| Patent application number | Description | Published |
|---|
| 20080243408 | DATA COMPRESSION FOR A WAVEFORM DATA ANALYZER - 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. | 10-02-2008 |
| 20090073006 | ENHANCED CONTROL FOR COMPRESSION AND DECOMPRESSION OF SAMPLED SIGNALS - 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. | 03-19-2009 |
| 20090113266 | COMPRESSION AND DECOMPRESSION OF STIMULUS AND RESPONSE WAVEFORMS IN AUTOMATED TEST SYSTEMS - 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. | 04-30-2009 |
| 20090160685 | ENHANCED CONTROL FOR COMPRESSION AND DECOMPRESSION OF SAMPLED SIGNALS - 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. | 06-25-2009 |
| 20090169119 | COMPRESSION AND DECOMPRESSION OF COMPUTED TOMOGRAPHY DATA - 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. | 07-02-2009 |
| 20090201181 | ENHANCED TIME-INTERLEAVED A/D CONVERSION USING COMPRESSION - 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. Alternatives for lossy compression include attenuating the analog signal before sampling by the TIADC, applying bit shifters or multipliers after sampling to reduce the magnitudes of the signal samples, and lossy encoding. | 08-13-2009 |
| 20090201182 | ENHANCED TIME-INTERLEAVED A/D CONVERSION USING COMPRESSION - 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. Alternatives for lossy compression include attenuating the analog signal before sampling by the TIADC, applying bit shifters or multipliers after sampling to reduce the magnitudes of the signal samples, and lossy encoding. | 08-13-2009 |
| 20090254292 | FREQUENCY RESOLUTION USING COMPRESSION - 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. | 10-08-2009 |
| 20090290632 | COMPRESSION OF SIGNALS IN BASE TRANSCEIVER SYSTEMS - 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. | 11-26-2009 |
| 20100061505 | EDGE DETECTION FOR COMPUTED TOMOGRAPHY PROJECTION DATA COMPRESSION - A compression subsystem for a computed tomography system compresses projection data to for efficient data transfer and storage. The compression includes detecting edges in the projection data corresponding to the object being imaged to set boundaries for compression operations. The edge detection compares difference samples to positive and negative thresholds to determine the boundaries. The projection samples or the difference samples are compressed between the boundaries. The boundaries are encoded and included in the compressed data. The compressed samples are decompressed prior to image reconstruction processing. Decompression includes decoding the compressed samples and the boundary values. This abstract does not limit the scope of the invention as described in the claims. | 03-11-2010 |
| 20100070836 | ADAPTIVE COMPRESSION OF COMPUTED TOMOGRAPHY PROJECTION DATA - A compression subsystem for a computed tomography system compresses projection data to for efficient data transfer and storage. The compression includes applying an attenuation profile to an array of projection data samples. The attenuation profile is a function of sample coordinates and determines attenuation values applied to the samples. The attenuated samples are encoded and packed for data transfer. Alternatively, difference operators are applied to the attenuated samples and the differences are encoded. The average number of bits per compressed sample is monitored and the attenuation profiles can be modified to achieve a desired number of bits per compressed sample. The compressed samples are decompressed prior to image reconstruction processing. Decompression includes decoding the compressed samples and applying a gain profile to the decoded samples to restore the original dynamic range. This abstract does not limit the scope of the invention as described in the claims. | 03-18-2010 |
| 20100128949 | COMPRESSION AND STORAGE OF PROJECTION DATA IN A COMPUTED TOMOGRAPHY SYSTEM - A computed tomography system has a stationary part, a rotatable part mounted for rotation around an object to be examined and an interface between the stationary part and the rotatable part. The rotatable part includes an x-ray source, a sensor array for detecting x-rays passing through the object to produce projection data samples, a compressor that compresses the projection data samples and a storage device that stores the compressed samples. The storage device on the rotatable part can include one or more solid state drives. For image reconstruction, the compressed samples are retrieved from the storage device, transferred across the interface to the stationary part. A decompressor at the stationary part decompresses the received compressed samples and provides decompressed samples to the image reconstruction processor. This abstract does not limit the scope of the invention as described in the claims. | 05-27-2010 |
| 20100128998 | COMPRESSION AND STORAGE OF PROJECTION DATA IN A ROTATABLE PART OF A COMPUTED TOMOGRAPHY SYSTEM - A method and apparatus compress projection data and store the compressed projection data in a rotatable part that is mounted for rotation within a stationary part. The data acquisition source, compressor and storage device are connected to the rotatable part. The compressor compresses projection data samples provided by the data acquisition source to form compressed packets. The compressed packets are stored in the storage device, for example one or more solid state drives mounted on the rotatable part. A data access array contains information related to the location of the stored compressed packets. Compressed packets are retrieved and transferred across the interface to the stationary part. A decompressor at the stationary part decompresses the received compressed packets to form decompressed samples of the corresponding projection data. This abstract does not limit the scope of the invention as described in the claims. | 05-27-2010 |
| 20100305449 | ULTRASOUND SIGNAL COMPRESSION - A method and an apparatus for an ultrasound system provide compression of ultrasound signal samples after analog to digital conversion and before beamforming. The analog ultrasound signals received from an array of ultrasound transducer elements are digitally sampled by a plurality of analog to digital converters (ADCs) to produce a plurality of sequences of signal samples. Each sequence of signal samples is compressed to form a corresponding sequence of compressed samples. The resulting sequences of compressed samples are transferred via a digital interface to an ultrasound signal processor. At the ultrasound signal processor, the received sequences of compressed samples are decompressed. The typical processing operations, such as beamforming, downconversion and detection, are applied to decompressed samples. This abstract does not limit the scope of the invention as described in the claims. | 12-02-2010 |
| 20100331689 | POST-BEAMFORMING COMPRESSION IN ULTRASOUND SYSTEMS - In an ultrasound imaging system that applies a beamformer to received ultrasound signal samples to form one or more beams represented by arrays of beamformed samples, a method and an apparatus compress each array of beamformed samples independently of the other arrays to form compressed beams. A plurality of analog to digital converters sample multiple analog ultrasound signals produced by a transducer array to provide multiple streams of ultrasound signal samples to the beamformer. The compressed beams are transferred via a digital interface to a signal processor. At the signal processor, the compressed beams are decompressed to form decompressed beams. The signal processor further processes the decompressed beams for diagnostic imaging, such as for B-mode and Doppler imaging, and scan conversion to prepare the resulting ultrasound image for display. This abstract does not limit the scope of the invention as described in the claims. | 12-30-2010 |
| 20110078222 | ENHANCED MULTI-PROCESSOR WAVEFORM DATA EXCHANGE USING COMPRESSION AND DECOMPRESSION - Configurable compression and decompression of waveform data in a multi-core processing environment improves the efficiency of data transfer between cores and conserves data storage resources. In waveform data processing systems, input, intermediate, and output waveform data are often exchanged between cores and between cores and off-chip memory. At each core, a single configurable compressor and a single configurable decompressor can be configured to compress and to decompress integer or floating-point waveform data. At the memory controller, a configurable compressor compresses integer or floating-point waveform data for transfer to off-chip memory in compressed packets and a configurable decompressor decompresses compressed packets received from the off-chip memory. Compression reduces the memory or storage required to retain waveform data in a semiconductor or magnetic memory. Compression reduces both the latency and the bandwidth required to exchange waveform data. This abstract does not limit the scope of the invention as described in the claims. | 03-31-2011 |
| 20110099295 | BLOCK FLOATING POINT COMPRESSION OF SIGNAL DATA - A method and apparatus for compressing signal samples uses block floating point representations where the number of bits per mantissa is determined by the maximum magnitude sample in the group. The compressor defines groups of signal samples having a fixed number of samples per group. The maximum magnitude sample in the group determines an exponent value corresponding to the number of bits for representing the maximum sample value. The exponent values are encoded to form exponent tokens. Exponent differences between consecutive exponent values may be encoded individually or jointly. The samples in the group are mapped to corresponding mantissas, each mantissa having a number of bits based on the exponent value. Removing LSBs depending on the exponent value produces mantissas having fewer bits. Feedback control monitors the compressed bit rate and/or a quality metric. This abstract does not limit the scope of the invention as described in the claims. | 04-28-2011 |
| 20110135013 | COMPRESSION OF BASEBAND SIGNALS IN BASE TRANSCEIVER SYSTEMS - 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 baseband signal samples resulting from analog to digital conversion of a received analog signal followed by digital downconversion. The compressed signal samples are transferred over the serial data link to the baseband processor then decompressed prior to normal signal processing. For the downlink, the baseband processor compresses baseband signal samples and transfers the compressed signal samples to the RF unit. The RF unit decompresses the compressed samples prior to digital upconversion and digital to analog conversion to form an analog signal for transmission over an antenna. Compression and decompression can be incorporated into operations of conventional base stations and distributed antenna systems, including OBSAI or CPRI compliant systems. | 06-09-2011 |
