000 04365nas|a2200445 i 4500
005 20260817172700.0
008 020717s2001 th u m rtt 00| a1eng d
035 _a.b11861289
099 9 _aAIT Thesis no.TC-01-08
100 0 _aLai Xuan Tung
245 1 0 _aChip level LMMSE equalizer receivers in downlink of the wideband code division multiple access system
260 _aBangkok :
_bAsian Institute of Technology,
_c2001
300 _a55 p.
490 1 _aThesis ;
_vno. TC-01-08
500 _aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology
502 _aThesis (M.Eng.) - Asian Institute of Technology, 2001
520 _aAs demand for wireless communications continues to grow, third-generation cellular communications systems are being standardized to provide flexible voice and data services. Third-generation Wideband Code Division Multiple Access (WCDMA) systems promise significantly higher data rates (up to 2 Mbits/s) and a new array of mobile communication services, such as video teleconferencing and web browsing, which especially require uplink and downlink performance improvement. In the near future, the downlink capacity is expected to be more crucial than the capacity of the uplink due to the asymmetric capacity requirements, i.e., the downlink direction should offer higher capacity than the uplink. Therefore the employment of efficient downlink receivers is important. One promising approach is to use chip level channel equalizer type downlink receiver. In the thesis, performance of the adaptive chip level Linear Minimum Mean Square Error Equalizer receivers for downlink of WCDMA systems employing long scrambling code is studied over a correlated Rayleigh multipath fading channel through simulation. The adaptive chip level Linear Minimum Mean Square Error Equalizer receivers and conventional Rake receiver are implemented in this simulation based on the parameters closely matched to UMTS/IMT 2000 requirement. Two adaptive LMMSE equalization techniques for downlink WCDMA with QPSK modulation have been studied: estimating the inverse matrix and using Griffiths' algorithms. Performance of both adaptive equalization techniques has been investigated and compared with Conventional Rake receivers in a correlated fading environment. The adaptive chip level LMMSE Equalizer receivers essentially estimate the multiuser chip and thus, restore the orthogonality between different own cell users' signal. Simulation results show that while the conventional Rake receiver is impaired very much by the interfering user's signal, LMMSE equalizer receiver can sustain the effects of MAL The adaptive chip level LMMSE Equalizer receivers give superior performance to the conventional Rake since they are able to suppress intracell MAI based on equalizing the effects of the multipath channel. Based on the simulation results, it is shown that the method of estimating inverse matrix gives slightly better performance than the Griffiths' algorithms.
650 1 0 _aCode division multiple access
650 1 0 _aBroadband communication systems
650 1 0 _aEqualizers (Electronics)
700 1 _aMakelainen, Kimmo,
_eChairperson
700 1 _aAhmed, Kazi Mohiuddin,
_eExamination Committee
700 1 _aSharma, A.B.,
_eExamination Committee
710 2 _aGovernment of Finland,
_eScholarship donor
810 2 _aAsian Institute of Technology.
_tThesis ;
_vno. TC-01-08
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B11034
907 _a.b11861289
_bmnait
_cu
902 _a240402
998 _b0
_c020717
_dm
_ea
_fu
_g0
945 _lmnait
945 _lmnait
945 _lmnarc
942 _c22
942 _c40
942 _c20
909 _aBarcode : 30050120810071
_bCREATED : 2014-10-04
_cRECORD # : i12789495
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
909 _aBarcode : 30050160045174
_bCREATED : 2016-03-03
_cRECORD # : i12888606
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
909 _aBarcode : 30050211032486
_bCREATED : 2021-04-30
_cRECORD # : i13341819
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
999 _c17076
_d17076