Title :
TDD-CDMA Downlink precoding with Channel Mismatch Error
Author :
Kejalakshmi, V. ; Arivazhagan, S.
Author_Institution :
Dept. of Electron. & Commun. Eng., K.L.N. Coll. of Eng., Pottapalayam, India
Abstract :
Recently research has been focused on techniques that simplify the mobile receiver structure in CDMA systems by means of precoding. It is known that when channel state information (CSI) is available at the transmitter a large performance gain can be achieved. In a system employing time-division duplexing (TDD), CSI can be obtained at the base station if there is reciprocity between the forward and reverse channels. In any case, channel estimation errors are inevitable due to the presence of background noise in the estimated signal and due to the finite number of feedback bits used in a limited-rate feedback system model. In this paper, MMSE based precoding technique has been derived by considering channel estimation errors as an integral part of the system design. Simulation results are provided which demonstrate significant performance improvement when compared to the chip-wise linear precoding.
Keywords :
channel estimation; code division multiple access; least mean squares methods; precoding; radio receivers; radio transmitters; time division multiplexing; MMSE; TDD-CDMA downlink precoding; channel estimation errors; channel mismatch error; channel state information; chip wise linear precoding; forward channel; mobile receiver structure; radio transmitter; reverse channel; time division duplexing; Base stations; Channel estimation; Downlink; Feedback; Filters; Mobile communication; Multiaccess communication; Multiuser detection; Radio transmitters; Receivers; Minimum Mean Square Error (MMSE); Time-division-duplex code-division multiple access (TDD-CDMA);
Conference_Titel :
Advances in Recent Technologies in Communication and Computing, 2009. ARTCom '09. International Conference on
Conference_Location :
Kottayam, Kerala
Print_ISBN :
978-1-4244-5104-3
Electronic_ISBN :
978-0-7695-3845-7
DOI :
10.1109/ARTCom.2009.136