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 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. The present invention improves A/D converters by compressing the sampled version of the 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, the present invention improves D/A converters by decreasing the required bit rate of the D/A converter's digital interface. D/A converters enhanced by the present invention include a decompressor that decompresses the D/A converter's compressed digital input in real time, prior to conversion to an analog output signal. The present invention's simplicity and its ability to be implemented using multiple compression and decompression elements allow its use in A/D and D/A converters with arbitrarily high sampling rates.

Abstract: An enhancement that improves the performance of test and measurement equipment such as digital oscilloscopes and arbitrary waveform generators through the use of compression and decompression is described. The present invention is particularly effective for compressing and decompressing high-speed, bandlimited analog signals that are not appropriately or cannot effectively be compressed by prior art speech, audio, image, and video compression algorithms due to various limitations of such prior art compression solutions. The present invention improves digital oscilloscopes by compressing the sampled version of an analog waveform under observation in real time, allowing a significantly longer duration of the waveform to be stored in the oscilloscope's capture memory, when compared with the duration of the same signal's uncompressed waveform stored in the same memory.

Abstract: An efficient method for compressing sampled analog signals in real time, without loss, or at a user-specified rate or distortion level, is described. The present invention is particularly effective for compressing and decompressing high-speed, bandlimited analog signals that are not appropriately or effectively compressed by prior art speech, audio, image, and video compression algorithms due to various limitations of such prior art compression solutions. The present invention's preprocessor apparatus measures one or more signal parameters and, under program control, appropriately modifies the preprocessor input signal to create one or more preprocessor output signals that are more effectively compressed by a follow-on compressor. In many instances, the follow-on compressor operates most effectively when its input signal is at baseband. The compressor creates a stream of compressed data tokens and compression control parameters that represent the original sampled input signal using fewer bits.