Atheros Communications, Inc.

Ati International Srl

Chromatic Research, Inc.

Other

Qualcomm Incorporated

John S Thomson

William John McFarland

Paul J Husted

Lars E Thon

Stephen C Purcell

James Simon Cho

Jeffrey M Gilbert

Ardavan Maleki Tehrani

David Kuochieh Su

Kai Shi

Yi-Hsiu Wang

Teresa H Meng

Manolis Terrovitis

Xiaoru Zhang

Arie Shor

Masoud Zaragari

James Battle

Keith K Onodera

Paul E Onnen

William N Ng

Yi-Hsu Wang

James C Hillegass

Yaobing Deng

Mark Eastom

Richard R Fritz

John C Gateley

James A Grinsfelder

Stephen A Grove

James A Nordgaard

Eric Steven Hockett

Nikolay G Sokratov

James G Swanson

Boris Mamedov

Ahmed H Hassan

Keith Onedera

Sankara S Venkateswaran

Paul J Hustad

William J Mcfarland

Tao-Fei S Ng

In some wireless local area networks (WLANs), signals of different modulation types and rates can be received. To operate optimally, the gain of an amplifier in a receiver can be set based on a specific modulation type and rate. For example, the gain of a receive path amplifier can be changed based on one or more unique identifying characteristics in a received data packet. Once the unique identifying characteristics are located, they can be analyzed to determine which modulation type and rate are represented. The appropriate gain of the amplifier can be set based on the modulation type and rate. Advantageously, subsequent data symbols can be amplified with the set gain, thereby ensuring that the receiver optimally receives those data symbols.

Method and system for optimizing gain changes by identifying modulation type and rate

A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between good and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.

Decoding system and method for digital communications

A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.

Dual frequency band wireless LAN

A radio communication device is tested by forwarding relevant signal characteristic data derived at the physical (PHY) layer to the media access control (MAC) layer for processing, analysis and feedback to the radio circuit to improve performance. The relevant signal characteristics are forwarded to the MAC within (appended to) a data packet. Thus, the relevant signal characteristic is forwarded to the MAC along an existing data path (a path originally designed to transfer the receive frame only, but now transfers the combined receive frame with the attached radio characteristic). The radio characteristic may be used for testing and/or tuning the radio circuit. In one embodiment, the radio characteristic is a frequency domain representation of a received signal. The radio is tuned based on a channel estimate derived from comparison of frequency domain representations of transmitted and received signals.

Method and system for testing and optimizing the performance of a radio communication device

A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between god and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.

Specific bits of an incoming transmission are compared against a predetermined bit pattern. If the selected bits do not match the predetermined bit pattern, then the incoming transmission is rejected as a false packet. The predetermined bit pattern can include legal values for predetermined bits in a plurality of fields. Notably, these legal values are set by a networking standard. A parity check may check may be performed in addition to checking for predetermined bits in other fields. A user interface can be used to determine the predetermined bit pattern.

Method and system for detecting false packets in wireless communications systems

A method for maintaining an accurate channel estimate. The method includes providing a reference channel estimate based on at least one long training symbol, and generating a frequency domain representation of a first data symbol including a plurality of pilots. The method then includes tracking phase change in the plurality of pilots of the first data symbol relative to pilots of the at least one long training symbol to produce correction factors, and adjusting the reference channel estimate based upon the correction factors.

Efficient pilot tracking method for OFDM receivers

A system and method are disclosed for processing a signal that includes receiving encoded data including a plurality of input symbols; generating an input symbol set from the plurality of input symbols; looking up a plurality of output samples for the input symbol set; and outputting the plurality of output samples.

Look up table based upsampling and digital filtering

A method for correcting influence of frequency offset between a receiver and a transmitter by evaluating training symbols received during a preamble period. The method includes producing, based on at least one long training symbol, a first vector whose first vector angle is indicative of a fine offset between the receiver and the transmitter, producing a fine offset estimate based on the first vector angle, and multiplying, with a signal having a frequency based upon the fine offset estimate, data symbols that are received after the at least one long training symbol is received.

Fine frequency offset estimation and calculation and use to improve communication system performance

A method and system is presented for a digital licensing scheme that separates the license from the digital file containing the copyrightable material. According to the present invention, the files can be downloaded from any server, and transferred from user to user, even after the file has been licensed. The present invention utilizes producer software running on a vendor's computer, server software running on a computer provided by the license provider, and player software operating on the user's computer. Digitally encrypted communication streams keep communications between the producer software, the license provider, and the player software confidential. A software component running on the user's computer checks to make sure that the appropriate product license has been purchased. This is accomplished by comparing the product ID in the product license with the product ID contained in the product file. The software also checks that the person seeking to play the product file is the user that actually paid for the license. This is accomplished by comparing the user ID in the product license with a user ID in a user license. Finally, an operating system ID found in the user license is compared with the same information obtained from the currently running operating system, to ensure that the user license was created for the currently operating computer.

Method and system for licensing digital works

The present invention provides a method of and an apparatus for changing the gain of a receive path amplifier during the middle of a packet transmission, and particularly changing the gain during a guard interval between a symbol with encoding bits disposed therein and a subsequent data symbol encoded in a manner corresponding to the encoding bits.

Method and apparatus for maximizing receiver performance utilizing mid-packet gain changes

A circuit for texture tag checking includes a first comparison gate which compares a first dimension field of a tag with a first dimension element for a group of texels associated with a sample point. A second comparison gate compares a second dimension field of the tag with a second dimension element for the group of texels. A logic gate, coupled to each of the first and second comparison gates, is associated with one texel of the group of texels. The logic gate outputs a predetermined signal if the first and second dimension fields of the tag are the same as the first and second dimension elements, respectively.

Optimizing texture tag checking for three-dimensional computer graphics

Growing community of inventors

Santa Clara, CA, United States of America

John S Thomson