摘要:
An embodiment of the present invention provides a method, comprising optimizing the location and configuration of relay stations in a wireless network that includes at least one base station and at least one relay station by taking into account at least one or more of the following: the distinct antenna heights of said at least one base station and said at least one relay station; the data dependency between said at least one relay station and said at least one base station; the service outage of said wireless network; and the network throughput of said wireless network.
摘要:
In Spatial Division Multiple Access (SDMA) communications, mobile devices that are transmitting to a base substantially simultaneously during a predetermined communications phase may wait until after an end of the predetermined communications phase to receive acknowledgments to their transmissions, so that a mobile device making a relatively short transmission does not experience an acknowledgement timeout while another mobile device is still completing a relatively long transmission. In some embodiments, the mobile devices may transmit a non-immediate block acknowledgement request during the communications phase.
摘要:
In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.
摘要:
Embodiments of the present invention provide methods and apparatus for wireless communication using codeword with high-rate codes. Other embodiments may be described and claimed.
摘要:
A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment. Such systems are compatible with bandwidth-on-demand and higher-order modulation formats and use advanced adaptation algorithms. In a specific embodiment the spectral and spatial components of the adaptive weights are calculated in a unified operation based on the mathematical analogy between the spectral and spatial descriptions of the airlink.
摘要:
A multicarrier transmitter may transmit cyclically delayed linear combinations of two or more data streams with three or more antennas. In some embodiments, the multicarrier transmitter may transmit cyclically delayed linear combinations of three data streams with four antennas.
摘要:
During a training phase in a network using spatial division multiple access (SDMA) techniques, frame types that trigger network allocation vectors may be used in the training phase to prevent unwanted devices from transmitting during the training phase.
摘要:
In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.
摘要:
According to some embodiments, a technique is provided that coordinates transmission of frames to reduce collisions. Frames are coordinated according to, for example, operation type, frame length, and solicited response. A base station gains access to a wireless medium and transmits multiple coordinated frames to multiple communication units. The transmissions to the multiple communication units may be substantially simultaneous in that at least a portion of the different frames are transmitted at the same time. The different frames may be substantially back-end aligned where the maximum difference between the termination time instances of the frame transmissions is controlled to reduce collisions.