Abstract: A method of conserving power in a WLAN receiver is provided wherein processing tasks that need only to be operated for a brief period of time during the reception of a received packet are enabled only during the brief period of time. The enabling includes providing multiple power control signals that are controlled by a state machine for enabling and disabling the processing tasks.

Abstract: A system and method for using asymmetric companion codecs to establish and maintain a communication. A communication system endpoint replaces instances of a companion codec with the members of a group of all of the companion codecs for the endpoint and performs appropriate translations of compatible codecs to provide a communication between communication system endpoints.

Abstract: A channel norm-based ordering and whitened decoding technique (lower complexity iterative decoder) for MIMO communication systems performs approximately the same level of performance as an iterative minimum mean squared error decoder. Decoding a signal vector comprises receiving a signal vector yk, multiplying the received signal vector yk by a conjugate transpose of a channel matrix H*. A column vector zk is generated. The entries of the column vector zk are reordered and an estimated channel matrix {tilde over (H)} is generated. The estimated channel matrix {tilde over (H)} decomposed using a Cholesky decomposition and generating a triangular matrix L. Triangular matrix L is solved backwards and a signal vector {tilde over (s)}k estimated. An estimate of the transmitted symbol vector ?k is generated.

Abstract: A method provides frequency and phase offset estimation in a SCDMA burst receiver (such as a DOCSIS 2.0 SCDMA burst receiver) by application of the known Least Square (LS) parameter estimation algorithm to a pre-known transmitted sequence, called preamble, in order to optimally characterize the phase and frequency offsets affecting the transmitted data. The LS parameter estimation algorithm is adapted to SCDMA burst receiver specifications by changing index calculations to fit according to SCDMA preamble locations. Improved estimation accuracy can be achieved by using weighted least squares that disregard symbols affected by impulse and burst noise. Weighted least squares can further impart more weight to last symbols to more accurately estimate contemporary impairments. The method is particularly useful for communication systems having large frequency and phase offsets as in the DOCSIS 2.0 SCDMA burst receiver.

Abstract: The present invention jointly controls rate and power in a fashion that enables control of the two variables in one dimension. In some embodiments, this is done by ordering the possible transmit rate (320) and transmit power (340) combinations in a logical sequence that meets specific conditions. The present invention can first minimize the transmit time and then reduce the transmit power. The present invention can maintain the maximum rate possible that enables the receiving station to decode packets with an acceptable probability.

Abstract: A single sleep mode controller which ensures that there is at least a corresponding minimum voltage level across capacitors when the corresponding regulators are turned off. In an embodiment, the sleep mode controller uses a single comparator which compares the voltages across capacitors in a time division multiplexed (TDM) manner, and initiates the charging operation for the capacitor if the voltage level falls below a corresponding minimum voltage level. The sleep mode controller continues the charging operation until the voltage level exceeds a corresponding upper threshold value. Due to the use of the single controller, power and/or space savings may be attained.

Abstract: A reduced search space minimum distance decoding algorithm provides average probability of error performance close to that of optimal MAP decoding. The decoding algorithm provides dramatic complexity reductions compared with MAP decoding. A sub-optimal decoder receives signal vectors y1 . . . yk. Soft output bits are generated as is a reduced search space V via a reduced search space table creation unit in response to the soft output bits and an estimated channel H. A signal vector b is generated via a maximum likelihood decoding unit in response to the reduced search space V and the signal vectors y1 . . . yk.

Abstract: A prefilter is trained as follows. The frequency response B of a conditioned channel is determined without reference to the prefilter, and the frequency response W of the prefilter is computed from the frequency response B of the conditioned channel.

Abstract: A novel mechanism for performing high accuracy cable diagnostics. The mechanism utilizes time domain reflectometry (TDR) to detect and identify cable faults, perform estimations of cable length, identify cable topology, identify load and irregular impedance on metallic paired cable, such as twisted pair and coaxial cables. The TDR mechanism transmits pulses whose shapes are programmable and analyzes the signal reflections. The shapes of the pulses transmitted can be optimized in accordance with the channel characteristics. Further, the TDR mechanism is adapted to operative in the presence of high pass filters in the channel.

Abstract: A new system and method is described, utilizing a scheduler based on a transmission power consumption calculation and prioritizing algorithm. The system utilizes the (APSD) protocol specified in the 802.11e draft for saving power in wireless local area networks. The system comprises an access point having a priority queue, one or more stations, an APSD frame comprising an association ID for identifying one of the stations and a scheduled wake-up time for the identified station. An algorithm is employed for calculating the total transmission power consumption of downlink data for the stations. The AP originates and transmits to the one or more stations the APSD frame of the scheduled activation delay time. The current data to be transmitted to each station is accessed by the algorithm to determine the total transmission power consumption to each station.

Abstract: A method and system for conserving power in a WLAN receiver is provided by a channel estimator for detecting transmitted errors in a transmitted packet and providing equalization for the detected channel errors; a separate pilot processor for detecting off set errors from the channel estimation and providing off set correction to said equalization for the whole data portion of the packet after the preamble and a control response to the start of each packet for enabling said channel estimator during the preamble and thereafter disabling said channel estimator for the remainder of the packet and storing the estimated value.

Abstract: A method of power consumption reduction in integrated circuits comprising extensive use of differential signaling within said circuits. Differential signaling comprises a pair of coupled, symmetrically opposite and operatively dependent electronic signals each driven by voltages of the same magnitude, but of opposite polarity with respect to a common ground. The drive voltages of each signal are of relatively low potential as compared to the core operating voltage of present day devices. The low-voltage pair of signals tends to create offsetting fields of electromagnetic interference from the flow of current within their respective conductors which tends to minimize inductive effects (and therefore corruption of signals) in adjacent signal lines. Differential signaling replaces all or as many single-end signals as possible throughout the device resulting in relatively lower power usage as compared to present devices.

Abstract: A method selects the data rate for pulse code modulation upstream transmission by determining an approximate transmit power before the upstream transmission reaches a transmit equalizer based on a recorder power output and a distance halfway between an outermost constellation point and a point following the outermost point. The determined approximate transmit power is multiplied by the power of the transmit equalizer to determine a post-equalizer transmit value. A data rate is selected which is less than a predetermined regulatory limit.

Abstract: A wireless device (e.g. an access point) is adapted to communicate wirelessly with a class 1 device and a class 2 device, wherein the class 2 device is capable of communicating in a manner that is not compatible with the class 1 device. The wireless device may comprise host logic, an antenna, and a MAC coupled the host logic and the antenna. The MAC may cause the wireless device to emit a poll that is recognized differently by the class 1 device as compared to the class 2 device and that causes the wireless device to operate for a reserved period of time in which the class 2 device can communicate in a manner that is not compatible with the class 1 device.

Abstract: A method of communicating across a channel includes receiving information having a known bandwidth and a known spectrum. The information is preferably in the form of a multicarrier modulated signal, e.g., a DMT signal. In one aspect, this information is received at a receiver having a reduced channel bandwidth. An aliasing spectrum can be calculated based on the known spectrum and the frequency difference between the known bandwidth and the reduced-channel bandwidth. The received information can then be modified based upon the aliasing function to compensate for alias distortion. For example, the received information can be modified by modifying the noise component or signal-to-noise ratio of the received information.

Abstract: System and method for enabling the low power detection of a transmitted sequence. A preferred embodiment comprises the replacement of a portion of a preamble (after the application of any needed scrambling) with an expected sequence field (such as the expected sequence field 410). The expected sequence field may contain a sequence of values known at a receiver or a periodic sequence. The addition of the expected sequence field does not affect the length of the preamble and is compatible with existing receivers.

Abstract: The invention generally provides a method of intelligent frequency hopping such as in Bluetooth and Home RF networks. The method (100) includes the acts of sampling a plurality of channels in a frequency band and identifying each channel as a good channels or a bad channel (110), determining the size of a good window and the size of a bad window (120), and assigning a plurality of good channels to a good window (130) and a plurality of bad channels to a bad window (140). Accordingly, the method increases the reliability and throughput of wireless networks.

Abstract: A high speed parser containing a content addressable memory (CAM) providing select values to multiplexers. The CAM is programmed to implement search rules which examine input data for specific semantics according to a protocol, and outputs the specific bit positions at which the corresponding desired data units are present. The outputs are provided to multiplexers to cause the desired data units to be selected on the corresponding output paths of the multiplexors.

Abstract: A transmit channel (gt1, h, gr2) through which a first wireless communication transceiver is to transmit to a second wireless communication transceiver can be estimated using information indicative of a relationship between the transmit channel and a receive channel (gt2, h, gr1) through which the first wireless communication transceiver receives communications from the second wireless communication transceiver. The relationship information (35) is combined (37) with further information (31) to produce an estimate of the transmit channel.

Abstract: A voltage generation circuit generates a reference voltage using a bandgap reference. A countering circuit is included to adaptively counter for any deviations caused in a bandgap reference voltage such that the reference voltage is independent of fabrication process variations and changes in ambient temperature. In an embodiment, current, proportionate to deviation in absolute value of Vbe from a nominal value, is injected into an emitter-base junction to cause Vbe to equal the nominal value.