Adaptive interference-free spread-spectrum system employing binary code sequence sets with zero correlation zone properties
AssigneesPingzhi Fan, Naoki Suehiro, Noriyoshi Kuroyanagi, Toyo Communication Equipment Co., Ltd., Daiei Electronics Co., Ltd.
InventorsPingzhi Fan, Naoki Suehiro, Noriyoshi Kuroyanagi
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Abstract
A direct sequence spread spectrum system consisting of modulator and demodulator wherein the spreading sequence with zero correlation zone properties, and the despreading consists of multiplying the received signal with the same spreading sequence, followed by a low pass filter, decoder and deinterleaver. The bit rate of the spreading sequence for each user is normally much higher than the input encoded data bit rate, and therefore it spreads the system spectrum.
Claims11
A binary coded direct sequence spread spectrum communication system comprising a means for generating a binary spreading sequence set of length L and size M used in the system having a zero correlation zone ZCZ in their periodic autocorrelation functions on both sides of the zero shift and a zero correlation zone ZCZ in the periodic cross-correlation functions including the zero shift between any pair of spreading sequences belonging to the code sequence set wherein said binary spreading sequence set has length L=2×2i×10j×26k, where i, j, k can be zeroes or any positive integers, and family size 2<M<L, and zero correlation zone ZCZ≦L/M+1 for any permitted values of i, j, k, or ZCZ=L/M+1 for j=k=0 and any permitted value of i and comprises ZCZ sequence(s) and further comprises a means for generating a central frame by multiplying a binary input and said ZCZ sequence(s), and additional guard sequences enclosing the central frame, said additional guard sequence being extracted from parts of the central frame.
Dependencies are inferred from the claim text.