Patent ID: 8437316

Claim:
A CDMA radio transmission apparatus comprising: a multiplexer that multiplexes a midamble sequence that is one of a plurality of midamble sequences with data for one CDMA radio reception apparatus to generate a transmission signal; and a transmitter that transmits the transmission signal to the CDMA radio reception apparatus in one communication channel among a plurality of other CDMA communication channels, wherein: the multiplexer switches every unit time the midamble sequence among a plurality of different midamble sequences according to an assignment change pattern that defines a change of assignment patterns for every unit time, each of the assignment patterns defining midamble sequences assigned to a plurality of communication channels with the CDMA radio reception apparatus during the communication with the CDMA radio reception apparatus; each midamble sequence of the plurality of midamble sequences is obtained by sequentially shifting a basic code by a multiple of a predetermined amount in a predetermined direction; and for every unit time, the periodically switched midamble sequence according to the assignment pattern is different from any other midamble sequence of the plurality of midamble sequences used for the remaining plurality of CDMA communication channels.