Intel Corporation

Arizona Board of Regents, a Body Corporate

John S Sadowsky

Alexander A Maltsev

Ali Sadri

Sumeet Sandhu

Eric A Jacobsen

Adrian Paul Stephens

Minnie Ho

Vadim Sergeyevich Sergeyev

Alexei Vladimirovich Davydov

Assaf Yaakov Kasher

Shmuel Levy

Gal Basson

Keith A Holt

Shay Waxman

Jorge Myszne

Shai Waxman

Yuval Finkelstein

Jami J Shah

Ali S Sadri

A wireless device may include processing circuitry that is configured to process a preamble of a packet, the preamble comprising a legacy portion comprising a legacy signal field (L-SIG) and a subsequent portion comprising a non-legacy signal field. The processing circuitry may be further configured to determine whether a symbol of the non-legacy signal field is modulated using binary phase shift keying (BPSK) or modulated using quadrature binary phase shift keying (OBPSK). The processing circuitry may be further configured to process the subsequent portion of the packet in accordance with a first packet format if the symbol of the non-legacy signal field is modulated using OBPSK, and to process the subsequent portion of the packet in accordance with a different packet format if the symbol of the non-legacy signal field is modulated using BPSK.

Method for signaling information by modifying modulation constellations

A wireless device may include processing circuitry that is configured to process a first portion of a packet, the first portion of the packet comprising a legacy signal (L-SIG) field, and determine whether a constellation of a field of a second portion of the packet is binary phase shift keying (BPSK) or quaternary binary phase shift keying (QBPSK). The processing circuitry may be further configured to: process the second portion of the packet in accordance with a packet structure indicated by the constellation.

Methods and systems for communicating in a wireless network may distinguish different types of packet structures by modifying the phase of a modulation constellation, such as a binary phase shift keying (BPSK) constellation, in a signal field. Receiving devices may identify the type of packet structure associated with a transmission or whether the signal field is present by the phase of the modulation constellation used for mapping for the signal field. In one embodiment, the phase of the modulation constellation may be determined by examining the energy of the I and Q components after Fast Fourier Transform. Various specific embodiments and variations are also disclosed.

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.

MIMO transmitter and method for transmitting OFDM symbols

In a multiple-input multiple-output (MIMO) system, multiple receive antennas produce a received signal vector, Y, which includes an element for each of the receive antennas. In an embodiment of a de-mapping method performed within a MIMO receiver, a quadrature phase shift keying (QPSK) search is performed within a search space that includes the full constellation of symbol points. Based on the results of the QPSK search, the search space is reduced to fewer than all of the quadrants, and the received signal vector data is scaled and transformed to the reduced search space. A lower-level QPSK search is performed, and the process is repeated until the modulation order is reduced to a QPSK constellation. Hard or soft decisions corresponding to the search results may then be passed to a decoder.

MIMO receiver and method for receiving spatially-multiplexed OFDM signals

A MIMO transmitter and method for transmitting a group of sequential OFDM symbols on a downlink channel using a plurality of antennas is disclosed herein. Groups of OFDM subcarriers are individually modulated in accordance with spatial-frequency subcarrier modulation assignments to generate groups of symbol-modulated subcarriers, corresponding symbol-modulated subcarriers are combined for transmission on each of a plurality of spatial channels, and beamforming is performed on the combined symbol-modulated subcarriers for transmission over the spatial channels. The 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. The spatial-frequency subcarrier modulation assignments for each group are determined based on feedback by a receiver, which is determined from spatial channel characteristics of the spatial channels.

MIMO transmitter for transmitting a group of sequential OFDM symbols using a plurality of antennas

In a communication system using closed loop multiple input multiple output (MIMO), beam forming information may be fed back from a receiver to a transmitter sequentially over a number of frames. The beam forming matrices that are fed back may be quantized.

Method and apparatus for performing sequential closed loop multiple input multiple output (MIMO)

Symbol de-mapping methods in multiple-input multiple-output systems

OFDM transmitter and method for multi-user MIMO transmissions

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.

MIMO transmitter and method for transmitting a group of sequential OFDM symbols in accordance with an IEEE 802.16 communication standard

Methods and apparatus provide increased symbol length with more subcarriers in a fixed-bandwidth system. The subcarriers spacing may be reduced to provide increased symbol length and enable higher throughput. In one implementation, a system compatible with the IEEE P802.11n proposal can use 128 subcarriers in 20 MHz operation to provide increased throughput in lower-bandwidth channel operation.

Increased discrete point processing in an OFDM communication system

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.

MIMO transmitter and method for transmitting an OFDM symbol in accordance with an IEEE 802.11 communication standard over a plurality of spatial channels

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.

Growing community of inventors

Mesa, AZ, United States of America

John S Sadowsky