Mitsubishi Electric Research Laboratories, Inc.

Mitsubishi Electric Corporation

Daqing Gu

Jinyun Zhang

Andreas F Molisch

Hongyuan Zhang

Zhifeng Tao

Yuan Yuan

Jianxuan Du

Philip Orlik

Ye Li

Dong Wang

Yukimasa Nagai

Chia Shen

Jay Bao

Hisashi Kobayashi

Stuart C Schwartz

Juntan Zhang

Huai-Rong Shao

Phillip Orlik

Lei Cao

Xiaoqiang Ma

A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets, and a subset of antennas is selected according to the channel matrix.

Training signals for selecting antennas and beams in MIMO wireless LANs

A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets. A frame including a high throughput (HT) control field is sent to initiate a selecting of antennas, and a subset of antennas is selected according to the channel matrix.

Method for selecting antennas and beams in MIMO wireless LANs

A method selects antennas in a multiple-input, multiple-output (MIMO) wireless local area network (WLAN) that includes a plurality of stations, and each station includes a set of antennas. Plural consecutive packets, received at a station, include plural consecutive sounding packets. Each sounding packet corresponds to a different subset of the set of antennas, and at least one of the plural consecutive packets includes a high throughput (HT) control field including a signal to initiate antenna selection and a number N indicative of a number of sounding packets which follow the at least one packet including the HT control field and which are to be used for antenna selection. A channel matrix is estimated based on a characteristic of the channel as indicated by the received N sounding packets, and a subset of antennas is selected according to the channel matrix. Station and computer program product embodiments include similar features.

Antenna/beam selection training in MIMO wireless LANS with different sounding frames

A method for selecting antennas in a multiple-input, multiple-output wireless communications network that includes multiple stations is presented. Each station includes a set of transmit RF chains and a set of receive RF chains, and each RF chain is connectable to a set of antennas. A first station transmits a training frame for each possible subset of the set of antennas, and the set of transmit RF chains are connected to the subset of antennas according to a connection mapping rule while transmitting each training frame. A subchannel matrix is estimated in a second station for each frame. The subchannel matrices are combined to obtain a complete channel matrix. A particular subset of the antennas is selected according to the complete channel matrix. The set of transmit RF chains is connected to the selected particular subset of antennas to transmit data from the first station to the second station.

Antenna selection with RF imbalance

A method for decoding error-correcting codes normalizes messages generated by a bit node processor, and normalizes messages generated by the check node processor.

2D-normalized min-sum decoding for ECC codes

A method transmits 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 Nantennas and NRF chains and the station B includes Nantennas and NRF chains, and a number of frames in the long sequence of training frames is at least equal to where is a lower bound operator. 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. A number of frames in the short training sequence is at least equal to 

Training frames for MIMO stations

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.

Frame aggregation in wireless communications networks

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.

Scheduling packet flows in multi-rate wireless local area networks

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.

Access control and protocol for packet switched wireless communications networks

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.

Method for acknowledging data packets in a network

A method minimizes a rate for feeding back channel state information from a receiver to a transmitter in a multi-input, multi-output communications systems. A temporal autocorrelation function of the channel between the transmitter and the receiver is determined. A spatial covariance information is estimated of the channel. Then, the minimum rate for feeding back channel state information from the receiver to the transmitter is based on actual channel state information and the estimated spatial covariance information and the temporal autocorrelation function.

Minimizing feedback rate for channel state information in MIMO systems

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.

Dynamic resource control for high-speed downlink packet access wireless channels

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.

Signaling in a wireless network with sequential coordinated channel access

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.

Passive and distributed admission control method for ad hoc networks

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.

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Burlington, MA, United States of America

Daqing Gu