Kabushiki Kaisha Toshiba

Toshiba Research Europe Limited

Fengming Cao

Parag Kulkarni

Zhong Fan

Rudzi Dziyauddin

Tsuguhide Aoki

Filippo Tosato

Timothy David Farnham

Yichao Jin

Yong Sun

Mahesh Sooriyabandara

Siva Kupanna Subramani

Sadia Quadri

Ngoc-Dung Dao

Chetan Harsha

Zhenzhe Zhong

Management of receiver sensitivity in a packet based wireless communication system is achieved by controlling a clear channel sensing process which determines if the channel is clear for use, governed by a sensitivity to use of the channel. The sensitivity of the clear channel sensing process is effected by monitoring transmission performance over a plurality of emissions, and making adjustments to the sensitivity based on comparison of that performance with a performance criterion.

Wireless communications device and method

A controller for allocating a radio resource block to a user device in a cell of a cellular network, includes a device for identifying a plurality of edge user devices within range of a first base station, a device for identifying, from the plurality of edge user devices, a first edge user device with which the first base station intends to communicate and a second edge user device presently communicating with a second base station in a neighboring cell, and a device for allocating a communication channel to the first edge user device by assigning a resource block for communications between the first edge user device and first base station. The resource block is one that will provide the highest transmission rate for the first edge user device, while differing from any resource blocks already allocated for communication between the second edge user device and the second base station.

Controller for allocating radio resource blocks to user devices located in cells of a cellular network

A device and method for wirelessly communicating over a transmission channel with one or more wireless devices. The device comprises a wireless network interface and a controller. The controller is configured to receive a wireless signal via the wireless network interface, if strength of the received signal is greater than a first threshold, determine that the channel is busy, and, if the strength of the received signal is not greater than the first threshold, but is greater than a second threshold that is lower than the first threshold, determine whether the received signal is intended for the device and if so, determine that the channel is busy.

Multi-threshold listening method for dynamic sensitivity control enabled wireless MAC

A device and/or method for dynamically adjusting a CCA threshold in an addressable unit that is suitable for communication in a wireless network, the method performed in the addressable unit and comprising autonomously increasing the CCA threshold with successful data transmissions and/or autonomously decreasing the CCA threshold with unsuccessful data transmissions.

Dynamic sensitivity control in 802.11 stations

In a 3GPP LTE-A support for Mobile Type Communications, that is, M2M communications scheme, improvements of the random access are necessary to prevent random channel overload. Enhanced backoff in the presence of overload is such a mechanism, Counting the number of devices seeking RACH based on the number of received random access requests or else responses, and allocating Random Access resources on the basis of the number of requests, is another. Further, a channel aware resource allocation approach provides a way of determining, from the received requests, delay-tolerance of the M2M devices, based on which they are prioritized in accessing the random channel. Even within the prioritized devices, a smaller subset thereof may be prioritized further, according to radio conditions, to provide better access to those with higher SNR RBs.

RAN overload control for M2M communications in LTE networks

In an embodiment, a method of managing resources in a cell cluster of a wireless network is disclosed. The cell cluster comprises a plurality of cells, each cell having an inner region and an outer region. The method comprises: setting, for each cell, a power ratio, the power ratio being the ratio of the power level to be used for transmission of signals to wireless devices located in the inner region of that cell to the power level to be used for transmission of signals to wireless devices located in the outer region of that cell; allocating network resources from a plurality of network resources to wireless devices located in the outer regions; for each cell, allocating network resources to wireless devices located in the inner region of that cell from network resources of the plurality of network resources that are not allocated to wireless devices located in the outer region of that cell; receiving, for each cell, indications of a first data throughput rate for transmission of data to the wireless devices located in the outer regions; comparing, for each cell, the first data throughput rate with a threshold data rate; and decreasing the power ratio for cells in which the first data throughput rate is less than the threshold data rate.

Wireless communication methods and apparatus

A method for allocating communication channels to access points in a communications network comprising: identifying, amongst the access points, one or more interference-prone pairs of access points, wherein each interference-prone pair comprises a first access point and a second access point that are currently using the same or overlapping communication channels to communicate with their respective client user devices, determining the number N of non-overlapping channels that are available for allocating to the access points; allocating the N non-overlapping channels between the access points in such a way as minimize the number of interference-prone pairs of access points; and where an access point cannot be allocated any one of the N channels without it comprising part of an interference-prone pair, selecting a particular one of the N channels to allocate to the access point based on a selection criterion.

Method for allocating communication channels to access points in a communications network

In one embodiment a method of identifying interference in a wireless network is disclosed. The wireless network comprises a first base station and a second base station. The method comprises detecting an increase in an error rate in a wireless connection between the first base station and a first wireless device; comparing a reference signal power received by the first wireless device from the first base station with a threshold value; and determining that the increase in error rate is due to interference from a wireless connection between the second base station and a second wireless device if the reference signal power is greater than the threshold.

Allocation of terminal stations to communications channels is carried out on the basis of a selection criterion. Allocation takes account of whether the terminal station is in an edge region of a cell. If so, then the list of terminal stations to be allocated is modified, to account for any interference risk from other base stations.

Inter-cell interference mitigation

In a network comprising user devices and signal notes, communication links are scheduled by identifying one or more active signal node/user device pairs, wherein each active pair comprises a signal node that is presently communicating with a respective active user device over a signal channel. Then, one or more inactive signal node/user device pairs is identified; each inactive pair comprises an inactive signal node that is not presently communicating over the signal channel and a potential user device that is capable of communicating with the inactive signal node over the signal channel. One of the inactive pairs is then identified which, when made into an active pair, will achieve the greatest total fairness criterion, the total fairness criterion being a sum of a fairness criterion for the potential user device in the inactive pair in question and a fairness criterion for each of the active user devices in the event that the respective inactive pair becomes an active pair. The fairness criterion for each user device is dependent on the transmission rate achievable between the user device and the signal node in its respective pair.

Radio resource management for distributed cellular systems

According to one embodiment there is provided a method performed in a transmitter side of a multiuser minimum square error linear precoding MIMO system that comprises a transmitter with a plurality of transmit antennae and a plurality of receivers. Each receiver of the plurality of receivers comprises a plurality of receive antennae. The method is a method of scheduling receivers from among the plurality of receivers and comprises obtaining, for some or all of the receivers, receiver channel information that quantifies the properties of transmit channels between receiver antennae of the receiver and transmit antennae of the transmitter and establishing an order for determining the receiver combining vectors of the some or all of the receivers. The order is established by selecting as a next receiver in the order a so far unselected receiver from the some or all of the receivers that minimally increases the mean square data transmission error. The establishing of the order is based on the channel information of any receivers previously selected in the order and of unselected receivers.

Linear multiuser precoding with multiple-receive antenna receivers

According to one embodiment there is provided a method of determining receiver beam forming vectors for a plurality of receivers in a MIMO system. Each receiver comprises a plurality of receiver antennae. The MIMO system also comprises a plurality of transmitter antennae. The method comprises quantifying the properties of the channels of the MIMO system in a channel property matrix including interference between individual channels and performing Cholesky decomposition of the receiver property matrix row-by-row into a lower triangular matrix with unit elements along its diagonal, a diagonal matrix and the Hermitian transpose of said triangular matrix. Performing the Cholesky decomposition comprises determining, when performing a step of the Cholesky decomposition for a row, a receiver-beam forming vector associated with the row that maximises the component of the diagonal matrix in the row.

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Bristol, United Kingdom

Fengming Cao