| 摘要 |
A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration. |
| 主权项 |
1. A method of transmitting and receiving pilots in a wireless multiple-input multiple-output (MIMO) communication system, comprising:
transmitting a MIMO pilot on a forward channel from a plurality of antennas and on a first communication link via a plurality of transmission channels, wherein the MIMO pilot comprises a plurality of pilot transmissions sent from the plurality of antennas, and wherein the pilot transmission from each antenna is configured to be identifiable by a communicating entity receiving the MIMO pilot; and receiving a steered pilot on a reverse channel via a plurality of eigenmodes of a second communication link from the communicating entity, wherein at least some of the plurality of eigenmodes are used for data transmission, and wherein the steered pilot is generated based on the MIMO pilot and a channel response matrix for the plurality of transmission channels. |
