1. Field of the Invention
The present invention relates to a radio communication system employing a communication scheme using multi-carrier modulation such as OFDM (Orthogonal Frequency Division Multiplexing).
2. Description of the Related Art
According to conventional AMC (Adaptive Modulation and Coding), a mobile station has measured the radio transmission path quality based on a receive signal from a base station, and the transmission format has been selected from a preset table MCS (Modulation and Coding set) on the basis of the measurement result.
In a system employing CDM (Code Division Multiplexing) as the multiplexing scheme, even if the AMC is employed, interference between radio zones (cells) formed by the respective base stations is identified as heat noise. Thus, little influence is given to the transmission even if any transmission format is employed.
When the multiplexing scheme is FDM (Frequency Division Multiplex) and TDM (Time Division Multiplex), however, the interference between the cells cannot be identified as heat noise and, therefore, a great influence is given to the transmission. The similar problem occurs even in the OFDM modulation (for example, 3GPP, TS 25.214 V5.11.0 (2005-06), 6A HS-DSCH-related procedures) that has been developed recently since its multiplexing scheme is the FDM or the TDM.
There is a problem that in the radio communication system employing the conventional multi-carrier modulation, a great influence is given to the transmission since the interference between the cells cannot be identified as heat noise.