Ikanos Communications, Inc.

Quantenna Communications, Inc.

Qasem Aldrubi

Sam Heidari

Hossein Dehghan-Fard

Hossein Dehghan

Bahador Amiri

Sigurd Schelstraete

Behrooz Rezvani

Yuwen Su

Hojat Khelghati

Robert Ayrapetian

Julien D Pons

Echere Iroaga

Jason C Hu

Siva Simanapalli

Pengcheng Zhan

Sylvain Flamant

Karl Yick

Christopher Chow

Felipe Fuks

Arnaud Charton

Neville Young

A wireless access point (WAP) including: antennas, shared and discrete components forming transmit and receive chains coupled to the antenna for orthogonal frequency division multiplexed (OFDM) multiple-input multiple-output (MIMO) WLAN communications with wireless stations. The station set identifier identifies any legacy stations that do not support multi-user (MU) MIMO concurrent downlinks from the WAP, and a number of WLAN subnets for concurrent downlinks communications thereto. The subnet controller generates the WLAN subnets each having a discrete beacon channel together with a discrete medium access control (MAC) for collision sense multiple access (CSMA) uplinks from associated stations to the WAP, and concurrent downlinks from the WAP including concurrent downlinks to legacy stations associated with different subnets; and the subnet controller configured to inject virtual access control indicia into each of the subnets to control uplinks from legacy stations on each of the subnets to the WAP.

WAP supporting complementary subnets in a WLAN

A wireless access point (WAP) including: antennas, shared and discrete components forming transmit and receive chains coupled to the antenna for orthogonal frequency division multiplexed (OFDM) multiple-input multiple-output (MIMO) WLAN communications with wireless stations. The station set identifier identifies any legacy stations that do not support multi-user (MU) MIMO concurrent downlinks from the WAP, and a number of WLAN subnets for concurrent downlinks communications thereto. The subnet controller generates the WLAN subnets each having a discrete beacon channel together with a discrete medium access control (MAC) for collision sense multiple access (CSMA) uplinks from associated stations to the WAP, and concurrent downlinks from the WAP including concurrent downlinks to legacy stations associated with different subnets; thereby enabling concurrent downlink communications with said legacy stations despite their lack of support for MU-MIMO.

A link optimizer for optimizing a link on a wireless local area network (WLAN). The link optimizer including: a beamform matrix generator configured to generate discrete candidate beamforming matrices for spatially modulating successive communication packets from a multiple-input multiple-output (MIMO) capable transmitter one of the WLAN nodes that supports beamforming to a recipient one of the nodes that does not support beamforming; and a beamform evaluator configured to evaluate discrete ones among the set of candidate beam forming matrices generated by the beamform matrix generator based on receipt acknowledgements from the recipient one of the nodes for each successive communication packet transmitted from the MIMO capable transmitter one of the nodes; and to utilize a successfully evaluated one of the candidate beam forming matrices for transmission of subsequent communication packets from the MIMO transmitter one of the nodes to the recipient one of the nodes.

Method and apparatus for link optimization in a Wi-Fi home network

A wireless access point (WAP) including: a station set identifier and a subnet controller. The station set identifier is configured to identify at least one set of at least two station nodes among the plurality of station nodes and complementary communication options for each station in the at least one set which facilitate concurrent communications between the WAP and the stations in the set. The subnet controller is configured both to generate subnets equal in number to a number of stations in at least one set, and for each subnet an associated beacon channel discrete from the beacon channels of other subnets, together with any required aggregate channels matching each station's identified communication option and an associated medium access control, and further to control transmission of data from the WAP to the at least two station nodes concurrently on the associated subnets.

Peak-to-average ratio reduction is achieved by detecting peaks in an original analog signal that exceed a given threshold. Segments of the original analog signal containing such peaks are treated (e.g., by attenuation) and a composite analog signal is assembled that includes treated and untreated segments of the original analog signal. The composite analog signal is processed to perform analog-to-digital conversion to generate a composite digital signal. Segments of the composite digital signal corresponding to the treated segments of the original analog signal are reverse-treated or otherwise treated again to undo treatment of the segments of the original analog signal. A final output digital signal is generated that corresponds to the original analog signal in digital form.

Method and apparatus for peak-to-average ratio reduction

A multi-tone transceiver including: a transform component, a tone selector, an error detector, an aggregator and an oscillator. The transform component transforms received communications from the time domain to the frequency domain. The tone selector selects a sub-set of the received tones which exhibit an elevated signal-to-noise ratio (SNR) as a clock recovery tone set (CRTS) and drops and add tones to the CRTS as required by changes in the SNR of the individual tones. The error detector detects phase errors in each received tone of the CRTS. The aggregator calculates an average aggregate phase error from all tones in the CRTS. The oscillator controls clocking of the transceiver. The oscillator is responsive to the average aggregate phase error to adjust a clock phase in a direction which reduces a phase error with a clock on the opposing transceiver.

Method and apparatus for clock recovery in XDSL transceivers

A digital subscriber line XDSL communication system for optimizing dynamic range in digital multi-tone modulated (DMT) modems. The system comprises a digital subscriber line access multiplexer (DSLAM) and at least one modem. The DSLAM distributes a near end crosstalk (NEXT) model of anticipated disturbance from neighboring disturber subscriber lines. The at least one modem has a transmit path and a receive path. The at least one modem couples to the DSLAM and is responsive to the distributed NEXT model to adjust a dynamic range of an analog portion of the receive path to accommodate the anticipated disturbance modeled in the distributed NEXT model.

Method and apparatus for optimizing dynamic range in DMT modems

A digital subscriber line 'XDSL' communication system for provisioning multi-tone modulated communications over two subscriber lines with two modems. The first modem has shared and discrete components forming a transmit path coupled exclusively to an end of a first of the two subscriber lines and a receive path coupled exclusively to an end of a second of the two subscriber lines. The second modem also has shared and discrete components forming a transmit path and a receive path having couplings of transmit and receive path components to corresponding opposing ends of the two subscriber lines diametrically opposite to those of the first modem, whereby the modems provision the first subscriber line exclusively for unidirectional communication from the first to the second modem, and provision the second subscriber line for unidirectional communication in the opposite direction, specifically from the second modem to the first modem. A related method and modem are disclosed.

Method and apparatus for DSL communication over a 4 wire system

A multi-tone transceiver with a components forming a transmit path and a receive path configured to couple via a subscriber line to an opposing multi-tone transceiver for frequency division multiplexed multi-tone modulated communications therewith is disclosed. A noise margin channel identifier is configured to identify within a received tone set, discrete tones each associated with a corresponding one of at least two channels differing from one another in a relative noise margin of associated tones. A Viterbi decoder is responsive to the channel identification provided by the noise margin channel identifier to discretely decode each of the at least two channels; thereby improving the fidelity of the error correction provided by the Viterbi decoder by discretely processing the identified channels within the received set of tones.

Method and apparatus for forward error correction

A digital subscriber line 'XDSL' communication system for optimizing dynamic range in digital multi-tone modulated (DMT) modems. The system comprises a digital subscriber line access multiplexer (DSLAM) and at least one modem. The DSLAM distributes a near end crosstalk (NEXT) model of anticipated disturbance from neighboring disturber subscriber lines. The at least one modem has shared and discrete components forming a transmit path and a receive path. The at least one modem couples to the DSLAM and is responsive to the distributed NEXT model there from to adjust a dynamic range of an analog portion of the receive path to accommodate the anticipated disturbance modeled in the distributed NEXT model.

The current invention provides a method and apparatus for wireline characterization is disclosed. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The apparatus may be incorporated into physical or logical modems. In an embodiment of the invention an apparatus for wireline characterization in a modem with a transmit path and a receive path each configured to couple with a remote modem via a wireline in which available communication bandwidth is split into a number of independent sub-channels is disclosed. The apparatus comprises: a tone selector, a cumulative loss estimator and a shift register. The tone selector selects a subset of the number of sub-channels within the bandwidth of a received wireline communication for which subset the sum of the square roots of the corresponding sub-channel indices may be expressed as an integer power &ldquo;n&rdquo; of 2. The cumulative loss estimator cumulates the insertion losses across the selected subset of the sub-channels and outputs a binary value corresponding thereto. The shift register couples to the cumulative loss estimator to scale a magnitude of the binary value received from the cumulative loss estimator by an amount proportionate to &ldquo;n&rdquo; to obtain a scaled electrical distance estimate for the wireline. Corresponding method and means are disclosed.

Method and apparatus for wireline characterization

The current invention provides a method and apparatus for determining insertion loss in wireline communication systems. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The method for calculation of the insertion loss uses a received signal and a discrete subset of frequency ranges, e.g. DMT tones, within that signal. For each of the subset of frequency ranges the average received power on each of the selected set of tones is determined. Next the average power on each received subset of tones is converted to log using a simple log estimation circuit that avoids the complexity associated with log tables and other prior art methods of computing logarithms. Then the sum of the log of the average power received in each of the selected subset of tone bins is determined. Next, the known transmitted power for the selected subset of tones is expressed as log , is summed and is then subtracted from the sum of the log of the average power received. Then using a simple electrical length estimation circuit the insertion loss is calculated. A corresponding apparatus is disclosed.

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Fremont, CA, United States of America

Qasem Aldrubi