摘要:
A transmitter that is operable to transmit data to a receiver across a wireless link, the transmitter comprising: an antenna, a radio frequency unit communicatively coupled to the antenna, and at least one digital processor coupled to the radio frequency unit. The digital processor being operable to cause the transmitter to pass link layer packet data from a link layer operating thereon to a physical layer operating thereon, package the link layer packet data into physical layer data, transmit the physical layer data to the receiver, await an indication of successful receipt of the physical layer data from the receiver for a delay period, when an indication of successful receipt of the physical layer data is not received during the delay period, initiate retransmission of the physical layer frame, when a negative acknowledgement is received during the delay period retransmitting the physical layer frame, if the indication of successful receipt of the physical layer data is not received after at least one retransmission attempt, notify the link layer that the packet data unit is lost; and cause the link layer to initiate error recovery operations for link layer packet data.
摘要:
A terminal apparatus for use with an orthogonal frequency division-multiplexing (OFDM) system that uses a multiple input multiple output (MIMO) structure, the teminal apparatus comprising: a controller that responds to receipt of an OFDM signal by making a determination as to whether subsequent MIMO OFDM signals should be transmitted independently of each other or corresponding to each other and causing a feedback signal to be transmitted indicative of that determination. The determination for the subsequent transmissions includes a determination as to whether transmit diversity or spatial multiplexing should be used and the feedback signal is indicative of that determination.
摘要:
An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.