Abstract: A compressor for waveforms having at least two waveform states separates the waveform samples into waveform state sample vectors for each waveform state. Waveform state encoders encode the waveform state sample vectors separately to provide compressed waveform data. The waveform state encoder selects waveform state pattern vector and associated codes to represent the waveform state sample vectors. The differences between samples of the waveform state sample vector and waveform state pattern vector are calculated and encoded. Encoding can be lossless or lossy. The waveform state pattern vectors and other parameters for compression are determined during a training period. The waveform state encoders detect features in the waveform state sample vectors and waveform state pattern vectors that are useful for common oscilloscope measurements. Typical waveform states include level states and edge states.

Abstract: An enhancement that reduces the digital interface rate of analog-to-digital (A/D) and digital-to-analog (D/A) converters through the use of compression and decompression is described for implementation as a single integrated circuit. Improved A/D converters compressing a sampled version of an A/D converter's analog input signal in real time, thereby significantly decreasing the required bit rate of the A/D converter's digital interface. Similarly, improved D/A converters decrease the required bit rate of the D/A converter's digital interface. D/A converters include a decompressor that decompresses the D/A converter's compressed digital input in real time, prior to conversion to an analog output signal.

Abstract: A data converter includes multiple analog to digital converters (ADCs) and uses a reduced number of data ports at the digital interface for transferring signal samples. The bits of the signal samples generated in parallel by the ADCs are multiplexed into fewer data streams than the number of ADCs. The data ports transfer the data streams at a higher data transfer rate than the bit rate of the samples output from the ADCs. Unused data ports are powered down, decreasing power consumption and system complexity. A host device receives the data streams using fewer input data ports and demultiplexes the received data streams to reproduce the signal samples. Efficient data transfer to a data converter including multiple digital to analog converters (DACs), from a source device generating multiple digital signals can also use fewer data ports having higher data transfer rates.

Abstract: A signal compression method and apparatus for a base transceiver system (BTS) in a wireless communication network provides efficient transfer of compressed signal samples over serial data links in the system. For the uplink, an RF unit of the BTS compresses signal samples resulting from analog to digital conversion of an analog signal received via an antenna. The RF unit transfers the compressed signal samples over the serial data link to the base station processor where they are decompressed prior to the normal signal processing operations. For the downlink, the base station processor compresses signal samples and transfers the compressed signal samples over the serial data link to the RF unit. The RF unit decompresses the compressed samples and converts the decompressed samples to an analog signal for transmission over an antenna. Compression and decompression can be incorporated into operations of conventional base stations and distributed antenna systems.

Abstract: A data converter includes multiple analog to digital converters (ADCs) and uses a reduced number of data ports at the digital interface for transferring signal samples. The bits of the signal samples generated in parallel by the ADCs are multiplexed into fewer data streams than the number of ADCs. The data ports transfer the data streams at a higher data transfer rate than the bit rate of the samples output from the ADCs. Unused data ports are powered down, decreasing power consumption and system complexity. A host device receives the data streams using fewer input data ports and demultiplexes the received data streams to reproduce the signal samples. Efficient data transfer to a data converter including multiple digital to analog converters (DACs), from a source device generating multiple digital signals can also use fewer data ports having higher data transfer rates.

Abstract: In a frequency analysis system, such as a signal detection system or a spectrum analyzer, the frequency domain resolution is enhanced by compression and decompression of the signal samples. The limited capacity of the data storage and/or data transfer resources limit the number of samples that can be stored or transferred. A compressor forms a compressed signal prior to data transfer or storage. A decompressor decompresses the compressed signal prior to transformation to the frequency domain, by a fast Fourier transform or other frequency domain transform. The frequency domain resolution is enhanced because more decompressed samples are available for the frequency domain transform. The compressor and decompressor apply computationally efficient algorithms that can be implemented to operate in real time.

Abstract: Compression of signal samples output from a parallel, time-interleaved analog to digital converter (TIADC) for a baseband signal, includes calculating first or higher order differences of consecutive signal samples followed by lossless or lossy encoding of the difference samples to produce compressed samples. Compression of a TIADC output signal with a nonzero center frequency, includes calculating sums or differences of pairs of signal samples separated by an appropriate number of sampling intervals followed by lossless or lossy encoding. The sums or differences of the signal samples have lower magnitudes than the original samples, allowing more efficient compression. Lossy compression alternatives produce compressed data with a fixed bit rate or with a fixed quality in the decompressed samples.

Abstract: Compression of signal samples output from a parallel, time-interleaved analog to digital converter (TIADC) for a baseband signal, includes calculating first or higher order differences of consecutive signal samples followed by lossless or lossy encoding of the difference samples to produce compressed samples. Compression of a TIADC output signal with a nonzero center frequency, includes calculating sums or differences of pairs of signal samples separated by an appropriate number of sampling intervals followed by lossless or lossy encoding. The sums or differences of the signal samples have lower magnitudes than the original samples, allowing more efficient compression. Lossy compression alternatives produce compressed data with a fixed bit rate or with a fixed quality in the decompressed samples.

Abstract: In a frequency analysis system, such as a signal detection system or a spectrum analyzer, the frequency domain resolution is enhanced by compression and decompression of the signal samples. The limited capacity of the data storage and/or data transfer resources limit the number of samples that can be stored or transferred. A compressor forms a compressed signal prior to data transfer or storage. A decompressor decompresses the compressed signal prior to transformation to the frequency domain, by a fast Fourier transform or other frequency domain transform. The frequency domain resolution is enhanced because more decompressed samples are available for the frequency domain transform. The compressor and decompressor apply computationally efficient algorithms that can be implemented to operate in real time.

Abstract: A compression method and subsystem for a CT scanner compresses projection data from the data acquisition system. The projection data are classified into subsets of more significant samples and subsets of less significant samples. The subsets are compressed in accordance with compression control parameters so that the less significant samples are compressed to a greater degree than the more significant samples. The bit rate of the compressed projection data can be monitored and the compression control parameters can be adjusted to provide a desired bit rate. The compressed data are decompressed in accordance with the compression control parameters for reconstruction of an image from the decompressed projection data. This abstract does not limit the scope of the invention as described in the claims.

Abstract: Control of signal compression is coordinated by selectively modifying control parameters affecting the bit rate, sample rate, dynamic range and compression operations. Selected control parameters are modified according to a control function. The control function can include a ratio parameter that indicates the relative or proportional amounts of change to the control parameters. Alternatively, the control function can be represented in a lookup table with values for the selected control parameters related by the control function. Downsampling the input signal samples according to a sample rate control parameter is followed by upsampling to the original sample rate. Errors are calculated between the upsampled and original signal samples. Encoding of the downsampled signal samples and the error samples is performed in accordance with a compression control parameter. The sample rate control parameter and compression control parameter are determined based on the control function.

Abstract: Compression of signal samples output from a parallel, time-interleaved analog to digital converter (TIADC) for a baseband signal, includes calculating first or higher order differences of consecutive signal samples followed by lossless or lossy encoding of the difference samples to produce compressed samples. Compression of a TIADC output signal with a nonzero center frequency, includes calculating sums or differences of pairs of signal samples separated by an appropriate number of sampling intervals followed by lossless or lossy encoding. The sums or differences of the signal samples have lower magnitudes than the original samples, allowing more efficient compression. Lossy compression alternatives produce compressed data with a fixed bit rate or with a fixed quality in the decompressed samples.

Abstract: An automated test system for a device under test (DUT) compresses the stimulus waveform before transferring it to a storage device or over a data transfer interface. The compressed stimulus waveform data are decompressed, and if required converted to analog form, then applied as a stimulus to the DUT. In response, the DUT produces a response waveform. The response waveform is compressed before transferring it to a storage device or over a data transfer interface. If the response waveform is analog, it is converted to digital before compression. The compressed waveform is decompressed for further analysis or display by a host computer. Features of the response waveform can be calculated from the compressed or uncompressed waveform data. Several configurations that include compression and decompression of stimulus and/or response waveforms in test systems are described.

Abstract: Control of signal compression is coordinated by selectively modifying control parameters affecting the bit rate, sample rate, dynamic range and compression operations. Selected control parameters are modified according to a control function. The control function can include a ratio parameter that indicates the relative or proportional amounts of change to the control parameters. Alternatively, the control function can be represented in a lookup table with values for the selected control parameters related by the control function. The input signal samples can be resampled according to a sample rate control parameter. The dynamic range of signal samples can be selectively adjusted according to a dynamic range control parameter to form modified signal samples. The resampling and dynamic range adjustment can be applied in any order. The modified signal samples are encoded according to a compression control parameter to form compressed samples. The encoder can apply lossless or lossy encoding.

Abstract: Control of signal compression is coordinated by selectively modifying control parameters affecting the bit rate, sample rate, dynamic range and compression operations. Selected control parameters are modified according to a control function. The control function can include a ratio parameter that indicates the relative or proportional amounts of change to the control parameters. Alternatively, the control function can be represented in a lookup table with values for the selected control parameters related by the control function. The input signal samples can be resampled according to a sample rate control parameter. The dynamic range of signal samples can be selectively adjusted according to a dynamic range control parameter to form modified signal samples. The resampling and dynamic range adjustment can be applied in any order. The modified signal samples are encoded according to a compression control parameter to form compressed samples. The encoder can apply lossless or lossy encoding.

Abstract: An automated test system for a device under test (DUT) compresses the stimulus waveform before transferring it to a storage device or over a data transfer interface. The compressed stimulus waveform data are decompressed, and if required converted to analog form, then applied as a stimulus to the DUT. In response, the DUT produces a response waveform. The response waveform is compressed before transferring it to a storage device or over a data transfer interface. If the response waveform is analog, it is converted to digital before compression. The compressed waveform is decompressed for further analysis or display by a host computer. Features of the response waveform can be calculated from the compressed or uncompressed waveform data. Several configurations that include compression and decompression of stimulus and/or response waveforms in test systems are described.

Abstract: A compressor for waveforms having at least two waveform states separates the waveform samples into waveform state sample vectors for each waveform state. Waveform state encoders encode the waveform state sample vectors separately to provide compressed waveform data. The waveform state encoder selects waveform state pattern vector and associated codes to represent the waveform state sample vectors. The differences between samples of the waveform state sample vector and waveform state pattern vector are calculated and encoded. Encoding can be lossless or lossy. The waveform state pattern vectors and other parameters for compression are determined during a training period. The waveform state encoders detect features in the waveform state sample vectors and waveform state pattern vectors that are useful for common oscilloscope measurements. Typical waveform states include level states and edge states.

Abstract: A compressor for waveforms having at least two waveform states separates the waveform samples into waveform state sample vectors for each waveform state. Waveform state encoders encode the waveform state sample vectors separately to provide compressed waveform data. The waveform state encoder selects waveform state pattern vector and associated codes to represent the waveform state sample vectors. The differences between samples of the waveform state sample vector and waveform state pattern vector are calculated and encoded. Encoding can be lossless or lossy. The waveform state pattern vectors and other parameters for compression are determined during a training period. The waveform state encoders detect features in the waveform state sample vectors and waveform state pattern vectors that are useful for common oscilloscope measurements. Typical waveform states include level states and edge states.

Abstract: An enhancement that reduces the digital interface rate of analog-to-digital (A/D) and digital-to-analog (D/A) converters through the use of compression and decompression is described. Improved A/D converters compressing a sampled version of an A/D converter's analog input signal in real time, thereby significantly decreasing the required bit rate of the A/D converter's digital interface. Similarly, improved D/A converters decrease the required bit rate of the D/A converter's digital interface. D/A converters include a decompressor that decompresses the D/A converter's compressed digital input in real time, prior to conversion to an analog output signal.

Abstract: In a frequency analysis system, such as a signal detection system or a spectrum analyzer, the frequency domain resolution is enhanced by compression and decompression of the signal samples. The limited capacity of the data storage and/or data transfer resources limit the number of samples that can be stored or transferred. A compressor forms a compressed signal prior to data transfer or storage. A decompressor decompresses the compressed signal prior to transformation to the frequency domain, by a fast Fourier transform or other frequency domain transform. The frequency domain resolution is enhanced because more decompressed samples are available for the frequency domain transform. The compressor and decompressor apply computationally efficient algorithms that can be implemented to operate in real time.