Patent ID: 6842442

Claim:
A DS-CDMA transmission method using a code multiplexing method which transmits a transmission signal generated by code multiplexing through a plurality of code channels, said DS-CDMA transmission method comprising the steps of: coding an input data sequence, distributing the coded input data sequence to a plurality of data sequences in said plurality of code channels, and canying out interleaving for each of said plurality of said data sequences to which the coded input data sequence has been distributed; assembling frames for one of said code channels by adding pilot symbols to said interleaved data symbols in said data sequence at fixed intervals, said pilot symbols being used for channel estimation for coherent detection, and assembling frames for one or more code channels other than said one of said code channels including said interleaved data symbols without adding the pilot symbols; and spreading said interleaved data symbols in each of said plurality of code channels using a spreading code peculiarly assigned to said each of said plurality of code channels, said spreading code being selected from a group of orthogonal spreading codes that are orthogonal to each other, and spreading said pilot symbols, which are included in only one channel of said plurality of code channels, using one of the spreading codes being selected from said spreading codes assigned to said interleaved data symbols in said plurality of code channels, or any of the spreading codes from said group of orthogonal spreading codes other than the spreading codes assigned to said interleaved data symbols in said plurality of code channels.