Patent ID: 7310304
Filing Date: 2007-12-18
Classification: H04B,H04L

Abstract:
1. A transmitter in an Orthogonal Frequency Division Multiplexing (OFDM) system, the transmitter comprising: an encoder configured to process data to be transmitted within the OFDM system, the encoder further configured to separate the data onto one or more transmit diversity branches (TDBs); one or more OFDM modulators, each OFDM modulator connected to a respective TDB, each OFDM modulator configured to produce a frame including a plurality of data symbols, a training structure, and cyclic prefixes inserted among the data symbols; and one or more transmitting antennas in communication with the one or more OFDM modulators, respectively, each transmitting antenna configured to transmit the respective frame over a channel; wherein the training structure of each frame includes a predetermined signal transmission matrix at a respective sub-channel, each training structure adjusted to have a substantially constant amplitude in a time domain, and the cyclic prefixes are further inserted within the training symbol, and wherein the cyclic prefixes within the training symbol are longer than the cyclic prefixes among the data symbols, thereby countering an extended channel impulse response and improving synchronization performance.