Patent ID: 8942143
Filing Date: 2015-01-27
Classification: H04B,H04L

Abstract:
1. A time division duplex (TDD) orthogonal frequency division multiplexing (OFDM) distributed antenna system (DAS), the TDD-OFDM DAS using a transmission band comprising a used band subcarrier set and a guard band subcarrier set, the TDD-OFDM DAS comprising: a base station, being configured to perform an inverse fast Fourier transform on a user downlink signal, a transmitting/receiving enable signal and an input control signal to generate a first OFDM signal, the user downlink signal being carried on the used subcarrier set of the first OFDM signal, and the transmitting/receiving enable signal and the input control signal being carried on the guard band subcarrier set of the first OFDM signal; a remote access unit (RAU), being connected to the base station via a fiber transmission line and being configured to receive the first OFDM signal and filter the transmitting/receiving enable signal and the input control signal carried on the guard band subcarrier set of the first OFDM signal to generate a second OFDM signal; wherein the RAU is further configured to retrieve the transmitting/receiving enable signal and the input control signal from the guard band subcarrier set of the first OFDM signal, switch between a transmitting mode and a receiving mode periodically according to the transmitting/receiving enable signal, transmit the second OFDM signal to a user device in the transmitting mode, perform a clock synchronization with the base station according to the transmitting/receiving enable signal, and perform a system configuration according to the input control signal.