`6
`
`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 3 of 7
`
`US 7,650,152 B2
`
`
`
`
`
`
`
`
`
`
`
`
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`
`|
`
`7
`
`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 4 of 7
`
`US 7,650,152 B2
`
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`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 5 of 7
`
`US 7,650,152 B2
`
`1-8: Diverse Clusters
`
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`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 6 of 7
`
`US 7,650,152 B2
`
`Channel/interference
`Variation Detection
`
`
`
`
`
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`
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`10
`
`

`

`U.S. Patent
`
`Jan. 19, 2010
`
`Sheet 7 of 7
`
`US 7,650,152 B2
`
`User Data Buffer information
`1311
`
`
`
`
`
`
`
`
`
`1301
`
`Admission Control
`
`
`
`
`
`
`
`
`
`Cluster Allocation and
`Load Scheduling
`Controller
`
`Multi-user Data
`Buffer
`
`Multiplexe?
`
`SNRIRate
`indices
`
`
`
`Multi-cluster
`Transmission and
`Receiving Buffer
`
`
`
`
`
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`
`1302
`
`1303
`
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`
`1304
`
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`
`
`
`
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`1312
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`
`FG, 13
`
`11
`
`

`

`US 7,650,152 B2
`
`1.
`MULTI-CARRIER COMMUNICATIONS WITH
`ADAPTIVE CLUSTER CONFIGURATION
`AND SWITCHING
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a Continuation of U.S. patent applica
`tion Ser. No. 1 1/592,084 filed Nov. 2, 2006 entitled MULTI
`CARRIER COMMUNICATIONS WITH ADAPTIVE
`10
`CLUSTER CONFIGURATION AND SWITCHING, which
`is a Continuation of U.S. Pat. No. 7,146,172 issued Dec. 5,
`2006 entitled MULTI-CARRIER COMMUNICATIONS
`WITH ADAPTIVE CLUSTER CONFIGURATION AND
`SWITCHING, which is a Continuation-in-Part of U.S. Pat.
`15
`No. 6,947,748 issued Sep. 20, 2005, entitled OFDMAWITH
`ADAPTIVE SUBCARRIER-CLUSTER CONFIGURA
`TION AND SELECTIVE LOADING, the disclosures of
`which are incorporated herein by reference.
`
`FIELD OF THE INVENTION
`
`The invention relates to the field of wireless communica
`tions; more particularly, the invention relates to multi-cell,
`multi-subscriber wireless systems using orthogonal fre
`quency division multiplexing (OFDM).
`
`25
`
`BACKGROUND OF THE INVENTION
`
`2
`Bit and Power Allocation.” IEEE J. Select. Areas Commun.,
`Vol. 17(10), pp. 1747-1758, October 1999.
`Within one cell, the subscribers can be coordinated to have
`different subcarriers in OFDMA. The signals for different
`subscribers can be made orthogonal and there is little intracell
`interference. However, with aggressive frequency reuse plan,
`e.g., the same spectrum is used for multiple neighboring cells,
`the problem of intercell interference arises. It is clear that the
`intercell interference in an OFDMA system is also frequency
`selective and it is advantageous to adaptively allocate the
`subcarriers so as to mitigate the effect of intercell interfer
`CCC.
`One approach to subcarrier allocation for OFDMA is a
`joint optimization operation, not only requiring the activity
`and channel knowledge of all the subscribers in all the cells,
`but also requiring frequent rescheduling every time an exist
`ing subscriber is dropped off the network or a new subscriber
`is added onto the network. This is often impractical in real
`wireless system, mainly due to the bandwidth cost for updat
`ing the Subscriber information and the computation cost for
`the joint optimization.
`
`SUMMARY OF THE INVENTION
`
`A method and apparatus for allocating Subcarriers in an
`orthogonal frequency division multiple access (OFDMA)
`system is described. In one embodiment, the method com
`prises allocating at least one diversity cluster of subcarriers to
`a first Subscriber and allocating at least one coherence cluster
`to a second Subscriber.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present invention will be understood more fully from
`the detailed description given below and from the accompa
`nying drawings of various embodiments of the invention,
`which, however, should not be taken to limit the invention to
`the specific embodiments, but are for explanation and under
`standing only.
`FIG. 1A illustrates subcarriers and clusters.
`FIG. IB is a flow diagram of one embodiment of a process
`for allocating Subcarriers.
`FIG. 2 illustrates time and frequency grid of OFDM sym
`bols, pilots and clusters.
`FIG. 3 illustrates subscriber processing.
`FIG. 4 illustrates one example of FIG. 3.
`FIG. 5 illustrates one embodiment of a format for arbitrary
`cluster feedback.
`FIG. 6 illustrates one embodiment of apartition the clusters
`into groups.
`FIG. 7 illustrates one embodiment of a feedback format for
`group-based cluster allocation.
`FIG. 8 illustrates frequency reuse and interference in a
`multi-cell, multi-sector network.
`FIG. 9 illustrates different cluster formats for coherence
`clusters and diversity clusters.
`FIG. 10 illustrates diversity clusters with subcarrier hop
`ping.
`FIG. 11 illustrates intelligent switching between diversity
`clusters and coherence clusters depending on Subscribers
`mobility.
`FIG. 12 illustrates one embodiment of a reconfiguration of
`cluster classification.
`FIG. 13 illustrates one embodiment of a base station.
`
`30
`
`Orthogonal frequency division multiplexing (OFDM) is an
`efficient modulation scheme for signal transmission over fre
`quency-selective channels. In OFDM, a wide bandwidth is
`divided into multiple narrowband subcarriers, which are
`arranged to be orthogonal with each other. The signals modu
`lated on the subcarriers are transmitted in parallel. For more
`35
`information, see Cimini, Jr., “Analysis and Simulation of a
`Digital Mobile Channel Using Orthogonal Frequency Divi
`sion Multiplexing.” IEEE Trans. Commun., vol. COM-33,
`no. 7, July 1985, pp. 665-75; Chuang and Sollenberger,
`“Beyond 3G: Wideband Wireless Data Access Based on
`40
`OFDM and Dynamic Packet Assignment.” IEEE Communi
`cations Magazine, Vol. 38, No. 7, pp. 78-87, July 2000.
`One way to use OFDM to support multiple access for
`multiple Subscribers is through time division multiple access
`(TDMA), in which each subscriber uses all the subcarriers
`within its assigned time slots. Orthogonal frequency division
`multiple access (OFDMA) is another method for multiple
`access, using the basic format of OFDM. In OFDMA, mul
`tiple subscribers simultaneously use different subcarriers, in a
`fashion similar to frequency division multiple access
`(FDMA). For more information, see Sari and Karam,
`“Orthogonal Frequency-Division Multiple Access and its
`Application to CATV Networks. European Transactions on
`Telecommunications, Vol. 9 (6), pp. 507-516, November/
`December 1998 and Nogueroles, Bossert, Donder, and
`55
`Zyablov, “Improved Performance of a Random OFDMA
`Mobile Communication System.” Proceedings of IEEE
`VTC 98, pp. 2502-2506.
`Multipath Causes Frequency-Selective Fading. The chan
`nel gains are different for different subcarriers. Furthermore,
`the channels are typically uncorrelated for different subscrib
`ers. The subcarriers that are in deep fade for one subscriber
`may provide high channel gains for another subscriber.
`Therefore, it is advantageous in an OFDMA system to adap
`tively allocate the subcarriers to subscribers so that each
`Subscriber enjoys a high channel gain. For more information,
`see Wong et al., “Multiuser OFDM with Adaptive Subcarrier,
`
`45
`
`50
`
`60
`
`65
`
`12
`
`

`

`3
`DETAILED DESCRIPTION OF THE PRESENT
`INVENTION
`
`US 7,650,152 B2
`
`5
`
`10
`
`15
`
`4
`For either direction, the base station makes the final deci
`sion of subcarrier allocation for each subscriber.
`In the following description, a procedure of selective sub
`carrier allocation is also disclosed, including methods of
`channel and interference sensing, methods of information
`feedback from the subscribers to the base station, and algo
`rithms used by the base station for subcarrier selections.
`In the following description, numerous details are set forth
`to provide a thorough understanding of the present invention.
`It will be apparent, however, to one skilled in the art, that the
`present invention may be practiced without these specific
`details. In other instances, well-known structures and devices
`are shown in block diagram form, rather than in detail, in
`order to avoid obscuring the present invention.
`Some portions of the detailed descriptions which follow
`are presented in terms of algorithms and symbolic represen
`tations of operations on data bits within a computer memory.
`These algorithmic descriptions and representations are the
`means used by those skilled in the data processing arts to most
`effectively convey the substance of their work to others
`skilled in the art. An algorithm is here, and generally, con
`ceived to be a self-consistent sequence of steps leading to a
`desired result. The steps are those requiring physical manipu
`lations of physical quantities. Usually, though not necessarily,
`these quantities take the form of electrical or magnetic signals
`capable of being stored, transferred, combined, compared,
`and otherwise manipulated. It has proven convenient at times,
`principally for reasons of common usage, to refer to these
`signals as bits, values, elements, symbols, characters, terms,
`numbers, or the like.
`It should be borne in mind, however, that all of these and
`similar terms are to be associated with the appropriate physi
`cal quantities and are merely convenient labels applied to
`these quantities. Unless specifically stated otherwise as
`apparent from the following discussion, it is appreciated that
`throughout the description, discussions utilizing terms such
`as “processing or “computing or "calculating or “deter
`mining or “displaying or the like, refer to the action and
`processes of a computer system, or similar electronic com
`puting device, that manipulates and transforms data repre
`sented as physical (electronic) quantities within the computer
`system's registers and memories into other data similarly
`represented as physical quantities within the computer sys
`tem memories or registers or other Such information storage,
`transmission or display devices.
`The present invention also relates to apparatus for perform
`ing the operations herein. This apparatus may be specially
`constructed