Patent ID: 7167456

Claim:
An apparatus for estimating propagation path characteristics in a communication system in which information is transmitted upon being code-multiplexed onto a data channel on which known information is transmitted upon being time-multiplexed between items of unknown information and a data channel on which only unknown information is transmitted, said apparatus comprising: a first transmit information removal unit for removing, from a receive signal on a data channel on which known information is transmitted upon being time-multiplexed between items of unknown information, transmit information on this channel; a second transmit information removal unit for removing, from a receive signal on a data channel on which only unknown information is transmitted, transmit information on this channel; an adder for adding outputs from said first and second transmit information removal units; and a phase/amplitude estimation unit for estimating, from an output of said adder, a phase characteristic and an amplitude characteristic that each channel has suffered over a propagation path.