Abstract: A technique for performing AGC and DC compensation in a receiver. The receiver comprises an energy estimator for generating an estimate of the level of a received signal; an RF device to apply gain to the received signal; an AGC for controlling the RF device gain based on the energy estimation; a first DC compensation loop for finely adjusting the DC component of the received signal in fast or slow tracking mode (FTM or STM); and a second DC compensation loop for coarsely adjusting the DC component of the received signal. Three modes of AGC operations: In Acquisition, iterations of FTM fine DC adjustment, short energy estimation, and RF device gain adjustment are performed during signal timing detection. In Connected, long energy estimation, RF device gain adjustment, and STM fine and coarse DC adjustments are performed during superframe preamble. In Sleep, FTM fine DC adjustment, short energy estimation, and RF device gain adjustment are performed during superframe preamble.

Abstract: While taking X-Y coordinate measurements to determine the location of a point of contact on a touch screen, a controller circuit drives the touch screen with a selectable voltage. Voltages output from the touch screen are converted by an ADC into the X-coordinate and Y-coordinate values. The ADC has a convertible input voltage range. If only a low touch screen detection resolution is required, then the voltage with which the touch screen is driven is made to be substantially less than the convertible input voltage range. Only a portion of the convertible input range is usable, but this is adequate for the application and power consumption is reduced. If a higher touch screen detection resolution is required, then the touch screen is driven with a higher voltage. Power consumption is increased, but more or all of the convertible input voltage range of the ADC is then usable.

Abstract: The present patent application discloses a method and apparatus for decoding, comprising decoding signals iteratively, mutually exchanging extrinsic information, calculating APP LLRs for both systematic and parity bits and making a hard decision after a plurality of iterations is completed based on accumulated soft information. The present patent application also discloses a method and apparatus for post decoding soft interference canceling, comprising generating updated a posteriori probabilities for systematic and parity bits from a turbo decoder, mapping the posteriori probabilities to soft symbols, quantizing the soft symbols, re-encoding a data packet, filtering a chip sequence, reconstructing an interference waveform, and scaling reconstruction filter coefficients using the symbols.

Abstract: A novel and improved method and system for paging a cellular telephone or other wireless terminal using two paging channels that reduces standby mode power consumption described. In one embodiment of the invention, a minimally encoded quick paging channel is established over which short, quick page messages are transmitted during one of a set of quick paging slots. The quick page message indicates that a communications request has been received, and that the receiving communication terminals should process a highly encoded full paging channel over which more detailed, full page messages are transmitted during the next full paging slot. A terminal monitors full paging channel only after a quick page message has been received on the quick paging channel.

Abstract: Systems and methods are provided to generate a set of synchronization channel sequences that optimize time and frequency acquisition. A set of root indices of Zadoff-Chu sequences in a first domain (e.g., time domain) that optimize a performance metric or merit factor are identified. An optimal index is determined that also optimizes a performance metric in a reciprocal domain (e.g., frequency domain). Optimal indices satisfy a centro-symmetric relationship with respect to a half-value of sequence length: When 1 is an optimal index, N?1 is also an optimal root index. For sequences of length Q2=N, a base sequence generated with an optimal sequence can be utilized to generate at least two disparate optimal sequences through sign-flip, conjugation, and periodic modulation operations.

Abstract: In embodiments, a fast Fourier transform (FFT) engine includes a series of stages, each stage containing a butterfly and a data normalization device configured to scale output of the stage's butterfly. The scaling factors are adjusted, for example, periodically or on as-needed basis, so that the dynamic range of the butterflies and the buffers is increased for a given bit-width, or the bit-width of these devices is decreased for the same dynamic range. Additionally, bit-width of other buffer(s) is decreased because of the scaling of the data.

Abstract: A reference signal management (RSM) program executing on a mobile device detects multiple reference signals, allocates those reference signals into groups, and performs reference signal management functions using information conveyed in the reference signals. The RSM program detects both broadband and narrowband reference signals and maintains updated groups of reference signals that are transmitted from access points with independent configurations or different radio technologies. Battery power of the mobile device is efficiently used to manage reference signals in heterogeneous network environments by preventing unnecessary handoffs, overhead downloads, access probes and new registrations. Reference signals are managed from both synchronous and asynchronous sectors and in idle mode as well as in connected state mode.

Abstract: Systems and methods for canceling interference in a communication system are described. A signal that comprises current data from a current access point and secondary data from one or more secondary access points is received. The secondary data is demodulated using one or more secondary channel estimates if a signal metric is less than a predetermined threshold. Interference in the received signal is canceled using the demodulated secondary data if the signal metric is less than the predetermined threshold. The received signal with the interference canceled is demodulated using a current channel estimate to obtain the current data. The method for interference cancellation may use the same hardware resources and processing available for receiving data from a single access point.

Abstract: A method for adjusting timing in a Frequency Division Multiplexing (FDM) system, including receiving a request to perform a timing correction, generating a time domain FDM symbol, and controlling the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.

Abstract: Techniques for performing equalization at a receiver are described. In an aspect, equalization is performed by sub-sampling an over-sampled input signal to obtain multiple sub-sampled signals. An over-sampled channel impulse response estimate is derived and sub-sampled to obtain multiple sub-sampled channel impulse response estimates. At least one set of equalizer coefficients is derived based on at least one sub-sampled channel impulse response estimate. At least one sub-sampled signal is filtered with the at least one set of equalizer coefficients to obtain at least one output signal. One sub-sampled signal (e.g., with largest energy) may be selected and equalized based on a set of equalizer coefficients derived from an associated sub-sampled channel impulse response estimate. Alternatively, the multiple sub-sampled signals may be equalized based on multiple sets of equalizer coefficients, which may be derived separately or jointly.

Abstract: Techniques for transmitting signaling information for broadcast and multicast services are described. A base station transmits signaling information for each service in accordance with a schedule that includes a repetition period and a modification period. The signaling information is sent in each repetition period to allow wireless devices to quickly obtain this information. Changes to the critical signaling information are permitted at the start of each modification period, which is an integer multiple of the repetition period. Whenever the critical signaling information for a given service is changed in a given modification period, a notification indicator for the service is set in an entire preceding modification period to inform the wireless devices of the impending change. The wireless devices can detect the notification indicator being set in the preceding modification period and can retrieve the updated critical signaling information in the following modification period.

Abstract: Techniques for transmitting and receiving data in an efficient manner to potentially improve capacity for a wireless network and achieve power savings for a wireless device are described. The techniques utilize a Continuous Packet Connectivity (CPC) mode comprised of multiple (e.g., two) discontinuous transmission (DTX) modes and at least one (e.g., one) discontinuous reception (DRX) mode. Each DTX mode is associated with different enabled uplink subframes usable for transmission from the wireless device to the network. Each DRX mode is associated with different enabled downlink subframes usable by the network for transmission to the wireless device. The wireless device may send signaling and/or data on the enabled uplink subframes and may receive signaling and/or data on the enabled downlink subframes. The wireless device may power down during non-enabled subframes to conserve battery power. Mechanisms to quickly transition between the DTX and DRX modes are described.

Abstract: A method and apparatus for transmitting broadcast information in a multi-carrier communication system. The Sync Channel of the multi-carrier system is transmitted a 1.25 MHz channel bandwidth (i.e., over a single carrier), and to specify the preferred channels for the Sync Channel transmission instead of the preferred channels for the entire multi-carrier system. The Sync Channel Message will carry additional information indicating the center frequency of a multi-carrier system within a reserved set of frequency bands and indicating the frequency of a single carrier system in the reserved set of frequency bands. Considering the A block of the PCS band again, the preferred channels for Sync Channel transmission can be selected as channels 75, 150 and 225. This selection ensures that one of the preferred channels will always be used by any multi-carrier system regardless of the location of its center channel.

Abstract: A system and method are disclosed related to calibrating a power-on gating window for a time-to-digital converter (TDC) of a digital phase locked loop (DPLL). The gating window is calibrated to ensure proper operation of the DPLL, while at the same time operating the TDC in a power efficient manner. In particular, the technique entails setting the width of the TDC gating window to a default value; operating the DPLL until the control loop is substantially locked; decreasing the width of the TDC gating window by a predetermined amount, while monitoring the phase error signal generated by the phase error device of the DPLL; determining the current width of the TDC gating window at substantially a time when the phase error arrives at or crosses a predetermined threshold; and increasing the current width of the TDC gating window by a predetermined amount to build in a margin of error for the operating width of the TDC gating window.

Abstract: To transmit overhead information for broadcast and multicast services in a system that utilizes multiple radio technologies, time slots used for OFDM in a super-frame are initially ascertained. Overhead information for multiple streams to be sent in the time slots used for OFDM is generated. The overhead information conveys the time slots and the coding and modulation used for the streams and may be given in various forms. Multiple records may be formed for the overhead information for the streams. The overhead information for the streams is processed and time division multiplexed with the data for the streams in the super-frame. Information indicating the time slots used for OFDM in the super-frame may be sent separately or included in the overhead information. An indicator may also be appended to each stream to indicate whether there is any change in the overhead information for the stream in the next super-frame.

Abstract: A technique for generating a reduced bit-width in a signal generated by a first-type modulator in a communication apparatus that includes two distinct modulators. In particular, the communication apparatus includes a first modulator adapted to generate a first modulated signal quantified to a first bit-width, a second modulator adapted to generate a second modulated signal quantified to a second bit-width that is less than the first bit-width, and a device to generate a third modulated signal comprising a combination of the first and second modulated signals. In an exemplary implementation, the first modulator includes an OFDMA modulator, the second modulator includes a CDMA, and the combining device includes an IFFT.

Abstract: In one aspect, a digital PLL (DPLL) operates based on fractional portions of input and output phases. The DPLL accumulates at least one input signal to obtain an input phase. The DPLL determines a fractional portion of an output phase based on a phase difference between an oscillator signal from an oscillator and a reference signal, e.g., using a time-to-digital converter (TDC). The DPLL determines a phase error based on the fractional portion of the input phase and the fractional portion of the output phase. The DPLL then generates a control signal for the oscillator based on the phase error. In another aspect, a DPLL includes a synthesized accumulator that determines a coarse output phase by keeping track of the number of oscillator signal cycles based on the reference signal.

Abstract: Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed.

Abstract: Selectable sizes for a local oscillator (LO) buffer and mixer are disclosed. In an embodiment, LO buffer and/or mixer size may be increased when a receiver operates in a high gain mode, while LO buffer and/or mixer size may be decreased when the receiver operates in a low gain mode. In an embodiment, LO buffer and mixer sizes are increased and decreased in lock step. Circuit topologies and control schemes for specific embodiments of LO buffers and mixers having adjustable size are disclosed.

Abstract: A method for calibrating the loop bandwidth of a phase-locked loop (PLL) is described. At least one resistor in the PLL filter is tuned in accordance with the frequency of an input reference signal. One or more capacitors in the PLL filter are tuned in accordance with the frequency of the input reference signal. Output pulses of one or more voltage controlled oscillators (VCO) are counted. A first charge pump current associated with a target loop bandwidth is counted in accordance with the counted output pulses. A programmable charge pump current is tuned to the calculated first charge pump current.