MIMO OFDM System
AssigneeAT&T Intellectual Property II, L.P.
InventorsYe Li, Nelson Ray Sollenberger, Jack Harriman Winters
Life of this patent
Estimating the term…
Abstract
A MIMO OFDM system includes a plurality of space-time encoders for encoding respective data blocks with independent space-time codes. The transformed data block signals are transmitted by a plurality of transmit antennas and received by a plurality of receive antennas. The received data is pre-whitened prior to maximum likelihood detection. In one embodiment, successive interference cancellation can be sued to improve system performance. Channel parameter estimation can be enhanced by weighting the channel impulse response estimates based upon a deviation from average.
Claims4
A receiver constructed to receive signals from a remote unit that at time n transmits a data block b1[n,k] over two transmit antennas and transmits a data block b2[n,k] over two other transmit antennas, where k=0, 1, 2, . . . , comprising
- N receive antennas, each receiving a signal that includes signals related to the signals transmitted by the transmit antennas of the remote unit, where N is equal or greater than 4;
- N FFT modules, each coupled to an associated one of said receive antennas;
- a space-time processing (STP) unit, responsive to said FFT modules, which pre-whitens signals applied by said STP unit and performs maximum likelihood detection on each of the pre-whitened signals, and which, when initially detecting data pertaining to block b1[n,k] treats other received signals, including signals received from the antennas that transmit data pertaining to block b2[n,k], as interfering noise, and when initially detecting data pertaining to block b2[n,k] treats other received signals, including signals received from the antennas that transmit data pertaining to block b1[n,k], as interfering noise;
- a first space-time decoder responsive to output signals of said STP unit for decoding block b1[n,k];
- a second space-time decoder responsive to output signals of said STP unit for decoding block b2[n,k];
- and
- a channel parameter estimator responsive to output signals of said FFT modules and output signals of said space-time decoders, for developing parameter estimates of channel between the remote unit and the receiver, and applying the developed estimates to said space-time decoders.
Dependencies are inferred from the claim text.