An M-ary Spread Spectrum Receiver Based on Orthogonal Cyclic Codes
Chu Zhen-yong①②; Ying Xiao-fan①; Yi Ke-chu①; Tian Hong-xin①
①National Key Lab. of ISN, Xidian University, Xi’an 710071, China;②Telecommunication Engineering Institute, Air Force Engineering University, Xi’an 710077, China
Abstract：This paper proposes a novel M-ary spread spectrum receiver scheme based on time-frequency transform domain. At the transmitter of the system, the M spreading codes of each user are generated by circularly shifting the prototype spreading code. At the receiver, a time-frequency transform domain orthogonal matched-filter is employed to noncoherently despread and demodulate the received signals. The proposed scheme reduces computation and spreading codes selection difficulty of M-ary spread spectrum system remarkably. The BER performances of the receiver for single user and multiuser are analyzed, and the computations for three kinds of M-ary despreading methods are compared. The results show that the proposed scheme has better BER performance and lower computation complexity than of traditional M-ary systems.
2005, Vol. 27 
