| 摘要 |
This invention relates to apparatus, methods, processor control code and signals for channel estimation in OFDM (Orthogonal Frequency Division Multiplexed) communication systems with a plurality of transmitter antennas, such as MIMO (Multiple-input Multiple-output) OFDM systems. A method of generating an OFDM signal for transmission from an OFDM transmitter using a plurality of transmit antennas is provided, the OFDM signal being adapted for channel estimation for channels associated with said transmit antennas by the inclusion of training sequence data in the signal from each said antenna wherein one or more sub-carriers are null, the method comprising the step of deriving said training sequence data by numerical optimisation of a channel estimate. The optimisation involves deriving a cost functions to establish the minimum mean squared error (MSE) metric. The optimisation is performed using a gradient descent process, preferably an interior point method such as the primal dual or barrier methods. |
