Broadcom Corporation

Beceem Communications Inc.

Sam P Alex

Louay A Jalloul

Sriram Mudulodu

Rajesh Raja Manakkal

Djordje Tujkovic

Robert G Lorenz

Soumen Chakraborty

Manish Airy

Anuj Puri

Anupama Lakshmanan

Leena Zacharias

Bertrand Martyn Hochwald

Sindhu Verma

Javvadi Varaprasad

Sindhu Verman

A method and apparatus of selecting which of a plurality of receiver chains of a mobile unit to receive wireless signals, is disclosed. One method includes measuring a first receive signal quality while all of the plurality of receiver chains are receiving wireless signals, and measuring a second receive signal quality while a subset of the plurality of receiver chains are receiving wireless signals. The subset of the plurality of receiver chains are selected to receive wireless signal unless the first receive signal quality is a threshold better than the second receive signal quality. If the first receive signal quality is a threshold better than the second receive signal quality then all the plurality of receiver chains are selected to receive wireless signals.

Selecting receiver chains of a mobile unit for receiving wireless signals

A method for managing uplink communication in wireless communication network is provided. The method includes selecting one or more Mobile Stations (MSs) from a plurality of MSs based on a first signal parameter corresponding to each MS of the one or more MSs, one or more second signal parameters corresponding to each MS of the one or more MSs, and one or more threshold parameters. The first signal parameter is associated with a Base Station (BS) serving a MS. Further, the one or more second signal parameters are associated with one or more BSs neighboring to the MS. The one or more threshold parameters are associated with a communication parameter. Thereafter, the method includes modifying uplink Modulation and Coding Scheme (MCS) level of the one or more MSs.

Method and apparatus for managing uplink communication in wireless communication network

A method and apparatus of transmitting pilot tones and data in multi-carrier spatial multiplexing transmission is disclosed. The method includes a plurality of subscribers transmitting data to a base station through common frequency sub-carrier and symbol time tiles. Each of the multiple subscribers rotating frequency sub-carrier and symbol time locations of pilot tones within the frequency sub-carrier and symbol time tiles.

Methods of transmitting pilot tones and data in spatial multiplexing transmission

Embodiments for at least one method and apparatus of a subscriber station transceiver allocating and transmitting groups of subcarriers between a plurality of transceiver antennas are disclosed. One method includes the subscriber station transceiver receiving at least one downlink signal through each of the plurality of subscriber station antennas. The subscriber station transceiver characterizes a received signal of the at least one downlink signal over multiple subcarriers. The subscriber station transceiver allocates groups of subcarriers for uplink transmission through each of the plurality of subscriber antennas, wherein the allocation is based on the characterized received signal of the at least one downlink signal over multiple subcarriers.

Subscriber station transceiver allocation of groups of subcarriers between a plurality of transceiver antennas

A method and apparatus for estimating frequency offset and timing offset of a first Mobile Station (MS) in a communication system is provided. The method includes receiving a composite signal at a plurality of receiver antennas of a Base Transceiver Station (BTS). The composite signal includes a first signal transmitted from a first MS and a second signal transmitted from a second MS. The composite signal includes one or more tiles. Each tile includes a plurality of data sub-carriers, a plurality of first pilot sub-carriers, and a plurality of second pilot sub-carriers. A total phase offset of the first MS is estimated based on a complex conjugate product of pilot symbols of the plurality of first pilot sub-carriers. Thereafter, a first phase offset corresponding to the timing offset of the first MS is estimated based on a Power Delay Profile (PDP) of one or more first pilot sub-carriers. Finally, a second phase offset corresponding to the frequency offset of the first MS is determined based on the total phase offset and the first phase offset.

Method and apparatus for estimating frequency offset and timing offset of one or more mobile stations

A method of estimating a channel between a desired Mobile Station (MS) and a Base Transceiver Station (BTS) antenna of a one of a plurality of sectors of a BTS. The method includes receiving a composite signal at the BTS antenna. The composite signal comprises a desired MS signal and an interfering MS signal. Thereafter, a known desired random sequence and a known interfering random sequence is applied to pilot symbols of the composite signal, resulting in a first de-randomized signal and a second de-randomized signal. Finally, the channel estimate is obtained by weighting and summing the first de-randomized signal and second de-randomized signal.

Method and system for estimating channel of a mobile station in a communication system

The invention provides methods and systems for channel estimation. A method comprises receiving a plurality of signal frames, comprising at least a first zone and a second zone, from a plurality of base stations in the wireless communication system. Two or more first delay profiles corresponding to two or more base stations are determined using the first zone. The method further comprising detecting at least one aliased tap in a time domain channel response of the second zone using the two or more first delay profiles. Another method comprises receiving a signal frame, comprising at least a preamble symbol and a data part, from a base station. A first delay profile corresponding to the preamble symbol is determined and a second delay profile corresponding to the data part is obtained. The first delay profile is analyzed in conjunction with the second delay profile to detect one or more aliased taps in a time domain channel response of the data part. The detected one or more aliased taps are nulled/rectified.

Methods and systems for performing channels estimation in a wireless communication system

Method and apparatus for estimating frequency offset and timing offset of one or more mobile stations (MSs)

A method and system of training a communication system is disclosed. The method includes a first transceiver transmitting signals through one or more antennas of the first transceiver. A second transceiver selects a subset of a plurality of antennas of the second transceiver, wherein the selected subset provides a largest aggregate received signal power. The second transceiver transmits pilots on a subset of sub-carriers of multi-carrier signals through the selected subset of the plurality of antennas of the second transceiver. The first transceiver receives the pilots, and extracts channel knowledge from the received pilots.

Method of training a communication system

Methods and systems for estimating channel of one or more MSs in a collaborative MIMO communication system are provided. The method includes receiving a signal transmitted from a transmit antenna of a first MS and a transmit antenna of a second MS at a BTS using one or more receiver antennas. The method further includes computing one or more conjugate products for each of the first MS and the second MS using the signal. Thereafter, an average is determined over the plurality of receiver antennas and the plurality of tiles of the plurality of conjugate products for each of the first MS and the second MS. A phase determined based on the average of the plurality of conjugate products for the first MS and the second MS is divided into a first phase and a second phase for each of the first MS and the second MS. Additionally, the method includes determining a channel estimate for each tile of the first MS and the second MS at each receiver antennas. The method further includes performing predefined computations on the channel estimate of each tile of the first MS and the second MS at each receiver antenna of the BTS using the corresponding first phase and the corresponding second phase.

Growing community of inventors

Santa Clara, CA, United States of America

Sam P Alex