Abstract: Techniques for dithering quantization thresholds of time-to-digital converters (TDC's) in all-digital phase-locked loops (ADPLL's) are disclosed. In an embodiment, the delay introduced by an individual buffer in a TDC delay line may be dithered. In another embodiment, the delay associated with the TDC delay line may be extended by a fixed amount to accommodate dithering of the zero-delay threshold.

Abstract: Techniques for generating oscillator signals in a wireless communication device are described. A phase-locked loop (PLL) may be used to generate an oscillator signal for a selected frequency channel. Different PLL settings may be used for the blocks in the PLL for different frequency channels. The different PLL settings may be for different PLL loop bandwidths, different amounts of charge pump current, different frequency equations associated with different sets of high and low divider ratios, different frequency division schemes associated with different prescaler ratios and/or different integer divider ratios, high side or low side injection for a super-heterodyne receiver or transmitter, and/or different supply voltages for one or more circuit blocks such as an oscillator. A suitable set of PLL settings may be selected for each frequency channel such that adverse impact due to spurs can be mitigated.

Abstract: A downconversion mixer includes a configurable gate or bulk bias voltage to allow calibration and correction of device offsets. Calibration may be performed on the configurable bias voltages to minimize IM2 distortion in the mixer. The techniques have minimal impact on voltage headroom, impose no requirement for a signal path to be phase-matched with a calibration path, and are particularly well-suited for passive mixers.

Abstract: A method for automatically tuning a frequency modulator in a mobile device is described. A frequency band is automatically scanned using a frequency modulation (FM) receiver. The FM receiver is integrated as a part of the mobile device. Quality associated with channels of the frequency band is analyzed to identify at least one available channel at a first frequency. The first frequency is assigned to an FM modulator. The FM modulator is integrated as a part of the mobile device. A determination is made whether a command to scan for a second frequency is received. If the command to scan for the second frequency is not received, a signal on the first frequency is transmitted by the FM modulator.

Abstract: A phase to digital converter, all digital phase locked loop, and apparatus having an all digital phase locked loop are described herein. The phase to digital converter includes a phase to frequency converter driving a time to digital converter. The time to digital converter determines a magnitude and sign of the phase differences output by the phase to frequency converter. The time to digital converter utilizes tapped delay lines and looped feedback counters to enable measurement of small timing differences typical of a loop tracking process and large timing differences typical of an loop acquisition process. The tapped delay lines permit the measurement of fractions of a reference period and enable lower power operation of the phase to digital converter by reducing requirements on the speed of the reference clock.

Abstract: In one embodiment of the invention, a method for a charge pump is disclosed. The method includes biasing a plurality of transistors; switching a pair of main transistor switches to apply or remove a net charge on an output terminal though the biased transistors; and turning on auxiliary transistor switches when the main transistor switches are turned off. The auxiliary transistor switches when turned on provide an auxiliary equalizing path to nodes between the main transistor switches and the biased transistors. The auxiliary equalizing path equalizes voltages between the intermediate nodes to rapidly turn off the biased transistors and reduce noise on the output terminal of the charge pump.

Abstract: Techniques for filtering noisy estimates to reduce estimation errors are described. A sequence of input values (e.g., for an initial channel impulse response estimate (CIRE)) is filtered with an infinite impulse response (IIR) filter having at least one coefficient to obtain a sequence of output values (e.g., for a filtered CIRE). The coefficient(s) are updated based on the sequence of input values with an adaptive filter, a bank of prediction filters, or a normalized variation technique. To update the coefficient(s) with the adaptive filter, a sequence of predicted values is derived based on the sequence of input values. Prediction errors between the sequence of predicted values and the sequence of input values are determined and filtered to obtain filtered prediction errors. The coefficient(s) of the IIR filter are then updated based on the prediction errors and the filtered prediction errors.

Abstract: A method and apparatus for acknowledging reverse link transmissions in a communications system. An information bit is set and then repeated. The repeated information bit is covered with a code having a frame length defined by S=M*N*R, where S is the frame length, M is the number of code symbols per slot, N is the number of slots per frame, and R is the code repetition factor. The gain is then set relative to a power control transmission and the frames resulting from the coding operation are then modulated. After modulation, the result is spread on a designated channel using quadrature spreading and after spreading the acknowledgement is transmitted over the reverse link.

Abstract: A differential low noise amplifier (LNA) involves two main amplifying transistors biased in saturation, and two cancel transistors biased in sub-threshold. In one example, the gates of the cancel transistors are coupled to the drains of main transistors, in a symmetrical and cross-coupled fashion. The main transistors are source degenerated. Because the gates of cancel transistors are not coupled to the differential input leads of the LNA, the input capacitance of the LNA is reduced. Noise introduced into the LNA output due to the cancel transistors being biased in the sub-threshold region is reduced because there are two stages. The first stage involves the main transistors, and the second stage involves the cancel transistors. By increasing the gain of the first stage and decreasing the gain of the second stage, overall LNA gain is maintained while reducing the noise that the sub-threshold biased transistors contribute to the LNA output.

Abstract: Frame structures and transmission techniques for a wireless communication system are described. In one frame structure, a super-frame includes multiple outer-frames, and each outer-frame includes multiple frames, and each frame includes multiple time slots. The time slots in each super-frame are allocated for downlink and uplink and for different radio technologies (e.g., W-CDMA and OFDM) based on loading. Each physical channel is allocated at least one time slot in at least one frame of each outer-frame in the super-frame. An OFDM waveform is generated for each downlink OFDM slot and multiplexed onto the slot. A W-CDMA waveform is generated for each downlink W-CDMA slot and multiplexed onto the slot. A modulated signal is generated for the multiplexed W-CDMA and OFDM waveforms and transmitted on the downlink. Each physical channel is transmitted in bursts. The slot allocation and coding and modulation for each physical channel can change for each super-frame.

Abstract: Embodiments disclosed herein relate to methods and systems for providing improved position-location (e.g., time-of-arrival) measurement and enhanced position location in wireless communication systems. In an embodiment, an access point may replace information (e.g., data) transmission by a “known” transmission (or “reference transmission”) at a predetermined time known to access terminals in the corresponding sectors. The access terminals may use the received reference transmission to perform a position-location measurement, and report back the measured information. The access point may also send a reference transmission on demand, e.g., in response to a request from an access terminal in need for a location-based service.

Abstract: A bi-polar modulator that can perform quadrature modulation using amplitude modulators is described. In one design, the bi-polar modulator includes first and second amplitude modulators and a summer. The first amplitude modulator amplitude modulates a first carrier signal with a first input signal and provides a first amplitude modulated signal. The second amplitude modulator amplitude modulates a second carrier signal with a second input signal and provides a second amplitude modulated signal. The summer sums the first and second amplitude modulated signals and provides a quadrature modulated signal that is both amplitude and phase modulated. The first and second input signals may be obtained based on absolute values of first and second modulating signals, respectively. The first and second carrier signals have phases determined based on the sign of the first and second modulating signals, respectively. Each amplitude modulator may be implemented with a class-E amplifier.

Abstract: Techniques for transmitting data in a manner to facilitate equalization at a receiver are described. Guard intervals are appended to data blocks such that each data block has a guard interval at the beginning of the data block and a guard interval at the end of the data block. Each guard interval may be discontinuous transmission (DTX), a polyphase sequence, or some other known sequence. Pilot is appended to each set of at least one data block. The data blocks, pilot, and guard intervals may be sent using various slot structures and are processed for transmission. The processing may include mapping the data blocks to at least one physical channel, channelizing the data blocks for each physical channel with a channelization code, combining all physical channels, and scrambling the combined data, pilot, and guard intervals with a scrambling code.

Abstract: Techniques for deriving sample timing for multiple signal instances received on multiple antennas for a given propagation path. In one scheme, a DLL is maintained for each path, and each DLL tracks the timing of the best signal instance for the assigned path. In another scheme, a DLL is maintained for each path, and each DLL tracks the average timing of the multiple signal instances for the assigned path. To reduce timing jitter, the SINR of a signal instance may be estimated for a number of different time offsets. The loop filter for the DLL is initially updated in the normal manner. If a change in the time offset used for the sample timing is detected, then the SINRs for the new and prior offsets are compared. The new time offset is used if the associated SINR is better. Otherwise, the prior time offset is retained and used.

Abstract: A Method and System for Utilization of an Outer Decoder in a Broadcast Services Communication System is described. An outer decoder and an inner decoder encode a block of information to be transmitted, to improve protection by adding redundancy. The redundancy permits decoding of the information from less than a complete encoded block of information. Consequently, the receiving station determines when sufficient amount of information for successful decoding has been received, and utilizes the time remaining before the next block of information arrives to perform other activities, e.g., hard handoff on a broadcast channel, inter-frequency hard handoff, and other activities. Alternatively, the receiving station can cease reception, thus decrease power consumption. Furthermore, part of the information block may be utilized for transmission of signaling information.

Abstract: Techniques to compensate for nonlinearity of a tuning function of an oscillator are described. The tuning nonlinearity of the oscillator may be modeled as a disturbance input to the oscillator and may be compensated with an equal but opposite disturbance. In one design, a nonlinearity correction signal to compensate for the tuning nonlinearity may be generated, e.g., based on a phase error signal in a phase-locked loop (PLL) and a scaling factor determined adaptively. The nonlinearity correction signal may compensate for the n-th (e.g., second) order tuning nonlinearity, and an n-th order (e.g., squared) modulating signal may be used to derive the scaling factor and the nonlinearity correction signal. A control signal for the oscillator may be generated based on the nonlinearity correction signal and possibly one or more other signals. The control signal may be applied to the oscillator to adjust the oscillation frequency of the oscillator.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve communicating over a physical channel having a plurality of modulation channels each having a channel capacity by allocating a plurality of data streams among the modulation channels as a function of the channel capacity for each of the modulation channels, and modulating the data streams to support transmission over the physical channel as a function of the data stream allocation among the modulation channels. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: Method and apparatus for high rate code-division multiple access wireless communication is described. Each of a channel encoded data is modulated by an associated code having a small number of pseudo-noise spreading chips per orthogonal waveform period, thus producing a set of streams of modulated symbols. Each of the set of streams of modulated symbols is then gain adjusted, and combined to yield two streams of combined symbols. The combination is the set of streams is carried out to reduce a peak-to-average ratio of the transmission. The resulting two combined symbol streams are modulated by a complex multiplier using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission.

Abstract: Method and apparatus for generating codewords with variable length and redundancy from a single Low-Density Parity-Check (LDPC) code with variable length input words. A mother code for encoding data words is generated based on a parity-check matrix, wherein the mother code is adjusted to reflect the size of the data word to be encoded. A generator matrix applies the mother code to data words to produce codewords for transmission. In one embodiment, a reduction criteria is determined and the size of the generator matrix reduced in response. The corresponding parity-check matrix is applied at the receiver for decoding the received codeword.

Abstract: The present invention describes a spread spectrum communication system wherein the frequency of carriers and the code channels of the carriers or both for transmission to a given remote station user vary in time. This provides for a direct sequence spectrum communications system which changes frequency or code channel according to a predetermined pattern. The code channels and frequencies can be determined in accordance with a deterministic function or based upon a subset of the data to be transmitted. A receiver structure is also described for receiving the same.