Method and apparatus for transmitting data in a time division duplexed (TDD) communication system

A transmitter unit in a time division duplexed (TDD) communication system, comprising:

• a receiver processor operative to receive via a communication link a first transmission from a receiver unit and to estimate characteristics of the communication link based on the received first transmission;
• a transmit data processor operative to code and modulate data based on one or more coding and modulation schemes to provide modulation symbols;
• a controller operative to derive a calibration function indicative of a difference between a first transfer function for a data transmission from the transmitter unit to the receiver unit and a second transfer function for a data transmission from the receiver unit to the transmitter unit;
• a transmit channel processor operative to receive and precondition the modulation symbols based on weights derived at least in part from the estimated characteristics of the communication link and on the calibration function;
• and
• a modulator operative to receive, condition, and transmit the preconditioned modulation symbols via the communication link to the receiver unit.

A receiver unit in a time division duplexed (TDD) communication system, comprising:

• one or more antennas, each antenna configured to receive via a communication link one or more modulated signals transmitted from a transmitter unit;
• one or more front-end units, each front-end unit operative to process a signal from an associated antenna to provide a respective stream of received modulation symbols;
• a spatial processor operative to receive and process the one or more streams of received modulation symbols to provide estimated characteristics of the communication link and to further process the received modulation symbols based at least in part on the estimated characteristics of the communication link to provide one or more streams of recovered modulation symbols an further operative to match filter the received modulation symbols based on a channel response matrix indicative of the estimated characteristics of the communication link and to multiply the filtered modulation symbols with a eigenvector matrix to provide the recovered modulation symbols;
• and
• a receive data processor operative to receive and decode the one or more streams of recovered modulation symbols to provide one or more decoded data streams.

A method for transmitting data from a transmitter unit over a wireless connaunication link to a receiver unit, the method comprising:

• deriving a calibration function indicative of a difference between a data transmission from the transmitter unit to the receiver u-nit and a data transmission from the receiver unit to the transmitter unit;
• receiving via the communication link a first transmission from the receiver unit;
• estimating characteristics of the communication link based on the received first transmission;
• generating modulation symbols for transmission to the receiver unit;
• applying weights to the modulation symbols, the weights being derived from the estimated characteristics of the communication link and the calibration function;
• and
• transmitting the modulation symbols with weights applied from the transmitter unit via the communication link to the receiver unit.

A transmitter unit in a time division duplexed (TDD) communication system, comprising:

• a receiver processor operative to receive via a communication link a first transmission from a receiver unit and to estimate characteristics of the communication link based on the received first transmission;
• a transmit data processor operative to code and modulate data based on one or more coding and modulation schemes to provide modulation symbols;
• a controller operative to derive a calibration function indicative of a difference between a data transmission from the transmitter unit to the receiver unit and a data transmission from the receiver unit to the transmitter unit;
• a transmit channel processor operative to receive and precondition the modulation symbols based on weights derived at least in part from the estimated characteristics of the communication link and on the calibration function;
• and
• a modulator operative to receive, condition, and transmit the preconditioned modulation symbols via the communication link to the receiver unit.