A satellite communication system for enterprise Intranets must be able to support simultaneous multi-point connections among dispersed locations and to allocate satellite channels with the required data rates of each of the connections independently. To meet these requirements, the Multicarrier/Multirate Group Modem (MCMRM) for earth stations is proposed that can process multiple and various rate. MCMRM has the following features. 1. Supports simultaneous communications with hundreds of channels. (Maximum 768) 2. The prototype modem is roughly the same size of as the conventional single carrier modem. 3. To secure flexibility and scalability, the developed modem consists of independent modules. 4. Supports the allocation of bandwidth required over dispersed frequency bands, even if continuous frequency band is not available. MCMRM consists of a multi-rate filter bank and a group modem implemented on several FPGAs controlled by a timesharing system. Evaluations show that MCMRM has even higher BER performance than a conventional single carrier modem. This paper describes the architecture and processing method of MCMRM and performance evaluation results.