摘要:
Methods and devices are provided for MIMO OFDM transmitter and receivers having odd and/even numbers of transmit antennas. Various methods for pre-coding information bits before space time coding (STC) are described for enabling transmission of information bits over all antennas. Methods of decoding received signals that have been pre-coded and STC coded are also provided by embodiments of the invention. Pilot patterns for downlink and uplink transmission between a base station and one or more wireless terminals for three transmit antenna transmitters are also provided. Variable rate codes are provided that combine various fixed rate codes in a manner that results in codes whose rates are dependent on all the various fixed rate codes that are combined.
摘要:
A method and system for identifying cell clusters within a coordinated multiple point wireless transmission network in order to reduce scheduling complexity while optimizing throughout and performance. The network includes a total number of cells served by corresponding base stations. The BSC divides the entire network of cells into clusters of cells and forwards this clustering information to all mobile devices. A cluster of cell candidates is a subset of the total number of cells within the network. The mobile device then provides to a base station controller the identity of a cluster of preferred cells selected from the cluster of cell candidates. The base station controller selects at least one base station located within the cluster of preferred cells to establish communication with the mobile device. A wireless connection is then established between the selected at least one base station and the mobile device.
摘要:
A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.
摘要:
A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.
摘要:
A full-duplex transceiver is provided with componentry and methods for cancellation of nonlinear self-interference signals. The transceiver is capable of receiving an incoming radio-frequency signal that includes both a desired radio-frequency signal component and a self-interference component caused by the transceiver's own radio-frequency transmission. The transceiver demodulates the incoming radio-frequency signal to generate a first demodulated signal. The transceiver combines an analog corrective signal with the first demodulated signal to generate a second demodulated signal with reduced self-interference. The transceiver processes the first and second demodulated signals to determine a desired incoming baseband signal and to determine nonlinear components of the self-interference signal, such as nonlinearities introduced by the transceiver's power amplifier.
摘要:
A diversity channel for data transmission is obtained by communication equipment. The diversity channel indicates communication resources that are assigned to the communication equipment, and is from a set of diversity channels that are consistent with codewords of a linear code. The communication equipment also transmits a data transmission using the communication resources indicated by the diversity channel. The diversity channel assignment could be determined, by network equipment for example, and information that identifies the diversity channel could be transmitting to the communication equipment. Such information could be explicitly or implicitly signaled to the communication equipment. A set of diversity channels could be generated directly as codewords of one or more linear codes, or additional operations could be applied to such codewords, and possibly other information that is not generated using a code, to provide a diversity channel set.
摘要:
Embodiments include a method for secure data storage including constructing an encryption key from a plurality of key elements, the constructing including distributing the plurality of key elements to a plurality of key maintenance entities, each of the plurality of key maintenance entities employing a plurality of independent safe guards for their respective key elements of the plurality of key elements; and requiring access to the plurality of key elements to construct the encryption key. The method includes receiving a subset of the plurality of key elements via a twice-encrypted communications channel; and regenerating the encryption key at the client node; and after encrypting data, deleting the subset of the plurality of key elements received over the twice-encrypted communications channel, retaining any of the plurality of key elements previously stored at the client node.
摘要:
An apparatus includes a first transceiver, at least two antennas coupled to the first transceiver to exchange one or more keys and phase data with a second transceiver via a plurality of rounds of phase data exchange, each round including: a first pilot signal sent from a first of the antennas of the first transceiver to the second transceiver, a second pilot signal received from the second transceiver, the second pilot signal modulated using a measured first phase of the first pilot signal, a third pilot signal received from the second transceiver; a fourth pilot signal sent from a second of the antennas of the first transceiver to the second transceiver, the fourth pilot signal modulated using a measured second phase of the third pilot signal, and wherein between the plurality of rounds of phase exchange, the first transceiver perturbs a radio frequency (RF) environment surrounding the at least two antennas.
摘要:
A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.
摘要:
A full-duplex transceiver is provided with componentry and methods for cancellation of nonlinear self-interference signals. The transceiver is capable of receiving an incoming radio-frequency signal that includes both a desired radio-frequency signal component and a self-interference component caused by the transceiver's own radio-frequency transmission. The transceiver demodulates the incoming radio-frequency signal to generate a first demodulated signal. The transceiver combines an analog corrective signal with the first demodulated signal to generate a second demodulated signal with reduced self-interference. The transceiver processes the first and second demodulated signals to determine a desired incoming baseband signal and to determine nonlinear components of the self-interference signal, such as nonlinearities introduced by the transceiver's power amplifier.