Patent ID: 7203156
Filing Date: 2007-04-10
Classification: H04L

Abstract:
1. A base station device for carrying out bidirectional data communication with a communication terminal device, the base station device comprising: transmission means for carrying out communication of a down link to the communication terminal device by using a multi-carrier signal having data dispersed to m units of subcarriers for transmission by applying an orthogonal frequency division multiplex (OFDM); receiving means for receiving a multi-carrier signal having the data dispersed to m or j units of subcarriers or for receiving a single-carrier signal transmitted from the communication terminal device and for demodulating the data thereof; and discrimination means for discriminating a received signal among the multi-carrier signal using m units of subcarriers, or the multi-carrier signal using only j units of subcarriers, or the single-carrier signal, such that demodulation process g conforming to a the received signal is carried out by the receiving means based upon a result of discrimination of the discrimination means, wherein m is an integer not smaller than 2; and j is an integer smaller than m, and including error detecting means for detecting errors in the received signal before the discriminating operation.