Field of the Invention
The present invention relates to mobile communication.
Related Art
3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) that is an advancement of UMTS (Universal Mobile Telecommunication System) is being introduced with 3GPP release 8. In 3GPP LTE, OFDMA (orthogonal frequency division multiple access) is used for downlink, and SC-FDMA (single carrier-frequency division multiple access) is used for uplink. The 3GPP LTE adopts MIMO (multiple input multiple output) having maximum four antennas. Recently, a discussion of 3GPP LTE-A (LTE-Advanced) which is the evolution of the 3GPP LTE is in progress.
As set forth in 3GPP TS 36.211 V10.4.0, the physical channels in 3GPP LTE may be classified into data channels such as PDSCH (physical downlink shared channel) and PUSCH (physical uplink shared channel) and control channels such as PDCCH (physical downlink control channel), PCFICH (physical control format indicator channel), PHICH (physical hybrid-ARQ indicator channel) and PUCCH (physical uplink control channel).
Meanwhile, research on communication that is carried out between devices or between a device and a server without any human interaction, i.e., without any human intervention, i.e., machine type communication (MTC) has recently been extensively carried out. MTC refers to a concept of establishing communication between mechanical devices, and not equipments used by humans, by using the conventional wireless communication network.
Since the characteristics of the MTC are different from general user equipments, services that are optimized for the MTC may be different from services that are optimized for human-to-human communication. In comparison with the current Mobile Network Communication Service, the MTC can be characterized as different market scenarios, data communication, lower cost and less effort, a potentially large number of MTC devices, wider service areas, lower traffic per MTC device, and so on.
Recently, enhancing (or extending) the cell coverage of a base station has been considered, and diverse methods for cell coverage extension (or cell coverage enhancement) are being discussed. However, in case the coverage of the cell is extended (or enhanced) if the base station transmits a channel as when performing transmission to a general UE, a MTC device that is located in the cell coverage enhancement region may have difficulty in receiving the transmitted channel.
Additionally, it may be expected that the MTC devices have low performance in order to have its supply rate increased at lower costs. And, in case of transmitting the PDCCH, EPDCCH or PDSCH just as when transmitting to a general user equipment, the MTC device that is located in the cell coverage enhancement region may have difficulty in receiving the transmitted channel.
Additionally, in case the MTC device transmits PUCCH and PUSCH, which correspond to uplink channels, by using a general method, the base station may have difficulty in receiving the transmitted channel from the MTC device, which is located in the cell coverage enhancement region.