| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and device for achieving variability of channels for use by a spread spectrum communication system. SOLUTION: The method and device are disclosed for demodulating communication signals via 4n×4n orthogonal Hadamard spread spectrum codes to be used in a CDMA environment. To obtain flexibility in adding channels for a variety of multimedia applications and improve flexibility between the number of channels and the bandwidth, orthogonal spread codes whose length of not a power of two are used. The use of Hadamard codes whose length is a multiple of 4 (4n) ensures good cross-correlation properties and provides significant advantage for flexible CDMA system design. A transmitter encodes each of N (not equal to a power of two) transmission data streams by using code words Ni, each having a length of 4n. A receiver passes the received signals through a filter adjusted to properties of an adequate code word Ni and a PN spread sequence. COPYRIGHT: (C)2008,JPO&INPIT |
