Abstract: 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.

Abstract: A GPS enabled timepiece. A Global Positioning System (GPS) enabled timepiece in accordance with the present invention comprises a timepiece, the timepiece comprising a local oscillator, and a GPS receiver, coupled to the timepiece, the GPS receiver using the local oscillator to predict a time arrival of a GPS message from a GPS satellite, wherein the GPS receiver is powered on based on the predicted time.

Abstract: An access contention scheme is described for use by a station in a network of stations. Access contention by a station having a frame to be transmitted includes detecting contention control information for a contention period and determining from the contention control information if the station is permitted to contend for access to a transmission medium to which the stations are connected during the contention period. When a contention control indicator is detected for a contention period, a station having a frame to transmit determines from the contention control indicator if it is permitted to contend for access to the transmission medium during the contention period.

Abstract: A data packet, comprising a preamble and the preamble comprising a plurality of synchronization bits, is received where the preamble may be of either a first preamble type or a second preamble type. Channel estimation is performed using at least a first portion of the plurality of synchronization bits. It is determined whether the preamble is of the first preamble type or of the second preamble type, where the determination overlaps in least in part with the channel estimation.

Abstract: A method and apparatus for detecting radar signals in single and multiple (extension) channel wireless network frequencies uses spectral and DC analysis. Spectral images produced through a Fast Fourier transform may be captured and analyzed to determine if any radar signals may be present within the selected wireless network frequencies. A plurality of spectral images may also be analyzed to determine if frequency shifting radar signals are present as well. DC analysis of the power contained at the wireless carrier frequencies may detect radar signals that may be centered near those frequencies.

Abstract: A dual-band GPS receiver and method and apparatus for downconversion of dual-band GPS signals. A dual-band GPS receiver in accordance with the present invention comprises an antenna, a Radio Frequency (RF) section, coupled to the antenna, and a baseband section, coupled to the RF section, wherein the RF section comprises a receiver, the receiver receiving signals from a first GPS frequency band and a second GPS frequency band, a local oscillator having a local oscillator frequency, and a mixer, coupled to the receiver and the local oscillator, for selectively mixing the local oscillator frequency with the first GPS frequency band and a second GPS frequency band, wherein the local oscillator frequency downconverts the first GPS frequency band and the second GPS frequency band into a common downconversion frequency band.

Abstract: Communicating over a network of communication stations includes monitoring for reception of an electromagnetic wave that has a power above a threshold and a frequency in a predetermined frequency interval, and selecting carrier frequencies for modulating information onto signals transmitted over the network. The carrier frequencies are selected based at least in part on whether an electromagnetic wave having a power above the threshold and a frequency in the frequency interval has been received in a predetermined time interval, and based at least in part on a demand by one or more stations in the network for capacity for communicating over the network.

Abstract: Providing duty cycle correction can include determining whether a clock signal has a duty cycle greater than 50% based on averaging the clock signal and comparing that averaged clock signal to ½ VDD. When the duty cycle is greater than 50%, the clock signal can be selected. When the duty cycle is less than 50%, the inverted clock signal can be selected. Thus, a duty cycle corrected clock signal can be generated based on the clock signal or the inverted clock signal. Notably, a duty cycle control signal can be adjusted based on comparisons of an averaged, duty cycle corrected clock signal and predetermined low/high voltage ranges. Components performing comparing functions can be strobed based on a count performed on the clock signal.

Abstract: Accurate position capability can be quickly provided using a Wireless Local Area Network (WLAN). When associated with a WLAN, a wireless device can quickly determine its relative and/or coordinate position based on information provided by an access point in the WLAN. Before a wireless device disassociates with the access point, the WLAN can periodically provide time, location, and decoded GPS data to the wireless device. In this manner, the wireless device can significantly reduce the time to acquire the necessary GPS satellite data (i.e. on the order of seconds instead of minutes) to determine its coordinate position.

Abstract: A method and corresponding system for communicating between stations in a network is presented. The method includes providing repeated beacon transmissions from a coordinator station for coordinating transmissions among the stations; transmitting a signal from a first station and receiving the signal at a second station; and performing one or both of: generating the signal based on a local clock at the first station and time adjustment information in a beacon transmission received by the first station, and sampling the signal at sample times based on a local clock at the second station and time adjustment information in a beacon transmission received by the second station.

Abstract: 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.

Abstract: A method and system of optimizing transmit beam forming in a multiple radio wireless system is provided. A stimulus signal can be provided to an analog receive input of a device under test (DUT), wherein the DUT includes multiple radios. A receive phase and amplitude can be measured at baseband using the stimulus signal for each radio. At this point, a receive weight and its conjugate can be determined using the receive phases and amplitudes. A calibration vector and its conjugate can also be determined, wherein a product of the receive weight conjugate and the calibration vector conjugate generate a transmit weight. This transmit weight can be applied to transmit signals during the transmit beam forming using the multiple radios.

Abstract: A variable transconductance device for a mixer apparatus is provided. The apparatus includes at least one variable current source circuit having a plurality of selectively enabled current source stages. Each of the current source stages, when enabled, is actuable to establish a conductive path between a first supply level and an output terminal. The device further includes at least one variable transconductance circuit having a plurality of selectively enabled transconductance stages. Each transconductance stage, when enabled, is actuable to establish a conductive path between a second supply level and the output terminal. An output current signal is generated at the output terminal responsive to actuation of the variable transconductance circuit by an input voltage signal, whereby the output current signal exhibits a power gain adjustably determined responsive to the numbers of current source and transconductance stages selectively enabled.

Abstract: A method and apparatus for detecting radar signals in single and multiple (extension) channel wireless network frequencies uses spectral and DC analysis. Spectral images produced through a Fast Fourier transform may be captured and analyzed to determine if any radar signals may be present within the selected wireless network frequencies. A plurality of spectral images may also be analyzed to determine if frequency shifting radar signals are present as well. DC analysis of the power contained at the wireless carrier frequencies may detect radar signals that may be centered near those frequencies.

Abstract: Method and apparatus to dynamically configure the signal reception selectivity of a plurality of transceivers is described. In one embodiment, a transceiver includes a receiver circuit having two or more filter circuits. Each of the filter circuits is configured to pass RF signals from a different portion of an overall receiver bandwidth. When two or more receivers in proximity to one another are simultaneously operating, the filter circuits of the respective receiver are dynamically configured to different RF frequency passbands to minimize interference and cross talk between receivers and transmitters.

Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.

Abstract: A communication device includes a communication port that includes a digital to analog converter (DAC) that may be configured to output for transmission an analog signal that corresponds to a digital input such as link data that is to be transmitted on a physical link. The communication port further includes a control unit coupled to the DAC and may be configured to provide a bias current to the DAC during operation. In addition, the control unit may further be configured to reduce the bias current to the DAC dependent upon a mode of operation of the communication port and whether there is data to transmit.

Abstract: Mobile access points typically run on batteries, and therefore, can operate for a limited amount of time without an external power source. However, because the access point service model requiring the access point to always be available and the access point's limited battery capacity reduces the time that the mobile access point can be used. Functionality can be incorporated in mobile access points to implement power saving mechanisms by altering the service model that requires the access point to always be available. Configuring the access point to enter into a low powered state for a predefined period of time can conserve mobile access point power and prolong battery life. Functionality for implementing power saving mechanisms can also be incorporated on fixed access points for efficient utilization of computing resources.

Abstract: Media Access Control (MAC) layer transmit and receive buffering with multi-level prioritization. The receive buffering allocates receive buffers for receiving frame data from a PHY interface in priority order using both a static and dynamic buffer allocation, and delivers completed buffers queued in a multi-level priority queue to a host interface highest priority first. The transmit buffering delivers completed buffers queued in a multi-level priority queue to the PHY interface in priority order. When the multi-level priority queue contains a buffer that is higher priority than one being prepared for transmit, a priority-based interruption causes the transmit processing of the buffer to be suspended at its current state with the higher priority buffer taking its place. Upon completion of the higher priority buffer, the suspended buffer is resumed at its current state.

Abstract: This discloses an integrated circuit and at least one CMOS analog circuit including a first circuit component generating an output signal received by a second circuit component to generate a feedback signal received by the first component to regulate the output signal, where the transistors of the first circuit component consist of first MOS transistor instances compliant with a first core voltage and the feedback signal requires the transistors of the second circuit component to consist of at least one second MOS transistor instance compliant with a second core voltage above the first core voltage. The CMOS analog circuit may implement an amplifier, a transconductance amplifier and/or a telescopic amplifier. The first core voltage may at most 1.2 volts and the second core voltage may be at least three volts. The first MOS transistors may be thin oxide transistors and the second MOS transistors may be thicker oxide transistors.