Abstract: A method for controlling a sleep mode operation by a mobile station (MS) in a communication system. In the sleep mode operation control method, after entering a sleep mode, the MS transitions to an awake state in a listening interval. When there is data to transmit or receive to/from a base station (BS) in the awake state, the MS causes a neutral interval following the listening interval to transition to the awake state, and transmits or receives the data. The neutral interval is an interval where transition to the awake state and sleep state is available according to the data transmission/reception of the MS operating in the sleep mode.

Abstract: A method for controlling a sleep mode operation by a mobile station (MS) in a communication system. In the sleep mode operation control method, after entering a sleep mode, the MS transitions to an awake state in a listening interval. When there is data to transmit or receive to/from a base station (BS) in the awake state, the MS causes a neutral interval following the listening interval to transition to the awake state, and transmits or receives the data. The neutral interval is an interval where transition to the awake state and sleep state is available according to the data transmission/reception of the MS operating in the sleep mode.

Abstract: A receiver for a hybrid space time block codes (STBC) scheme using a nonlinear decision feedback (DFB) filter instead of a conventional linear filter which are used in the hybrid STBC scheme, that is, a combination of a spatial division multiplexing (SDM) scheme and a STBC scheme. In the receiver used for the STBC scheme, a previous-stage remaining signal is detected by using a well-known BLAST algorithm, and inter-symbol interference (ISI) is minimized by applying the previous-stage remaining signal to a current-stage signal, providing improved performance. The receiver used for the STBC scheme can be applied to a time varying channel fading environment as well as a quasi-static channel environment. According to the hybrid STBC scheme, a gain of about 3 dB can be obtained in channel environments having a frame error rate (FER) frequency efficiency of 2 and 3 Bps/Hz in the same condition by using a simulation.

Abstract: The present invention provide a space time block codes (STBC) scheme, where a received signal is filtered by using a minimum mean square error (MMSE) filter, and where channel symbols are individually decoded and converted into bit information, so that an mean square error (MSE) can be minimized by using a linear superposition form applicable to the non quasi-static channel environment as well as a quasi-static channel environment. The present invention provides an STBC scheme using a MMSE filter obtained in a real linear representation method, so that transmitted data can be recovered without loss thereof even in a case where a speed of a mobile station is high.