摘要:
Systems and methods are provided for transmitting information between an intended source and a receiver to minimize co-channel interference from at least one interfering source. Pilot subcarriers and data subcarriers may be broadcast from an intended source arid at least one interfering source. The pilot subcarriers may be shared across base stations or distributed among base stations in frequency, in time, or both. In addition, the frequency reuse factor of the pilot subcarriers may be different than the frequency reuse factor of the data subcarriers. A receiver receives a composite signal that corresponds with an intended signal from an intended source and an interfering signal from at least one interfering source. The portion of the received signal that corresponds to the intended signal may be recovered by the receiver based on the broadcast of the pilot subcarriers.
摘要:
A plurality of different orthogonal frequency division multiplexing (OFDM) sub-channel blocks are assigned to a plurality of devices including a first device and a second device. The plurality of OFDM sub-channel blocks includes a first OFDM sub-channel block assigned to the first device and a second OFDM sub-channel block assigned to the second device. Data for the first device and data for the second device are received. OFDM data units are generated, wherein data for the first device is modulated on sub-channels in the first OFDM sub-channel block and data for the second device is modulated on sub-channels in the second OFDM sub-channel block. At least one of the OFDM sub-channel blocks is formatted to substantially conform to a physical layer specification of a WLAN communication protocol having a maximum channel bandwidth smaller than a bandwidth of the generated OFDM data units.
摘要:
In a method for transmitting control signals in a multicast communication system, wherein the multicast communication system broadcasts one or more multicast channels, one or more occurrences of a first control signal are transmitted. The first control signal includes at least control information corresponding to the one or more multicast channels. Additionally, one or more occurrences of a second control signal are transmitted for each of the one or more multicast channels. The second control signal includes at least control information corresponding to the respective multicast channel. At least one transmission of an occurrence of the second control signal is synchronized with at least one transmission of an occurrence of the first control signal.
摘要:
Methods and apparatus are provided for directing a beam towards a receiving device in the presence of interference. A beam transmitted by a transmission source is received by a received device. The beam shape is affected by signals transmitted by interfering sources. The receiving device computes channel estimates associated with the transmission source and the interfering sources. A feedback signal that represents the channel estimates associated with the transmission and interfering sources is transmitted to the transmission source. The transmission source changes characteristics of the beam to compensate for the interference caused by the interfering sources. The transmission source may change the characteristics of the beam by performing precoding algorithms.
摘要:
Methods and apparatus for data synchronization in communication systems using repetitive preamble patterns. In one embodiment, a method includes receiving a signal, where the received signal includes a data unit. The data unit includes a preamble symbol, and the preamble symbol has a start time and includes Q portions, each having the same pattern. The method further includes determining multiple possible values of a frame timing (FT). The method further includes determining multiple correlation functions including at least one correlation function corresponding to each of the multiple possible values of the FT, such that a given correlation function corresponding to a given possible value of the FT represents a correlation between data in two non-adjacent portions of the Q portions associated with the given FT. The method further includes selecting one of the multiple possible values of the FT based at least in part on the multiple determined correlation functions.
摘要:
Methods and apparatus are provided for adaptively selecting a communications mode in high frequency systems. A first dual-mode device having capabilities of using two or more high frequency communications modes, such as OFDM and SC modulation, may transmit a signal to a second dual-mode device with the same capabilities. The second dual-mode device may compute a channel characteristic associated with a high frequency communications channel and select an optimal high frequency communications mode. The second dual-mode device may transmit information indicative of the channel characteristic or the selected communications mode to the first dual-mode device. The first dual-mode device may select and operate using the optimal high frequency communications mode based on the information received from the second dual-mode device. The first and second dual-mode devices may communicate using the selected high frequency communications mode.
摘要:
Apparatus having corresponding methods and computer-readable media comprise: a first transceiver comprising a controller configured to select one of a plurality of frequency regions, and a transmitter configured to transmit, according to a first protocol, first wireless signals in the one of the plurality of the frequency regions selected by the controller, wherein each frequency region is characterized by a respective type of unwanted interference generated responsive to the transmitter transmitting the first wireless signals in the respective frequency region; an arbiter configured to select one or more frequency channels based on the one of the plurality of the frequency regions selected by the controller; and a second transceiver configured to transceive, according to a second protocol, second wireless signals only in the one or more frequency channels selected by the arbiter.
摘要:
Systems, methods, and other embodiments associated with phase-rotated tone-grouping modulation are described. According to one embodiment, an apparatus includes a parser configured to reposition bits of at least a portion of a data word. An encoder configured to, from the repositioned bits, form i) a tone grouping and ii) a copy of the tone grouping. The apparatus also includes a modulator configured to modulate the tone grouping and the copy of the tone grouping.
摘要:
A method of mitigating interference from a transmitter of a communication device at a receiver of the same communication device, where the communication device operates according to at least a first and a second communication protocol, includes generating, in the transmitter, a transmit signal conforming to the second communication protocol, generating an interference estimate signal from the transmit signal using an adaptive filter, and receiving a receive signal at the receiver. The receive signal includes a desired component conforming to the first communication protocol and an interference component corresponding to the transmit signal. The method also includes processing the receive signal using the interference estimate signal to remove at least a portion of the interference component from the receive signal.
摘要:
A physical layer module includes a mapping module and a plurality of gain modules. The mapping module maps a plurality of coded data streams to a plurality of transmit antennas, in which each transmit antenna is associated with a respective radio frequency channel of a plurality of radio frequency channels. Each gain module is associated with a respective radio frequency channel of the plurality of radio frequency channels, and is configured to apply a complex gain to the coded data stream mapped to the respective radio frequency channel associated with the gain module. The complex gain applied by the gain module differs relative to that applied by other gain modules, and corresponds to the transmit antenna associated with the respective radio frequency channel.