Abstract: In one embodiment, an improvement is described for synchronization between devices in, e.g., a wireless network, wherein at least one device includes both a slow clock and a fast clock for different modes of operation. The fast clock for an active mode of operation is calibrated after a sleep mode of operation during which the slow clock is employed for device timing. Calibration employs a filter-based technique. Counts for the slow clock and for the fast clock are measured over a first interval, and the number of slow-clock counts is measured over a second interval. An estimate for the number of fast counts over the second interval is generated, filtered to reduce noise and error effects, and then employed to update the fast clock in the active mode of operation.

Abstract: In an exemplary decision-feedback equalizer (DFE) of a serializer/deserializer (SerDes) receiver, a single current mirror array is shared by multiple current digital-to-analog converter (IDAC) functions. The DFE has an initial amplifier stage that applies an initial coefficient COEFF0 to an input data signal and a number of (e.g., five) additional amplifier stages that apply additional coefficients (e.g., COEFF1-COEFF5) to different delayed versions of the recovered output data stream. The outputs of the initial and multiple additional amplifier stages are summed to generate an equalized data signal that is applied to a clock-and-data recovery (CDR) circuit. Due to certain characteristics of the equalizer function, the multiple additional amplifier stages can be implemented using a single shared current mirror array, which save significant amounts of chip area compared to conventional implementations in which each additional amplifier stage has its own dedicated current mirror array.

Abstract: A medium-reservation mechanism improves transmission efficiency in a multiple-channel network that includes stations with limited-selectivity receivers. The mechanism employs a medium-request signal that conveys channel information. In this network, stations check the channel information in the medium-request signal to decide whether or not to comply with the medium-request signal. If the channel information identifies the channel that is close to the channel that the station is presently operating on, the station then complies with the medium-request signal. If the channel information identifies a channel other than the channel that the station is presently operating on, the station ignores the medium-request signal.

Abstract: In a preferred embodiment, the invention is a mobile communication device having a digital signal processor (DSP), a speaker output node, a local audio source, and an analog front-end (AFE), wherein: (1) the DSP receives a first audio signal corresponding to sound captured by a microphone near a user of the device, (2) if the device is operating in a call mode, the DSP derives a background noise signal from the first audio signal, for subtraction from the first audio signal before transmission to the AFE, and (3) if the device is operating in a non-call mode, then the DSP (i) generates a speaker output signal which substantially corresponds to the first audio signal subtracted from a local audio signal provided by the local audio source and (ii) provides the speaker output signal to a speaker via the speaker output node.

Abstract: In one embodiment, the present invention is a low-density parity-check (LDPC) decoder that has a plurality of variable node units (VNUs) that generate variable node messages and a plurality of check node units (CNUs) that generate check node messages. The variable node messages and check node messages are distributed between the VNUs and CNUs using a number r of combinations of permutators, wherein each permutator combination includes (i) a cyclic shifter and (ii) a fixed, non-cyclic permutator. The cyclic shifters are capable of supporting a number p of different cyclic LDPC sub-matrices; however, when combined with different fixed permutators, the permutator combinations are capable of supporting up to r×p different LDPC sub-matrices. In other embodiments, the LDPC decoder may have fewer than r fixed permutators such that the LDPC decoder is capable of supporting between p and r×p different LDPC sub-matrices.

Abstract: According to one embodiment of the invention, a 16-QAM optical modulator has a Mach-Zehnder modulator (MZM) coupled to a drive circuit that drives the MZM based on two electrical binary signals. The output of the MZM corresponds to an intermediary constellation consisting of four constellation points arranged on a straight line in the corresponding in-phase/quadrature-phase (I-Q) plane. Two of these constellation points correspond to a zero phase, and the remaining two constellation points correspond to a phase of ? radian. The 16-QAM optical modulator further has a phase shifter that modulates the output of the MZM based on two additional electrical binary signals. The resulting optical output signal corresponds to a star 16-QAM constellation, which is produced by incremental rotation of the intermediary constellation.

Abstract: A representative embodiment of the invention provides a thermal actuator for a MEMS-based relay switch. The thermal actuator has an “active” arm that is movably mounted on a substrate. The “active” arm has (i) a thermal expansion layer and (ii) a resistive heater that is electrically isolated from the thermal expansion layer. The thermal expansion layer is adapted to expand in response to a temperature change induced by a control current flowing through the resistive heater, thereby bending the “active” arm and moving that arm with respect to the substrate. Due to the fact that mechanical and electrical characteristics of the “active” arm are primarily controlled by the thermal expansion layer and the resistive heater, respectively, those characteristics can be optimized independently to obtain better operating characteristics for MEMS-based relay switches of the invention compared to those attained in the prior art.

Abstract: A medium-access-control (MAC) scheduler, according to one embodiment of which a station of a wireless network evaluates data throughputs corresponding to three different transmission configurations for transmission of a packet over a first of that station's wireless links. The first and second of those transmission configurations have the packet encoded in the first and second tiers, respectively, of a two-tier signal. The third transmission configuration has the packet encoded as a conventional single-tier signal. For each of the first and second transmission configurations, the station selects a second of that station's wireless links for transmission of at least a second packet, with the first and second packets encoded in different respective tiers of the two-tier signal.

Abstract: In one embodiment, a storage-device-implemented method for estimating one or more channel parameters of a storage device including a read channel and a storage medium with a bit sequence stored on the storage medium. The method includes: (a) the storage device reading at least a portion of the bit sequence from the storage medium to generate a bit response; (b) the storage device convolving the bit response to compute an impulse response of the read channel; and (c) the storage device estimating one or more channel parameters based on the computed impulse response.

Abstract: The present invention enhances the dynamic frequency selection 9DFS) algorithms used in Wireless LANs by adding a channel swapping mechanism. The aim of the traditional DFS algorithm is to dynamically select channels in a wireless LAN in such a way that the best performance is achieved. However, not always the optimal channel selection is achieved. This invention describes an addition to the DFS algorithm in such a way that two APs can decide to swap channels instead of one AP switching to another channel. To avoid the problem of sub-optimal channel selection, a requesting AP sends Swap Requests to other APs in order to sense the willingness of other APs to swap channels with the requesting AP.

Abstract: A wireless receiver detects signals received at two or more antennas, with each antenna coupled to an input receive chain. A switch is employed to couple selected input receive chains to one or more corresponding output receive chains during listening, coarse-detection, and fine-adjustment modes. At least one channel selection filter (CSF) is employed in each output receive chain, and the receiver employs sub-ranging. During idle mode, one antenna's input receive chain is connected to two or more CSFs to detect the packet. When the packet is detected, during a coarse-adjustment mode, the CSFs are reconfigured to couple each antenna's input receive chain to a corresponding output receive chain using low-gain signals. During fine-adjustment mode, the various gains are adjusted to be either high- or low-gain to maintain signals within the dynamic range of the corresponding CSFs.

Abstract: In one embodiment, a wireless power transfer system has a wireless power transmitter and receiver. The transmitter has a transmitting resonant circuit that resonates at a first frequency and a signal generator that generates a signal at a second frequency. The transmitter also has a power detector that measures reflected power at the transmitting resonant circuit, and an auto-tuner that generates transmitter tuning parameters for adjusting the first and second frequencies to reduce reflected power. The receiver has a receiving resonant circuit that resonates at a third frequency based on a receiver tuning parameter. The receiver tuning parameter is generated by a power detector that measures power generated at the receiving resonant circuit, and an auto-tuner that generates the receiver tuning parameter to increase the load power.

Abstract: In accordance with exemplary embodiments, a multi-level flash memory employs error correction of systematic errors when reading multi-level flash memory. Error correction includes i) detection of each systematic error, ii) feedback of the systematic error to circuitry within the memory, and iii) subsequent adjustment within that circuitry to cause a correction of systematic error in the output signal of the multi-level flash memory.

Abstract: In one embodiment, the present invention generates a single rotation angle that may be used to maximize diversity of a quasi-orthogonal space-time block code that encodes groups of four data symbols. Two rotation angles corresponding the first two data symbols in a group are set to zero, and two rotation angles corresponding to the second two data symbols in a group are set to a single initial value. A codeword distance matrix is determined for each possible combination of codewords and erroneously decoded codewords that may be generated using the initial rotation angle, and the minimum of the determinants of these matrices is selected. This process is repeated to generate a plurality of minimum determinants, and, for each iteration, a different single rotation angle corresponding to the second two data symbols is used. Then, a single rotation angle is selected that corresponds to the maximum of the minimum determinants.

Abstract: To ensure that a memory device operates in self-refresh mode, the memory controller includes (1) a normal-mode output buffer for driving a clock enable signal CKE onto the memory device's CKE input and (2) a power island for driving a clock enable signal CKE_prime onto that same input. To power down the memory controller, the normal-mode output buffer drives signal CKE low, then the power island drives signal CKE_prime low, then the memory controller (except for the power island) is powered down. The power island continues to drive the memory device's CKE input low to ensure that the memory device stays in self-refresh mode while the memory controller is powered substantially off. To resume normal operations, the power module powers up the memory controller, then the normal-mode output buffer drives signal CKE low, then the power island is disabled, then the memory controller resumes normal operations of the memory device.

Abstract: A network-equipment-implemented method and apparatus for tracking durations of flows received at a network node in consecutive intervals utilizes two counting bloom filters in ping-pong operation to reduce memory and processing. Identifiers for flows that exceed a predetermined duration or number of intervals are stored in a long-duration flow-identifier table. Hash functions used within the counting bloom filters and optionally used in the long-duration flow-identifier table are chosen to minimize the probability of false positives in the detection of long-duration flows. In some embodiments, flows are sampled to conserve memory and processing resources at the risk of missing detection of some long-duration flows.

Abstract: A method includes storing at least one user datum received from a user in a secure storage portion of a memory within a mobile communication device. Authentication information is received into the mobile communication device. The at least one user datum is transmitted from the mobile communication device to a recipient in response to entry of the authentication information, while preventing the user of the mobile communication device from reading the at least one user datum.

Abstract: A method of using an intercom on a cordless telephone during an active call. The active call is put on hold while the intercom is in use. Once the call is re-activated, the intercom is shut off. This system may be designed for a cordless telephone with one handset or a plurality of handsets.

Abstract: A method and system to permit TV viewers to interact with program content broadcast over a subscriber network, such as cable, satellite, internet, or cellular telephone. The details of the ability for the viewer to interact is embedded as data in the program signal. The subscription provider broadcasts a visual indicator as a small icon during programming that informs the viewer that interaction is permitted. The viewer then uses a remote control to purchase products, vote on events, respond to polls, download files, request information, and request callback actions. The TV viewer uses the remote control to send information to a set-top box front-end application, and to iteratively create transactions that are batched and then sent to a back-end core application and database which then handles fulfillment.

Abstract: In one embodiment, a powered device (PD) (402) has a PHY module (410) and a media access controller (419) (MAC), the PD (402) adapted to connect to power sourcing equipment (PSE) via a cable, (408) where the PD (402) is adapted to communicate with and receive power from the PSE via the cable, in accordance with the Power-over-Ethernet (PoE) standard. The PD (402) extracts (413) from the cable (408) a DC signal used to power the PD without using a transformer. Capacitors (420) located in the signal paths between the MAC (419) and the cable (408) support electrical isolation of the MAC (419).