Qualcomm Incorporated

J Rodney Walton

Mark S Wallace

John Wendell Ketchum

Steven J Howard

Oliver Michaelis

Sanjiv Nanda

John Edward Smee

Subrahmanyam Dravida

Irina Medvedev

Ravi Kumar

Qiang Fu

Naga Bhushan

Fuyun Ling

Peter J Black

Mehmet Yavuz

Jack M Holtzman

Franklin Peter Antonio

Shravan K Surineni

Ivan Jesus Fernandez Corbaton

Peter Monsen

Ivan Fernandez

Xiandong Zhang

Pilots suitable for use in MIMO systems and capable of supporting various functions are described. The various types of pilot include&#x2014;a beacon pilot, a MIMO pilot, a steered reference or steered pilot, and a carrier pilot. The beacon pilot is transmitted from all transmit antennas and may be used for timing and frequency acquisition. The MIMO pilot is transmitted from all transmit antennas but is covered with different orthogonal codes assigned to the transmit antennas. The MIMO pilot may be used for channel estimation. The steered reference is transmitted on specific eigenmodes of a MIMO channel and is user terminal specific. The steered reference may be used for channel estimation. The carrier pilot may be transmitted on designated subbands/antennas and may be used for phase tracking of a carrier signal. Various pilot transmission schemes may be devised based on different combinations of these various types of pilot.

Pilots for MIMO communication systems

An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An 'effective' uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals.

Multi-antenna transmission for spatial division multiple access

Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of 'transmission channels' at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be 'pre-conditioned' and prior to transmission.

Coding scheme for a wireless communication system

According to one aspect of the invention, a method is provided in which a control channel used for transmitting control information is partitioned into a plurality of subchannels each of which is operated at a specific data rate. For each of one or more user terminals, one of the subchannels is selected based on one or more selection criteria for transmitting control information from an access point to the respective user terminal. Control information is transmitted from the access point to a user terminal on a particular subchannel selected for the respective user terminal. At the user terminal, one or more subchannels are decoded to obtain control information designated for the user terminal.

Method and apparatus for providing an efficient control channel structure in a wireless communication system

Certain embodiments of the present disclosure relate to a method and an apparatus for managing and optimizing service discovery in a peer-to-peer (P2P) wireless network. Nodes of the P2P network advertise their capabilities to their peers in the form of services. Efficient propagation and management of node's services to other nodes is proposed in the present disclosure.

Methods and systems for service discovery management in peer-to-peer networks

Techniques for detecting and demodulating a signal/transmission are described. Signal detection is performed in multiple stages using different types of signal processing, e.g., using time-domain correlation for a first stage, frequency-domain processing for a second stage, and time-domain processing for a third stage. For the first stage, products of symbols are generated for at least two different delays, correlation between the products for each delay and known values is performed, and correlation results for all delays are combined and used to declare the presence of a signal. For demodulation, the timing of input samples is adjusted to obtain timing-adjusted samples. A frequency offset is estimated and removed from the timing-adjusted samples to obtain frequency-corrected samples, which are processed with a channel estimate to obtain detected symbols. The phases of the detected symbols are corrected to obtain phase-corrected symbols, which are demodulated, deinterleaved, and decoded.

Receiver for wireless communication network with extended range

Certain embodiments of the present disclosure relate to methods for increasing a capacity in a peer-to-peer (P2P) wireless network. The methods include generating a connectivity metric (CM) value indicative of a number of other wireless nodes of the P2P wireless network to which the wireless node is connected, transmitting the CM value, and then transmitting full connectivity information maintained by the wireless node at a frequency determined based on the CM value. The disclosed methods therefore allow well-connected nodes of the P2P wireless network to be exploited in a manner that increases the overall connectivity of all the nodes in the network.

Methods and systems for exploitation of well-connected nodes in peer-to-peer wireless networks

Certain embodiments of the present disclosure relate to methods for increasing a capacity in a peer-to-peer (P2P) wireless network. The methods include generating a connectivity metric (CM) value indicative of a number of other wireless nodes of the P2P wireless network to which the wireless node is connected, receiving a query for services, and then responding to the query for services if the CM value is greater than a defined CM threshold value. The disclosed methods therefore allow well-connected nodes of the P2P wireless network to be exploited in a manner that increases the overall connectivity of all the nodes in the network.

Certain embodiments of the present disclosure relate to a method for improving the effective coverage of nodes within a peer-to-peer (P2P) wireless network. Collection of nodes of the P2P network can have a larger aggregate coverage footprint than any given single node. This inherent multi-site property of P2P wireless networks can be exploited to provide each node with benefits of multi-user diversity, thus improving discovery of devices in the P2P network.

Methods and systems for peer-to-peer network discovery using multi-user diversity

A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.

Growing community of inventors

Carlisle, MA, United States of America

J Rodney Walton