A Synchronous Digital Duplexing Technique for Wireless Transmission in Indoor Environments

In this paper, we propose a new digital duplexing scheme, called synchronous digital duplexing (SDD), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously in wireless communication. In order to transmit uplink and downlink signals simultaneously, the proposed SDD obtains mutual information among subscriber stations (SSs) with a mutual ranging symbol. This information is used for selection of transmission time, decision on cyclic suffix (CS) insertion, determination of CS length, and re-establishment of FFT starting point. It is shown that in terms of efficiency and flexibility the proposed SDD is better equipped as a duplexing scheme for indoor wireless environments than conventional time division duplexing (TDD) and frequency division duplexing (FDD).