239 results about "Differential coding" patented technology

An audio fingerprint is extracted from an audio sample, where the fingerprint contains information that is characteristic of the content in the sample. The fingerprint may be generated by computing an energy spectrum for the audio sample, resampling the energy spectrum logarithmically in the time dimension, transforming the resampled energy spectrum to produce a series of feature vectors, and computing the fingerprint using differential coding of the feature vectors. The generated fingerprint can be compared to a set of reference fingerprints in a database to identify the original audio content.

A method for compressing audio input signals to form a master bit stream that can be scaled to form a scaled bit stream having an arbitrarily prescribed data rate. A hierarchical filterbank decomposes the input signal into a multi-resolution time/frequency representation from which the encoder can efficiently extract both tonal and residual components. The components are ranked and then quantized with reference to the same masking function or different psychoacoustic criteria. The selected tonal components are suitably encoded using differential coding extended to multichannel audio. The time-sample and scale factor components that make up the residual components are encoded using joint channel coding (JCC) extended to multichannel audio. A decoder uses an inverse hierarchical filterbank to reconstruct the audio signals from the tonal and residual components in the scaled bit stream.

In an embodiment, bitstream elements of sub-frames are encoded differentially to a global gain value so that a change of the global gain value results in an adjustment of an output level of the decoded representation of the audio content. Concurrently, the differential coding saves bits. Even further, the differential coding enables the lowering of the burden of globally adjusting the gain of an encoded bitstream. In another embodiment, a global gain control across CELP coded frames and transform coded frames is achieved by co-controlling the gain of the codebook excitation of the CELP codec, along with a level of the transform or inverse transform of the transform coded frames. In another embodiment, the gain value determination in CELP coding is performed in the weighted domain of the excitation signal.

A large-capacity CDMA transmission system that can realize communication with a moving unit such as an automobile, transmitting more quantity of information than the conventional system without increasing the occupied band width, using the same or narrower frequency band width.

This system assumes the code division multiple access (CDMA) transmission system for simultaneous multiple communication, which performs phase modulation on a carrier signal while maintaining a phase of the carrier signal in a predetermined period at a predetermined value, so as to generate a primary modulated wave, and then, multiplies the obtained primary modulated wave by a spread code sequence. On the transmitting side, a differential coding phase modulation (DPSK) is employed to generate a primary modulated wave. On the other hand, on the receiving side, a quasi-synchronous detection and difference operation are utilized to detect the phase difference between the last symbol interval and the current symbol interval, and the detected phase difference is given as the information of the current symbol interval.

In a spread spectrum system, methods and despreader architectures for despreading the received spreaded codes with the use of a single correlator and a single correlation code is provided. Before despreading the incoming received spreaded codes, a single correlation code is generated using a symbol from a set of symbols that has been mapped into a set of differential encoded PN codes. Despreading output samples for each received spreaded code are obtained by correlating the received spreaded code with this single correlation code. Correlation is accomplished by multiplying each received sample of the received spreaded codes with the correlation code samples and accumulating the products of this multiplication. After correlation, the index for the maximum or minimum peak of the despreading output samples for each code is identified. This index can then be mapped into a symbol corresponding to the transmitted information. Corresponding despreader architectures comprise of a number of taps attached to a series of shift registers. Received samples of each received spreaded codes are inputted into the shift registers. The despreader architectures accumulates the products of multiplication of the value of the shift register with a predetermined value associated with each tap to produce the despreading output samples of a received spreaded code. It identifies the despreading output index producing the maximum of the absolute value of the despreading output and maps said index into a symbol corresponding to the transmitted information.

A differential space-time block coder produces successive space-time blocks of symbols from M-PSK symbols to be encoded, in accordance with an orthogonal matrix and a normalization factor. Differentially encoded space-time output blocks, for transmission via a plurality of transmit antennas (16, 18) of a wireless communications system, are produced by multiplying (42) each space-time block from the space-time block coder (40) by the respective previous (44) differentially encoded space-time output block. Decoding is independent of channel estimation, and the arrangement is simple, avoids error propagation, and is applicable to different numbers of transmit antennas.

Optical data signal receiver having an optical separation of the received data signal into two signal paths, namely, an amplitude detection path and a phase detection path, wherein the phase detection path is split into an in-phase signal path generating in-phase-signals and a quadrature-signal path generating quadrature-signals, and both the in-phase-signal path and the quadrature-signal path, as well as the amplitude detection path, are connected to an analysis unit for demodulation of the received data signal, in which a normalizer and thereafter a symbol discriminator and a data reconstruction logic are arranged in the analysis unit. In the receiver, a connection is provided at least from the amplitude detection path to the normalizer, the normalizer normalizing the in-phase and quadrature-signals with the aid of the signal output from the amplitude detection path, the symbol discriminator discriminating the symbols output from the normalized in-phase and quadrature-signals. Additional connections can be provided from the amplitude detection path signal.

The present invention provides a serializer/deserializer (SERDES) circuit that can cover both client- and network-side interfaces for high-speed data rates. The present invention leverages commonality between the client and network (also known as line) side, and accommodates differences in a flexible manner. In one exemplary embodiment, the present invention provides a four-channel implementation to meet the requirement of both interfaces. The SERDES circuit can be capable of supporting both 40 Gb/s and 56 Gb/s data rates, can include an integrated DQPSK pre-coder and I/Q input/output signals, and can support RZ clock recovery. Additionally, the SERDES circuit can include differential coding support, electronic pre-emphasis, receiver-side electronic dispersion compensation, and the like.

The invention relates to a dual-mode real-time pseudo-range differential positioning system and a pseudo-range correction data generation method. The system comprises a central processor, a GNSS reference station, and a differential data transmitting link module, wherein the GNSS reference station and the differential data transmitting link module are connected with the central processor. The GNSS reference station comprises a BDS, a GPS dual-mode receiver, and a GNSS receiving antenna, wherein the coordinate precision of installation points is known. The central processor comprises a GNSS navigation data resolving module, a differential data generation module, and an RTCM differential data coding module. The differential data transmitting link module comprises an MSK modulation module, a transmitter, and a transmitting antenna, wherein the MSK modulation module, the transmitter and the transmitting antenna are connected sequentially. The method comprises the steps: enabling the GNSS reference station to receive the ephemeris and navigation data, obtained through observation at the same moment, of all GPS and BDS satellites, and transmitting the data to the central processor in real time; extracting data of all satellites; calculating the distances from the station to the satellites; obtaining a pseudo-range correction value and a pseudo-range correction value change rate; and transmitting the data to a peripheral GNSS user after RTCM differential coding and MSK modulation. The system and method greatly improve the real-time navigation positioning precision.

The present invention relates generally to an optical CDMA transmission system and method employing differential optical encoding and bipolar decoding. Differential encoding and bipolar decoding may be performed at the bit level, wherein differential phase encoding and decoding occurs on an entire composite signal. Differential encoding and bipolar decoding may also be performed at the chip level, wherein differential phase encoding and decoding occurs on individual spectral components of a given signal.

The invention provides an optical communication method which comprises the steps of: modulating obtained bit stream data to obtain a modulating signal; carrying out differential coding on the modulating signal to obtain a differential coding signal; converting the differential coding signal into an electrical signal; mapping the electrical signal on an optical carrier to form an optical signal; and then transmitting the optical signal. By using the method, on the premise that a frequency spectrum utilization rate is not reduced, the system capability of resisting disturbance among carriers is enhanced; thus, the tolerance of the existing optical communication sysem for resisting laser linewidth, quick change PMD (Physical Media Dependent), nonlinear fiber, disturbance among channels and other damage is enhanced; and system performance is greatly enhanced.

A differential STBC transmitting/receiving apparatus in a multiple antenna system using eight or less transmit antennas is provided. In the differential STBC transmitting apparatus, a symbol mapper receives binary data and generates a number of symbols from the binary data, each symbol having a number of bits. A space-time block encoder generates an STBC by encoding the symbols. A differential processor differentially encodes the STBC through feedback and delay. A distribution matrix processor substitutes the differentially coded STBC into a distribution matrix preset according to the number of transmit antennas, and outputs the differential STBC code of the distribution matrix to the transmit antennas.

The invention relates to tumor-related IncRNA and tumor-related IncRNA function predication. By taking differential expression of IncRNA in tumors as diagnosis references, a process for finding a relation between IncRNA and tumors includes: step one, downloading data from GEO database, processing the data to obtain expression data of part of IncRNA and exons; step two, subjecting the processed expression data to differential expression analysis; step three, analyzing co-expression and differential coding genes and IncRNA for IncRNA in differential expression; step four, subjecting the coding genes to probe platform annotation; step five, further screening the IncRNA in differential expression to select out most obviously differential IncRNA; step six, performing enrichment analysis to obtain a GOBP process and pathyway, and speculating IncRNA functions through coding gene related biological processes; step seven, analyzing whether common coding genes obtained at the step six can enter blood, saliva and urine or not, analyzing genes which are allowed to enter, and taking the genes and IncRNA as potential predication marks of cancers.

A method of provided for transmitting and receiving OFDM data signals via multiple outputs of a channel including multiple sub-channels. Transmit data streams are modulated by de-multiplexing the data streams into multiple parallel frequency-domain sub-channel data for conversion into time-domain data; and frequency-domain data for each sub-channel is converted into time-domain data. For each sub-channel, the corresponding time-domain data is differentially encoded to obtain differentially encoded time-domain data; and transmitting the differentially encoded time-domain data. The received signals are converted into digital data signals, and for each sub-channel, corresponding time-domain data from the data signals is differentially decoded to obtain differentially decoded time-domain data. The time-domain data for each sub-channel is converted into frequency-domain data and the frequency-domain data is demodulated into data streams by de-multiplexing the data streams into multiple parallel frequency-domain sub-channel data.

Methods and systems for processing an optical signal in a communication system are disclosed. The disclosed methods yield benefits for estimation and tracking of carrier phase of received signals at a digital coherent receiver without the use of differential coding. Specifically, phase ambiguity is removed by calculating the slope of the CPE at a location where the CPE begins to lose track of the received carrier phase signal. As such, a CPE offset adjustment may be applied in accordance with the calculated slope to reduce the number of ones and zeros corrected by a FEC decoder. Thus, the FEC aided CPE scheme may be a feed forward scheme that requires no training.

The invention provides a system for a differential space time transmit diversity in a multicarrier modulation system and an implement method thereof, wherein the implement method comprises the following steps: A, a modulation signal is subjected to differential coding by a differential space time coder and is output to two paths; and B, one path of signal in the step A passes through an OFDM modulator and a cyclic prefix insertion device and is transmitted by an antenna, the other path of coding signal passes through another OFDM modulator and is transmitted to a time delay delta unit, after the signal is subjected to cyclic time delay with delta delayed time, the signal is transmitted to the cyclic prefix insertion device, inserted with cyclic prefix and transmitted by an antenna. On the premise of ensuring the transmission speed, the system can obtain high space time diversity gain and effectively improve system performance.

A plurality of differential encoders encodes a plurality of parallel data bit streams. XOR gates interleave the outputs of the differential encoders forming a single high speed differentially encoded bit stream with a data rate unachievable using only a differential encoder. The high speed data stream provides a single differentially encoded input to a differential phase shift keying modulator that generates symbols for a high speed optical communication system.