Abstract: The invention provides a method for gain error estimation in an analog-to-digital converter. In one embodiment, the analog-to-digital converter comprises a plurality of stages. A series of correction numbers applied to a target stage selected from the stages are correlated with a series of calculation values calculated according to digital output values of the stages to generate a series of gain error estimates. The series of gain error estimates are multiplied by a series of updating parameters to obtain a series of first values. A series of previous gain error values are multiplied by one minus the corresponding updating parameters to obtain a series of second values, wherein the series of previous gain values are obtained by delaying the present gain error values. The series of first values and the series of second values are correspondingly added to obtain a series of present gain error values for gain error correction.

Abstract: The invention provides a method for gain error estimation in an analog-to-digital converter. In one embodiment, the analog-to-digital converter comprises a plurality of stages. A series of correction numbers applied to a target stage selected from the stages are correlated with a series of calculation values calculated according to digital output values of the stages to generate a series of gain error estimates. The series of gain error estimates are multiplied by a series of updating parameters to obtain a series of first values. A series of previous gain error values are multiplied by one minus the corresponding updating parameters to obtain a series of second values, wherein the series of previous gain values are obtained by delaying the present gain error values. The series of first values and the series of second values are correspondingly added to obtain a series of present gain error values for gain error correction.

Abstract: The invention provides a method for gain error estimation for an analog-to-digital converter. In one embodiment, the analog-to-digital converter comprises a plurality of stages. First, a series of correction numbers applied to a target stage selected from the stages are correlated with a series of first values calculated according to digital output values of the stages to generate a series of gain error estimates. Every first number of the series of gain error estimates is then averaged to obtain a series of second values. A second number of the series of second values is then averaged to obtain a gain error of the target stage.

Abstract: The invention provides an analog-to-digital converter (ADC). The ADC comprises a plurality of stages connected in series, a gain error correction module, and a look-ahead module. Each of the stages derives a stage output value from a stage input signal and generates a stage output signal as the stage input signal of a subsequent stage, wherein one of the stages is selected as a target stage for estimating a gain value thereof. The gain error correction module delivers a correction number to the target stage to affect the stage output signal of the target stage and the stage output values of subsequent stages of the target stage, receives at least one auxiliary output value from a look-ahead module dedicated to the target stage, and derives an error estimate of the gain value of the target stage from the stage output values and the auxiliary output value.

Abstract: The invention provides a method of gain error calibration in a pipelined analog-to-digital converter (ADC). In one embodiment, a first stage and a second stage of the pipelined ADC share a common operational amplifier. The first stage is requested to generate the stage output signal thereof according to a first correction number. The second stage is also requested to generate the stage output signal thereof according to a second correction number. A plurality of stage output values generated by stages of the pipelined ADC are collected. The stage output values are respectively correlated with the first correction number and the second correction number to estimate a first gain error estimate of the first stage and a second gain error estimate of the second stage. The first gain error estimate and the second gain error estimate are weighted to obtain a predicted gain error for gain error calibration in the first stage and the second stage.

Abstract: An AV playback method for an interactive mechanism includes generating a designated file comprising a plurality of data created by a user and playback information comprising a play time and a display location of the data of the designated file, storing the designated file in a storage device through an interface provided by a first player, and the first player displaying each data in the designated file according to the corresponding play time and the display location indicated by the playback information while playing the multimedia film simultaneously. The data in the designated file is only displayed while the multimedia film is played, making no substantial change to the multimedia file itself.

Abstract: Methods and apparatus for out of service processing with varied behaviors. In an aspect, a method is provided for service acquisition. The method includes determining one or more conditions, wherein each condition is associated with at least one weight, detecting whether an out-of-service event has occurred, and if an out-of-service event is detected: identifying selected conditions and associated weights, and processing the associated weights to determine service acquisition “on” and “off” times. In an aspect, an apparatus includes condition logic configured to determine one or more conditions, wherein each condition is associated with at least one weight, and processing logic configured to detect whether an out-of-service event has occurred, and if an out-of-service event is detected, to identify selected conditions and associated weights, and process the associated weights to determine service acquisition “on” and “off” times.

Abstract: A method for tuning a filter is provided. The method includes: enabling a VCO circuit, wherein at least a portion of the VCO circuit is selected from the filter; generating an oscillation signal by the VCO circuit according to a driving signal; comparing the oscillation signal with a reference signal and generating a comparison result; and adjusting the driving signal according to the comparison result.

Abstract: A tuning method and a tuning apparatus for tuning a filter are disclosed. The tuning method includes: configuring the filter as a VCO; utilizing the VCO to generate an oscillation signal according to a driving signal; comparing a frequency of the oscillation signal with a reference frequency to generate a comparison result; converting the comparison result into the driving signal in order to establish a feedback mechanism. Therefore, the inner components such as the gm and capacitance inside the VCO are completely tuned when the VCO generates an oscillation signal having a wanted frequency. Since the VCO is inside the filter and the components of the filter and the VCO are similar, the driving signal can be utilized to make the filter operate in a desired center frequency under a well-designed relationship between the frequency of the oscillation signal and the center frequency.

Abstract: Variable gain amplifiers with wider linear range are provided, in which first and second loads are coupled to a power voltage, and a transconductor cell comprises first and second transistors, a gain control transistor, and first and second current sources. The first and second transistors comprise control terminals receiving a set of input signals, first terminals coupled to the first and second loads respectively, and second terminal coupled to first and second nodes respectively. The first and second current sources are coupled between the first node and a first voltage and between the second node and the first voltage respectively. The first gain control transistor is coupled between the first node and second node, receiving a gain control voltage, in which the grain control transistor has a threshold voltage lower than that of the first and second transistors.

Abstract: A Delta-Sigma DAC is provided, comprising an interpolator, a Delta-Sigma modulator, a FIR filter and an analog filter. The interpolator oversamples a n-bit digital signal to generate a n-bit oversampled signal. The Delta-Sigma modulator coupled to the output of interpolator shapes the n-bit oversampled digital signal to generate a shaped digital signal. The FIR filter coupled to the Delta-Sigma modulator filters the shaped digital signal to generate an analog audio signal. The analog filter coupled to the FIR filter amplifies the analog audio signal to generate a audible signal.

Abstract: Techniques for dynamically selecting warm-up time for a wireless device operating in the idle mode are described. At each active interval, conditions affecting warm-up of the wireless device at a next active interval are determined. The conditions may pertain to channel conditions, operating conditions, and/or hardware configuration. A warm-up time is selected based on the determined conditions. A wake-up time for the next active interval is determined based on the selected warm-up time. The wireless device then goes to sleep until the wake-up time. In one scheme, the strongest pilot acquired in each active interval is identified, and its pilot strength is averaged to obtain an average pilot strength. The average pilot strength is compared against at least one threshold, and one of at least two possible time durations is selected for the warm-up time based on the comparison result.

Abstract: An automatic gain control apparatus receiving an analog signal and outputting a digital signal includes a variable gain amplifier, an A/D converter, and a feedback circuit. The variable gain amplifier amplifies the analog signal with a gain. The A/D converter converts the amplified analog signal to the digital signal. The feedback circuit includes an amplitude level detector, a range detector, and a gain controller. The amplitude level detector generates a first amplitude level and a second amplitude level in response to the digital signal. The range detector generates an adjustment signal in response to the first amplitude level and the second amplitude level. The gain controller adjusts a gain control level for the variable gain amplifier in response to the adjustment signal.

Abstract: An automatic gain control apparatus receiving an analog signal and outputting a digital signal includes a variable gain amplifier, an A/D converter, and a feedback circuit. The variable gain amplifier amplifies the analog signal with a gain. The A/D converter converts the amplified analog signal to the digital signal. The feedback circuit includes an amplitude level detector, a range detector, and a gain controller. The amplitude level detector generates a first amplitude level and a second amplitude level in response to the digital signal. The range detector generates an adjustment signal in response to the first amplitude level and the second amplitude level. The gain controller adjusts a gain control level for the variable gain amplifier in response to the adjustment signal.

Abstract: A Delta-Sigma DAC is provided, comprising an interpolator, a Delta-Sigma modulator, a FIR filter and an analog filter. The interpolator oversamples a n-bit digital signal to generate a n-bit oversampled signal. The Delta-Sigma modulator coupled to the output of interpolator shapes the n-bit oversampled digital signal to generate a shaped digital signal. The FIR filter coupled to the Delta-Sigma modulator filters the shaped digital signal to generate an analog audio signal. The analog filter coupled to the FIR filter amplifies the analog audio signal to generate a audible signal.

Abstract: A tuning method and a tuning apparatus for tuning a filter are disclosed. The tuning method includes: configuring the filter as a VCO; utilizing the VCO to generate an oscillation signal according to a driving signal; comparing a frequency of the oscillation signal with a reference frequency to generate a comparison result; converting the comparison result into the driving signal in order to establish a feedback mechanism. Therefore, the inner components such as the gm and capacitance inside the VCO are completely tuned when the VCO generates an oscillation signal having a wanted frequency. Since the VCO is inside the filter and the components of the filter and the VCO are similar, the driving signal can be utilized to make the filter operate in a desired center frequency under a well-designed relationship between the frequency of the oscillation signal and the center frequency.

Abstract: A wireless device detects for an adverse channel condition, which may be (1) a frequent out of service (FOOS) condition indicative of frequent in and out of service or (2) an unbalanced forward/reverse link condition indicative of unbalanced coverage for the forward and reverse links. A FOOS condition may be detected based on an average in-service time, the number of lost system connections, the number of systems to which connections have been made, the rate of change for the systems, the altitude of the wireless device, and/or other parameters. An unbalanced forward/reverse link condition may be detected based on the average in-service time, the number of system access failures, and/or other parameters. The wireless device performs at least one action to conserve battery power if an adverse channel condition is detected. The action(s) may include performing system acquisition less frequently, disabling system registration, performing registration less frequently, and/or going to sleep.

Abstract: Embodiments include a method of signal processing in which each of a set of individual estimates of a transmitted symbol is added to a combined symbol estimate based on a relation between a signal quality value corresponding to the individual estimate and a threshold value, where the threshold value is based on a maximum among the signal quality values.

Abstract: A method for calculating a metric indicating a symmetry of a signal waveform includes inverting the signal waveform to produce an inverted signal waveform; measuring a first set of peak, bottom, and average values corresponding to the signal waveform by detecting a peak value of the signal waveform, detecting a bottom value of the signal waveform, and detecting an average value of the signal waveform; measuring a second set of peak, bottom, and average values of the inverted signal waveform by detecting a peak value of the inverted signal waveform, detecting a bottom value of the inverted signal waveform, and detecting an average value of the inverted signal waveform; and calculating the metric indicating the symmetry of the signal waveform according to the first set of peak, bottom, and average values of the signal waveform, and the second set of peak, bottom, and average values of the inverted signal waveform.

Abstract: The standby time of a CDMA cell phone is extended by using two receive chains to monitor the Quick Paging Channel (QPCH) when the signal-to-noise ratio falls within a predetermined range. Monitoring the QPCH saves battery power by obviating the need to monitor the general paging message unless quick paging (PI) bits are set. The QPCH is not monitored, however, in noisy environments where PI bits are incorrectly detected causing the paging message to be needlessly monitored. Power is saved by monitoring the QPCH in noisier environments without increasing the incorrect detection rate. Incorrect detection is reduced in the predetermined range by using an additional receive chain to achieve receive diversity. Although additional power is consumed by the second receive chain in the predetermined range, the power saved by not demodulating the paging message at each slot more than compensates for the additional power consumed by the second receive chain.