Block spreading CDMA system: a simplified scheme using despreading before equalisation for broadband uplink transmission

A block-spreading code division multiple access (BS-CDMA) system is proposed for broadband uplink transmission, giving rise to a significantly improved multiuser performance without using complex multiuser detection techniques. This is because the code orthogonality is easily maintained when channel variation across the consecutive blocks, in a block-by-block high-speed transmission, is negligible. The proposed system uses frequency domain equalisation at the receiver to combat multipath interference efficiently over frequency selective fading channels. We propose despreading before equalisation, which reduces the frequency domain process to symbol-wise operation. A cell-specific scrambling code is employed to suppress other-cell interference for uplink transmission in a multicell system. Our analytical and simulation studies show that the proposed BS-CDMA system has superior multiuser performance over the conventional direct sequence CDMA and cyclic prefix CDMA systems for uplink transmission.

[1]  David Falconer,et al.  Frequency domain equalization for single-carrier broadband wireless systems , 2002, IEEE Commun. Mag..

[2]  Fumiyuki Adachi,et al.  Bit Error Rate Analysis of DS-CDMA with Joint Frequency-Domain Equalization and Antenna Diversity Combining , 2004 .

[3]  Ramjee Prasad,et al.  Design and performance of multicarrier CDMA system in frequency-selective Rayleigh fading channels , 1999 .

[4]  John G. Proakis,et al.  Digital Communications , 1983 .

[5]  Xianda Zhang,et al.  Peak-to-average power ratio analysis in multicarrier DS-CDMA , 2003, IEEE Trans. Veh. Technol..

[6]  Ying-Chang Liang,et al.  Single Carrier Cyclic Prefix-Assisted CDMA System with Frequency Domain Equalization for High Data Rate Transmission , 2004, EURASIP J. Wirel. Commun. Netw..

[7]  Leonard J. Cimini,et al.  On the use of a cyclic extension in OFDM , 2001, IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211).

[8]  Hikmet Sari,et al.  Orthogonal frequency-division multiple access and its application to CATV networks , 1998, Eur. Trans. Telecommun..

[9]  Friedrich K. Jondral,et al.  Low complexity CDMA downlink receiver based on frequency domain equalization , 2003, 2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484).

[10]  Mamoru Sawahashi,et al.  Downlink transmission of broadband OFCDM Systems-part I: hybrid detection , 2005, IEEE Transactions on Communications.

[11]  Georgios B. Giannakis,et al.  Bandwidth- and power-efficient multi-carrier multiple access , 2003, 2003 IEEE Wireless Communications and Networking, 2003. WCNC 2003..

[12]  A. S. Madhukumar,et al.  Novel two-dimensional multistage interference cancellation scheme for uplink transmission of single carrier cyclic prefix-assisted CDMA system , 2003 .

[13]  Romano Fantacci,et al.  Proposal of an interference cancellation receiver with low complexity for DS/CDMA mobile communication systems , 1999 .

[14]  Georgios B. Giannakis,et al.  Chip-interleaved block-spread CDMA versus DS-CDMA for cellular downlink: a comparative study , 2004, IEEE Transactions on Wireless Communications.

[15]  Kevin L. Baum,et al.  Cyclic-prefix CDMA: an improved transmission method for broadband DS-CDMA cellular systems , 2002, 2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609).

[16]  Georgios B. Giannakis,et al.  Chip-interleaved block-spread code division multiple access , 2002, IEEE Trans. Commun..

[17]  Georgios B. Giannakis,et al.  Bandwidth- and power-efficient multicarrier multiple access , 2003, IEEE Trans. Commun..

[18]  Hiroyuki Atarashi,et al.  Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) , 2002 .

[19]  Mamoru Sawahashi,et al.  Variable Spreading and Chip Repetition Factors (VSCRF)-CDMA in Reverse Link for Broadband Packet Wireless Access , 2005, IEICE Trans. Commun..

[20]  Fumiyuki Adachi,et al.  Wideband DS-CDMA for next-generation mobile communications systems , 1998, IEEE Commun. Mag..

[21]  Milica Stojanovic,et al.  Performance of adaptive MC-CDMA detectors in rapidly fading Rayleigh channels , 2003, IEEE Trans. Wirel. Commun..