| 摘要 |
PURPOSE: To realize the multiplex spread spectrum communication in which a correlation peak level is not deteriorated. CONSTITUTION: A tip number N of a reference spread spectrum code (SS0) is set to be m×k (m is the number of multiplex such as m=3 and k is an integer being 2 or over such as k=4), the autocorrelation is incremented by 1 for each synchronization T=NTp (Tp is a tip length), and a code taking 0 for each k×Tp in each period such as '111001101000' is used. A polyphase SS code generating section 16 gives an i-th phase code resulting from obtained by delaying SS0 by a time of (i-1)kTp as an i-th channel (i=1-m) SS code (SSi) to a multiplier section, from which SS data fn }, gn }, hn } multiplied with input data (±1) are obtained. They are added to obtain tetral multiplex SS data xn } of 0, 1, 2, 3 levels, which are converted into a tetra phase modulation signal, for example. An intercorrelation R (τ) is obtained with the SS' from the data xn } demodulated by a receiver and its peak level (±1) is detected and its detection output y (τ) is distributed to each channel by a demultiplexer 23. |
