TRANSMITTER AND METHOD OF TRANSMITTING PAYLOAD DATA, RECEIVER AND METHOD OF RECEIVING PAYLOAD DATA IN AN OFDM SYSTEM

摘要

A transmitter transmits payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols. The transmitter comprises a frame builder configured to receive the payload data to be transmitted and to receive signalling data for use in detecting and recovering the payload data at a receiver, and to form the payload data and the signalling data into frames for transmission. The signalling data forms a first of the frames and the payload data forms one or more other frames. A modulator is configured to modulate a first OFDM symbol with the signalling data forming the first frame and to modulate one or more second OFDM symbols with the payload data forming the one or more other frames, and a transmission unit transmits the first and second OFDM symbols. The first OFDM symbol which carries the signalling data is combined before transmission with a signature sequence. The signature sequence can be configured to allow for detection of the first OFDM symbol at the receiver and for decoding of the signalling data before the one or more second OFDM symbols carrying the payload data and at lower signal to noise ratios.