摘要:
A Unit Element (UE) has a digital X input and a digital W input, and comprises groups of NAND gates generating complementary outputs which are coupled to a differential charge transfer bus comprising a positive charge transfer line and a negative charge transfer line. The number of bits in the X input determines the number of NAND gates in a NAND-group and the number of bits in the W input determines the number of NAND groups. Each NAND-group receives one bit of the W input applied to all of the NAND gates of the NAND-group, and each unit element having the bits of X applied to each associated NAND gate input of each unit element. The NAND gate outputs are coupled through binary weighted charge transfer capacitors to a positive charge transfer line and negative charge transfer line.
摘要:
An optical network includes a transmitting portion configured to (i) encode an input digitized sequence of data samples into a quantized sequence of data samples having a first number of digits per sample, (ii) map the quantized sequence of data samples into a compressed sequence of data samples having a second number of digits per sample, the second number being lower than the first number, and (iii) modulate the compressed sequence of data samples and transmit the modulated sequence over a digital optical link. The optical network further includes a receiving portion configured to (i) receive and demodulate the modulated sequence from the digital optical link, (ii) map the demodulated sequence from the second number of digits per sample into a decompressed sequence having the first number of digits per sample, and (iii) decode the decompressed sequence.
摘要:
In an embodiment, a method includes: receiving an audio frame; decomposing the received audio frame into M sub-band pulse-code modulation (PCM) audio frames, where M is a positive integer number; predicting a PCM sample of one sub-band PCM audio frame of the M sub-band PCM audio frames; comparing the predicted PCM sample with a corresponding received PCM sample to generate a prediction error sample; comparing an instantaneous absolute value of the prediction error sample with a threshold; and replacing the corresponding received PCM sample with a value based on the predicted PCM sample when the instantaneous absolute value of the prediction error sample is greater than the threshold.
摘要:
An encoder includes a low-pass filter to filter input audio signals. The low-pass filter has fixed filter coefficients. The encoder generates quantized signals based on a difference signal. The encoder includes an adaptive quantizer and a decoder to generate feedback signals. The decoder has an inverse quantizer and a predictor. The predictor has fixed control parameters which are based on a frequency response of the low-pass filter. The predictor may include a finite impulse response filter having fixed filter coefficients. The decoder may include an adaptive noise shaping filter coupled between the low-pass filter and the encoder. The adaptive noise shaping filter flattens signals within a frequency spectrum corresponding to a frequency spectrum of the low-pass filter.
摘要:
A signal encoding and compression system with dynamic downsampling may include an encoder module configured to decimate a first digital signal, thereby producing a second digital signal. Each signal may then be DPCM-encoded. Decision logic may then be used to determine which encoded signal to provide as an output, based on a characteristic of the original signal.
摘要:
A sigma delta converter system and method includes a multi bit quantizer circuit coupled to an output of the converter. A single bit analog-to-digital converter circuit is contained in a feedback path of the converter. The converter includes a feed forward path operable to multiply an input voltage by a feed forward coefficient having a value that is a function of a gain control input signal. The gain control input signal can have a value that is a function of the output of the multi bit quantizer.
摘要:
A Multi-stage noise shaping Sigma Delta Modulator (MSDM) and method of processing data using the MSDM are disclosed. The MSDM is capable of operating at high radio frequencies and is characterized by low power consumption, reduced latency and noise and occupies less area in an integrated circuit.
摘要:
The invention relates to a sigma-delta analogue/digital converter for an xDSL multi-standard input stage for converting an xDSL signal into a digital output signal, where the sigma-delta analogue/digital converter (1) has: an analogue loop filter (6) which filters an analogue difference signal between the xDSL signal to be converted and a feedback signal in order to produce a filter output signal; a quantizer which quantizes the filter output signal from the analogue loop filter (6) in order to produce the digital output signal; a first digital/analogue converter (16) which converts the digital output signal into the analogue feedback signal; where the analogue loop filter (6) has at least two resonator filter stages (6a, 6b) which respectively comprise a first integrator (6a-1; 6b-1) and a second integrator (6a-2; 6b-2) connected in series therewith, where the second integrator (6a-2; 6b-2) can be connected to the first integrator (6a-1, 6b-1) by means of a controllable feedback switch (6a-3, 6b-3) in order to close a local feedback loop, where the integrator outputs can respectively be connected by means of a controllable switch (25) to a signal input of an adder (27) which adds the output signals from the integrators in order to produce the filter output signal.
摘要:
A method is provided for multi-channel analog-to-digital conversion. The method includes: receiving an input vector which represents a plurality of analog signals; transforming the input vector using a linear transformation matrix; converting the transformed input vector to a digital stream using an array of sigma-delta converter; and adapting the linear transform matrix to maximize de-correlation between the signals represented in the input vector.
摘要:
The invention relates to a power-saving multibit delta-sigma converter (1) comprising: an input (2) for an analog input signal (ZA) and an output (3) for a digital output signal (ZD); a digital-to-analog converter (4) having a bit width N and serving to convert the digital output signal (ZD) to an analog feedback signal (Z3); a summing device (5) for solving the difference between the input signal (ZA) and the feedback signal (Z3); a filter (6) for filtering the difference signal (Z1); and a clocked quantizing device (7) for quantizing the filtered difference signal (Z2) into a digital output signal (ZD) with the bit width N. Said quantizing device (7) comprises a number of comparators (21, 22, 23) that compare the filtered signal (Z2) with a respective reference potential (U0, U6) associated with each comparator (21, 22, 23) and they each output a comparison result (V1, V2, V3) to a decoder (33), which generates the digital output signal (ZD) from the comparison results (V1, V2, V3), and the reference potentials (U0, . . . U6) are updated according to a previous comparison result.