Proposal of an alternate M-sequence spread spectrum system
Noriyoshi Kuroyanagi, Liang Guo · 2002
The authors propose a spreading sequence that expands the design flexibility of spread spectrum systems. This new sequence, called the AM-sequence is created by multiplying a short M-sequence by a line of an N /spl times/ N Hadamard matrix. Because of the frequency characteristics and orthogonal functionality of a Hadamard matrix, each AM-sequence has frequency characteristics that do not have components duplicating those of other AM-sequences. There is therefore little mutual correlation between these derived sequences. This lack of correlation provides an effective method for avoiding the near-far problem or for overcoming narrowband interference in a spread spectrum mobile communications system. Various methods for composing AM-sequences are explored, and an experiment and correlation estimation are presented in order to show the effectiveness of AM-sequences in avoiding interference.>