Abstract: A method transmits transmitting training frames in a MIMO system. A long sequence of training frames is transmitted from a station B to a station A via a channel of the MIMO system, in which the station A includes NA antennas and N—SS RF chains and the station B includes NB antennas and NB—SS RF chains, and a number of frames in the long sequence of training frames is at least equal to A short sequence of training frames is transmitted from the station A to the station B via the channel in response to receiving the long sequence of training frames.

Abstract: A method and system accesses a wireless channel in a communications network including multiple stations and an access point connected by the wireless channel. The access point periodically broadcasts polling information indicating when a station can transmit. A next station is polled in an acknowledgement message broadcast by the access point in response to receiving data transmitted by a previously polled station.

Abstract: A system and method detect symbols of a modulated signal received via a plurality of channels of a wireless communications system. A symbol transmitted via the channels is initially estimated based on the channel estimate from either pilot symbol or previously estimated symbol, and then channel estimate is updated. The next estimate of the symbol is computed by using updated channel information and maximizing the expectation of the log likelihood function. The next estimate is then quantized according to the signal constellation. The quantized estimate of the symbol is compared with the previous estimate of the symbol to determine if the previous estimate of the symbol and the quantized next estimate of the symbol have converged. Otherwise, the quantized next estimate of the symbol is made as the input for the next iteration, and the updating, optimizing, quantizing, and comparing are repeated until the estimate converges.

Abstract: A method and system performs blind joint channel estimation and signal detection in a communication system that includes multiple channels for transmitting symbols. The multiple channels are estimated using a small number of symbols initially received through the multiple channels. When the channels have been estimated, a single best channel is selected. From then on, the bulk of the symbols are detected only on the best channel, while the best channel is updated.

Abstract: A method aggregates frames to be transmitted over a channel in a wireless network into a single frame. Multiple MSDU frames having identical destination addresses and identical traffic classes, received in the media access control layer from the logical link layer in a transmitting station are aggregated into a single aggregate MPDU frame, which can be transmitted on the channel to a receiving station. In addition, aggregate MSDU frames with different destination addresses and different traffic classes received from the media access control layer can be further aggregated into a single aggregate PPDU frame before transmission.

Abstract: A method signals data in a channel of a network including multiple stations and an access point connected by a wireless channel. A station first requests access to the channel using a sequential coordinated channel access method of an access point. After the station receives permission to access the channel during a contention free period at a time corresponding to a sequence index value received by the station from the access point, the station transmits a resource request message to the access point to obtain a bandwidth allocation. In response, the station receives the bandwidth allocation, and the station can then transmit data during the contention free period according to the bandwidth allocation.

Abstract: A method selectively acknowledges data packets in a network including a multiple stations connected by a common wireless channel. A transmitting station requests a block acknowledgement from a receiving station. The transmitting station transmits a block of data packets to the receiving station. The receiving station determines a number of successfully received data packets and a number of incorrectly received packets. Then, the receiving station selectively acknowledges only the successfully received data packets if the number of usefully received data packets is less than the number of incorrectly received data packets, and otherwise acknowledging only the incorrectly received packets.

Abstract: A method provides access to a channel in a network including stations and an access point connected by a common wireless channel. A station makes a request to the access point to access to the channel to transmit a data stream. The access point assigns a sequence index value to the data stream. The sequence index value is broadcast by the access point. Then, the station transmits the data stream, during a contention free period, at a time corresponding to the sequence index value.

Abstract: A method transmits packets over a single channel in a wireless communication network that includes multiple nodes. Access to the channel is gained in a transmitting node. Then, a block of packets is transmitted to a receiving node via the channel. The transmitting node receives only a single acknowledgement packet from the receiving node in response to transmitting the block of packets.

Abstract: A method codes multiple data streams in multiple-input, multiple-output communications systems. In a transmitter, an input bitstream is encoded as codewords b in multiple layers. Each layer is modulated. A quasi-block diagonal, low-density parity-check code is applied to each layer, the quasi-block diagonal, parity-check code being a matrix H, the matrix H including one row of blocks for each subcode, and one row of blocks for each layer such that Hb=0 for any valid codeword. The layers are then forwarded to transmit antennas as a transmitted signal x.

Abstract: A system and method schedule series of packets for transmission between terminals in a single wireless channel of a packet-switched local area network. The local area network can operate in an ad hoc mode or in infrastructure mode. A transmission rate is assigned to each of the terminals. The terminals can be mobile. Different terminals can be assigned different transmission rates, depending on a quality of the channel. That is, terminals transmitting via an error-free channel are assigned a higher transmission rate than terminals transmitting via an error-prone channel. Then, the series of packets are scheduled for transmission between the terminals such that each terminal receives a substantially equal amount of transmission time over an extended period of time.

Abstract: A method for distributed admission control in communication channels of a network including a plurality of nodes measures, at each node, a traffic condition of a communication channel during successive time intervals having a predetermined length. At the particular node, the measured traffic condition for a last time interval is compared to a threshold. The state of the node is changed depending on the comparing.

Abstract: A digital transceiver system includes a downlink channel and an uplink channel. In the system, a transmitter transmits signals on the downlink channel and receives signals on the uplink channel. The transmitter includes a pre-coder having a plurality of filters. Each filter has a corresponding filter coefficient. The transmitter also includes a filter coefficient updater coupled to the pre-coder. A receiver of the system receives signals on the downlink channel and transmits signals on the uplink channel. The receiver includes linear equalizers having a plurality of taps. Each tap has a corresponding tap coefficient. The coefficient updater is configured to dynamically update the filter coefficients according to the tap coefficients which are indicative of the frequency response of the receiver.

Abstract: A method allocates resources of a wireless communications network to traffic transmitted to user equipment over a channel of the network. A packet of the traffic to be stored in a selected queue is received. A maximum delay of the selected queue is determined, along with a start time, a finish time, and a queuing order. The packet is inserted in the selected queue according to the start time, the finish time and the queuing order, and then a weight of the selected queue is updated. Then, a next packet to be dequeued from the selected queue is scheduled, and the next packet is transmitted to the user equipment over the channel.

Abstract: A system and method detect symbols of a modulated signal received via a plurality of channels of a wireless communications system. A symbol transmitted via the channels is initially estimated based on the channel estimate from either pilot symbol or previously estimated symbol, and then channel estimate is updated. The next estimate of the symbol is computed by using updated channel information and maximizing the expectation of the log likelihood function. The next estimate is then quantized according to the signal constellation. The quantized estimate of the symbol is compared with the previous estimate of the symbol to determine if the previous estimate of the symbol and the quantized next estimate of the symbol have converged. Otherwise, the quantized next estimate of the symbol is made as the input for the next iteration, and the updating, optimizing, quantizing, and comparing are repeated until the estimate converges.

Abstract: A method and system performs blind joint channel estimation and signal detection in a communication system that includes multiple channels for transmitting symbols. The multiple channels are estimated using a small number of symbols initially received through the multiple channels. When the channels have been estimated, a single best channel is selected. From then on, the bulk of the symbols are detected only on the best channel, while the best channel is updated.