Marvell International Limited

Quantenna Communications, Inc.

Applied Micro Circuits Corporation

Leland Stanford Junior University

Kathrein-werke Kg

Metawave Communications Corporation

Ravi Narasimhan

Hemanth Sampath

Hsiao-Cheng Tang

Andrea Goldsmith

Shi Cheng

Kedar Shirali

Sam Heidari

Yungping Hsu

Atul Salhotra

Shimon B Scherzer

Rahul Kopikare

Piu Bill Wong

Sigurd Schelstraete

Farrokh Farrokhi

Donald C Cox

Ali Rouhi

Vahbod Pourahmad

Jiangfeng Wu

Rajkumar Samuel

Kapil Gulati

Amir Hadi Djahanshahi

Jim Wood

Jihoon Yoon

Hsiao-Cheng Tsang

A transmitter including a transmit section and a frame formatter. The transmit section is to generate a stream of data to be transmitted using a plurality of antennas and separate the stream of data into a plurality of substreams corresponding to respective ones of the plurality of antennas. The frame formatter is to form respective frames of data from the plurality of substreams. Each of the frames of data includes a short preamble including short training symbols, a long preamble including long training symbols, and a signal field indicating a quantity of the plurality of antennas. The transmit section is further to transmit the frames of data using respective ones of the plurality of antennas.

Systems and methods for transmitting data frames using multiple antennas

Method, apparatus, and data packet format to implement transmit diversity in a multicarrier environment is disclosed. For diversity transmission operations, space frequency encoding techniques are employed creating distinguishable first and second time domain signals from a multicarrier frequency domain symbol bearing data of interest, which are then broadcast in parallel over first and second transmission units respectively. For diversity reception operations, complementary space frequency decoding is used to recover a corrected multicarrier frequency domain symbol from a time domain signal containing either this symbol, a space frequency modified symbol based on the multicarrier symbol, or a possible partial/complete combination of both. The data packet format includes portions defining a transmission diversity semaphore, a preamble enabling training of a receiver receiving the data packet, and a payload.

Multicarrier transmit diversity

A system including a circuit to compensate for sampling phase jitter. The system includes a channel estimator to determine, based on training symbols in a preamble of a data packet received via a communication channel, an estimate of the communication channel and a carrier frequency associated with the communication channel. The circuit compensates, based on the determined carrier frequency, a phase of the estimate of the communication channel to adjust for a carrier frequency offset associated with the communication channel, and, based on a data rate at which the data packet was received via the communication channel, selectively compensates the estimate of the communication channel for sampling phase jitter.

Systems and methods for compensating a channel estimate for phase and sampling phase jitter

Systems and techniques relating to wireless signal processing. A described technique includes receiving a signal, having subcarriers, over a wireless channel formed by a number-of-receive-antennas and a number-of-transmit-antennas; determining a signal quality measure of a received signal having subcarriers, the signal quality measure being based on channel gain matrices corresponding respectively to the subcarriers of the received signal, the channel gain matrices having dimensions of the number-of-receive-antennas by the number-of-transmit-antennas; determining a channel quality measure of the received signal that measures a frequency selectivity of the wireless channel; determining a data rate of information transmission over the wireless channel based on the signal quality measure and the channel quality measure, the signal quality measure serving as a primary determinant of the data rate and the channel quality measure serves as a secondary determinant of the data rate; and transmitting information over the wireless channel in accordance with the data rate.

Adaptively determining a data rate of packetized information transmission over a wireless channel

Techniques and systems for rate adaption in wireless systems are disclosed. A disclosed technique includes generating confidence measures for a plurality of data rates based at least on a first indicator and a second indicator, the first indicator corresponding to packet loss associated with packets transmitted by a device at a first data rate that is selected from the plurality of data rates, and the second indicator corresponding to one or more signal quality values associated with one or more packets received by the device; selecting, from the plurality of data rates, a second data rate based at least on the confidence measures; and transmitting one or more additional packets at the second data rate.

Rate adaptation in wireless systems

A transceiver comprising a transmit section and a frame formatter. The transmit section is configured to operate in a first mode and a second mode and transmit frames of data in the first mode and the second mode. The frame formatter is configured to operate in the first mode and the second mode. While operating in the first mode, the frame formatter is configured to generate a first frame of data in a first format, and the transmit section is configured to transmit a single set of long training symbols prior to transmitting the first frame of data. While operating in the second mode, the frame formatter is configured to generate a second frame of data in a second format, and the transmit section is configured to transmit a plurality of sets of long training symbols prior to transmitting the second frame of data.

Scalable MIMO-OFDM PHY for high throughput WLANS

A system including a channel estimator configured to generate an estimate of a communication channel based on a data packet received via the communication channel. A circuit is configured to determine a data rate at which the data packet was received via the communication channel, determine whether the data rate at which the data packet was received via the communication channel is greater than a threshold, and selectively compensate the channel estimate generated by the channel estimator for sampling phase jitter based on the determination of whether the data rate at which the data packet was received via the communication channel is greater than the threshold.

Systems and methods for compensating a channel estimate for sampling phase jitter

A device includes circuitry configured to receive orthogonal frequency-division multiplexing (OFDM) symbols of a training sequence via two or more receive antennas, and circuitry configured to correlate training samples of the OFDM symbols received via the two or more receive antennas to generate a correlation result, estimate a frequency offset using an angle of the correlation result, and correct samples of training symbols in at least one multiple-in-multiple-out (MIMO)-OFDM frame using the frequency offset.

MIMO-OFDM receiver processing

Interference cognitive devices are described. An interference cognitive device can be collocated with a transmitter of an interference cognitive transmitter (ICT), as receive chains or portions thereof at the ICT. An interference cognitive device can also be remote with respect to the transmitter, which operates in an interference cognitive network and receives data directly or indirectly from the interference cognitive device. The ICT uses the data to mitigate interference while continuing to operate in accordance with a performance metric.

Interference-cognitive transmission

A channel estimator for a wireless network receiver. The channel estimator includes a plurality of first circuits, each of the plurality of first circuits configured to multiply a respective channel estimate by a corresponding frequency domain signal, wherein the channel estimates correspond to an orthogonal frequency division multiplexing signal received by the wireless network receiver. A second circuit is configured to output a sum of results of multiplying the respective channel estimates by the corresponding frequency domain signals. A third circuit is configured to calculate, based on the sum, a correction factor, wherein the correction factor corresponds to a complex number representation of the respective channel estimates. A fourth circuit is configured to output, based on the correction factor and a previously calculated channel estimate, an updated channel estimate corresponding to the orthogonal frequency division multiplexing signal received by the wireless network receiver.

Channel estimator for updating channel estimates and carrier frequency offsets

A method is provided for Single Carrier-Frequency-Division Multiple Access (SC-FDMA) Physical Uplink Control Channel (PUCCH) format 1/1a/1b detection in a wireless communications receiver. The receiver accepts a plurality of multicarrier signals transmitted simultaneously from a plurality of transmitters, with overlapping carrier frequencies. For each multicarrier signal, a single tap measurement of time delay is performed using a Direction of Arrival (DoA) technique. In response to the single tap measurements, PUCCH 1/1/1format signals are detected. Prior to performing the single tap measurements, the multicarrier signals are decorrelated in the time domain, using corresponding orthogonal code covers. Subsequent to the single tap measurements, each multicarrier signal is decorrelated in the frequency domain, using a corresponding cyclic shift. Subsequent to decorrelating the multicarrier signals in the frequency domain, a Generalized Likelihood Ratio Test (GLRT) is performed for each decorrelated multicarrier signal.

Single carrier-frequency-division multiple access (SC-FDMA) physical uplink control channel (PUCCH) 1/1a/1b detection

Systems and techniques relating to wireless communication are described. A described technique includes transmitting a first signal wirelessly to a wireless communication device in accordance with a first transmit mode that is selected from a plurality of transmit modes; receiving a shortlist from the wireless communication device, the shortlist identifying a subset of the transmit modes, the subset of the transmit modes including two or more modes that are different from the first transmit mode; selecting a second transmit mode from the shortlist; transmitting a second signal wirelessly to the wireless communication device in accordance with the second transmit mode; and selectively cycling through any remaining modes of the shortlist based on a lack of reception of an acknowledgement to the second signal. The wireless communication device can be configured to generate the shortlist based on a channel quality analysis of a received version of the first signal.

Data rate adaptation in multiple-in-multiple-out systems

A system and method are provided for Single Carrier-Frequency-Division Multiple Access (SC-FDMA) Physical Uplink Control Channel (PUCCH) format 2/2a/2b detection. A receiver accepts a plurality of multicarrier signals transmitted simultaneously from a plurality of transmitters, with overlapping carrier frequencies. For each multicarrier signal, a single tap measurement of time delay is performed using a Direction of Arrival (DoA) technique. After performing a back-end processing operation, PUCCH 2/2a/2b format signals are detected. The back-end processing operation is selected from one of the following options: (1) decorrelation, channel estimation, equalization per user, and decoding per user; (2) channel estimation, equalization, and decoding per user; (3) decorrelation plus maximum likelihood detection (ML) per user; and, (4) ML detection over all users. Selection criteria is also provided.

Single carrier-frequency-division multiple access (SC-FDMA) physical uplink control channel (PUCCH) 2/2a/2b detection

Systems, devices, and techniques for MIMO (Multiple-In-Multiple-Out) based space-frequency coding can include, in at least some implementations, techniques that include selecting a spatial multiplexing rate M for a transmission of data via two or more antennas, the data comprising N data streams, applying a first mapping to map the N data streams to a first portion of the antennas for a first data tone; and applying a different second mapping to map the N data streams to a different second portion of the antennas for a second data tone.

Scalable space-frequency coding for MIMO systems

A system includes a mapping device. The mapping device groups encoded bits of OFDM symbols into first groups. For each of the first groups, the mapping device maps adjacent bits onto non-adjacent subcarriers of multiple subcarriers and in an alternating manner onto bits of a signal constellation such that: every other one of the adjacent bits are mapped to first bits on the signal constellation; and bits other than the every other one of the adjacent bits are mapped to second bits on the signal constellation. Each of the first groups has a corresponding complex number. The mapping device: groups predetermined numbers of the first groups into second groups, where each of the second groups corresponds to one of the OFDM symbols; and maps each of the second groups to one of the multiple subcarriers such that the multiple subcarriers are modulated based on the complex numbers.

Apparatuses and method for mapping bits of orthogonal frequency division multiplexing symbols to subcarriers and compensating for an imbalance between in-phase and quadrature-phase signals

Growing community of inventors

Los Altos, CA, United States of America

Ravi Narasimhan