摘要:
An orthogonal-frequency division multiplexed (OFDM) transmitter is configured to transmit a data unit in accordance with a multiple-input multiple-output (MIMO) technique over a wideband channel comprising a 20 MHz channel and another channel using a plurality of spatially diverse antennas. The transmitter is further configured to include in the data unit, a parameter indicating a modulation and coding scheme and a parameter indicating number of spatial streams. Each of the spatial streams is encoded and beamformed for receipt by one or more different receiving stations.
摘要:
A multiple-input-multiple output (MIMO) transmitter for transmitting a group of sequential orthogonal frequency division multiplexed (OFDM) symbols on a time-division duplexed (TDD) channel in accordance with an IEEE 802.16 standard using a plurality of antennas. The MIMO transmitter comprises a spatial-frequency parser to parse a block of bits into spatial-frequency blocks of a variable number of coded bits, and subcarrier modulators to individually modulate OFDM subcarriers with the spatial-frequency blocks in accordance with spatial-frequency subcarrier modulation assignments to generate groups of symbol-modulated subcarriers. The TDD channel comprises a plurality of the groups of the OFDM subcarriers, and the OFDM subcarriers within each group of subcarriers and within each group of sequential OFDM symbols have the same spatial-frequency subcarrier modulation assignments.
摘要:
A compensating correction value for adjusting analog signals received from multiple antenna elements takes into account the effects of colored noise, co-channel interference, and inter-sample interference. The method of generating the compensating correction value for analog combining architectures considers the total channel impulse response over a block of time.
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:
A multiple-input-multiple output (MIMO) transmitter for transmitting an orthogonal frequency division multiplexed (OFDM) symbol over a plurality of spatial channels using a plurality of antennas is described. The transmitter includes encoding circuitry to encode blocks of input bits in accordance with a variable encoding rate to generate blocks of encoded bits and a spatial-frequency parser to parse the blocks of encoded bits into spatial-frequency groups. The transmitter also includes subcarrier modulators to modulate each spatial-frequency group of encoded bits on one of the OFDM subcarriers to generate symbol-modulated subcarriers. Spatial-frequency groups having a greater number of encoded bits are modulated at higher-order modulation levels and spatial-frequency groups having a lesser number of encoded bits are modulated at lower-order modulation orders.
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:
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.