Abstract: A video signal encoding apparatus comprises a decoding unit for decoding each compression still image data into a frame image; a supplementary information, extracting unit for extracting supplementary information added to each compression frame image data; a motion prediction process adoption judging unit for judging, on the basis of the supplementary information, whether the frame image can be subjected to a motion prediction process; and a compression moving image generating unit for selecting the inter-frame prediction encoding method and the intra frame encoding method on the basis of a judgement result by the motion prediction process adoption judging unit to generate the moving image data.

Abstract: A method of generating a reference signal includes acquiring a base sequence and acquiring a reference signal sequence with a length N from the base sequence. Good PAPR/CM characteristics of the reference signal can be kept to enhance performance of data demodulation or uplink scheduling.

Abstract: In an apparatus and method for providing transmit (Tx) diversity in a multi-antenna wireless communication system, Tx diversity is provided by estimating a channel to each antenna using a signal received from the antenna, estimating channel state information (CSI) from the first Tx node to each antenna using the estimated channel, and determining a signal to be transmitted to the antennas in different methods according to whether phase compensation is required for information to be transmitted using the estimated channel and the CSI.

Abstract: Various embodiments are disclosed relating to a wireless transceiver. In an example embodiment, a method of compensating for phase imbalance and amplitude imbalance between corresponding in-phase signals and quadrature-phase signals includes providing a plurality of test tones of various frequencies to a receiver and determining, for each of the test tones, a respective phase imbalance and a respective amplitude imbalance between an in-phase (I) signal and a quadrature-phase (Q) signal of the test tone. The example method also includes determining a set of filter coefficients based on the determined phase and amplitude imbalances of the plurality of test tones and applying the set of filter coefficients to a plurality of filters. In the example method, a phase imbalance between an I signal and a Q signal of a received wireless signal is compensated for using a first filter of the plurality of filters.

Abstract: Embodiments for non-coherent phase differential and multiple orthogonal signal modulation/demodulation are disclosed. One illustrative embodiment may include: a method for non-coherent reception of a signal with spectrum spreading, comprising performing a multiple orthogonal signal demodulation operation on the signal; performing a phase differential demodulation operation on the signal; and combining the results of the multiple orthogonal signal demodulation operation on the signal and the phase differential demodulation operation on the signal.

Abstract: Systems and methods for packet detection for frequency hopping networks. Multiple receiver chains are set to different frequencies to check for packets at the different frequencies, at least until receipt of a preamble sequence in a packet is received. After detection of a packet at least some of the receiver chains are used to process received signals according to a frequency hopping pattern.

Abstract: A demodulator system and method is disclosed. In an embodiment, the demodulator system can include a Coordinate Rotation Digital Computer (CORDIC) mixer to mix a first signal substantially to baseband using a first input frequency and to mix a second signal substantially to baseband using a second input frequency. In another embodiment, the demodulator system can include a phase detector to receive a pilot signal and to generate a control signal to adjust a decimation rate based on the pilot signal. In another embodiment, the demodulator system can include a symbol decoder to determine a symbol from a phase signal.

Abstract: Disclosed is a method and an apparatus for self-calibrating direct current (DC) offset and imbalance between orthogonal signals, which may occur in a mobile transceiver. In the apparatus, a transmitter of a mobile terminal functions as a signal generator, and a receiver of the mobile terminal functions as a response characteristic detector. Further, a baseband processor applies test signals to the transmitter, receives the test signals returning from the receiver, and compensates the imbalance and DC offset for the transmitter side and the receiver side by using the test signals.

Abstract: A wireless communication device includes an antenna configured to receive electromagnetic energy corresponding to a wireless communication signal outputted using an interrogator and to output electrical energy corresponding to the received electromagnetic energy, communication circuitry coupled with the antenna and configured to sample the electrical energy to process the wireless communication signal, synchronization circuitry coupled with the antenna and the communication circuitry and configured to generate a clock signal to control sampling of the electrical energy using the communication circuitry, wherein the synchronization circuitry is configured to generate a plurality of transitions within the clock signal responsive to a plurality of transitions of the electrical energy during a first data period and wherein the synchronization circuitry is configured to generate a plurality of transitions within the clock signal during a second data period including generating at least one of the transitions indep

Abstract: Disclosed is a clock and data recover circuit including N flip-flops (F/Fs) for sampling an input data signal using N-phase clocks, a phase comparison circuit for performing phase comparison based on outputs of the F/Fs, a filter or smoothing a result of the phase comparison and outputting an up/down signal, up/down counters, each for receiving an output of the filter and counting up or down a count value thereof, a phase shift circuit for adjustably controlling phases of the clocks for edge detection and the clocks for data sampling according to phase control signals from an up/down counter and an up/down counter, respectively, and an up/down control circuit for receiving a control signal for controlling maximum and minimum values of count values of the up/down counter, generating a signal for controlling counting up and down of the up/down counter based on the count value of the up/down counter, and supplying the generated signal to the up/down counter.

Abstract: Provided are a synchronization apparatus and method for improving timing estimation performance in an OFDM-FDMA/CDMA/TDMA system, which can correctly estimate symbol timing through a more correct timing metric using a guard interval of a preamble. The synchronization apparatus includes an auto-correlator for calculating an auto-correlation value of a received signal and a signal delayed by a predetermined time, a power detector for calculating power of the received signal, a timing metric/normalizer for normalizing the auto-correlation value by dividing the auto-correlation value by the calculated power to obtain a timing metric, and a peak detector for finding a peak value of the timing metric to estimate a frame starting position and an initial symbol timing. The auto-correlator calculates an auto-correlation length as long as a length of a guard interval, considering the preamble characteristic that the patterns are repeated in the time domain.

Abstract: Disclosed is a signal detection method for a receiver of a Multiple-Input Multiple-Output (MIMO) communication system having nT and nR (where nR is greater than or equal to nT) transmission and reception antennas, respectively, and an nT×nR channel matrix. The signal detection method includes selecting a plurality of sub-channel matrices having smaller dimensions than the nT×nR channel matrix, estimating transmission symbols received from corresponding transmission antennas using a maximum likelihood decoding method with respect to a received signal corresponding to each of the sub-channel matrices, estimating transmission symbols received from the remaining transmission antenna(s) using the estimated transmission symbols, temporarily storing a candidate symbol set composed of the estimated transmission symbols, and comparing candidate symbol sets corresponding to all the sub-channel matrices and determining the smallest candidate symbol set as a transmission symbol set.

Abstract: A compact transmission circuit for outputting a highly linear transmission signal regardless of the output power level and operating at a high efficiency is provided. A signal generation section 11 generates an amplitude signal and quadrature data based on input data. A calculation section 21 calculates using the amplitude signal and the quadrature data to output a discrete value having a level discrete at every predetermine time period, and first and second phase signals. An amplitude amplification section 17 outputs a voltage controlled in accordance with the discrete value. Angular modulation sections 13 and 14 angular-modulate the phase signals and output first and second angle-modulated signals. Amplitude modulation sections 15 and 16 amplitude-modulate the angle-modulated signals with the voltage from the amplitude amplification section 17 and output first and second modulated signals. A combining section 18 combines the first and second modulated signals and outputs a transmission signal.

Abstract: A wireless communication apparatus which uses fast Fourier transforms (FFTs) in an orthogonal frequency division multiplexing (OFDM) receiver which incorporates a beam space antenna array. The beam space antenna array may be implemented with a Butler matrix array. The beam space antenna array may be a circular array, vertical array, or a combination of both circular and vertical arrays, for providing the desired angular antenna coverage. In one embodiment, the antenna array is optimized because the FFTs are linear invariant transform operators, whereby the order of operations in the OFDM receiver can be interchanged.

Abstract: A system and method for crest factor reduction of OFDM transmission systems using selective sub-carrier degradation, is disclosed. A modulated communications signal comprising a series of symbols is converted into parallel format in groups of plural symbols in the frequency domain. Crest factor reduction reduces a primary peak of the groups of plural symbols by selective sub-carrier degradation, to generate peak reduction symbols. The groups of plural symbols are converted into time domain symbols, and combined with the peak reduction symbols to provide peak reduced symbols in time domain.

Abstract: An RF transmitter (10) includes a linear predistorter (22) and a nonlinear predistorter (24) which together drive analog transmitter components (14). The linear and nonlinear predistorters (22, 24) are implemented using a collection of adaptive equalizers (30). A feedback signal (20) is developed by downconverting an RF communication signal (16) obtained from the analog components (14). The feedback signal (20) are used in driving tap coefficients (34) for the adaptive equalizers (30?, 30?) in the nonlinear predistorter (24). An intermodulation-product canceller (94) uses signal cancellation to cancel intermodulation products from the feedback signal (20) and generate an intermodulation-neutralized feedback signal (96). The intermodulation-neutralized feedback signal (96) is used along with a modulated convergence factor (43) in driving tap coefficients (34) for the adaptive equalizer (30) in the linear predistorter (22).

Abstract: An update algorithm for equalizer coefficients in a communications system using phase correction symbols. Instead of using a traditional all symbols slicer update algorithm, the equalizer is updated during phase correction symbols for optimal performance in low signal-to-noise ratio conditions. In lower signal-to-noise ratio conditions, the equalizer uses a phase correction circuit to compensate for distortion caused by a communication channel when a demodulated data stream contains an unknown phase offsets resulting from a fast dynamic distortion. More specifically, the phase correction circuit uses a phase correction signal to correct for the unknown phase offsets in a demodulated data stream in lower signal-to-noise ratio conditions. The equalizer then corrects for distortion caused by the communication channel based upon the phase corrected demodulated data stream.

Abstract: A physical layer device (PLD) includes a first serializer-deserializer (SERDES) device and a second SERDES device. Each SERDES device includes an analog portion with a serial port that is configured to communicate serial data with various network devices, and a digital portion that is configured to communicate parallel data with other various network devices. The PLD includes a first signal path that is configured to route serial data signals between the analog portions of the SERDES devices, bypassing the digital portions of the SERDES devices. Therefore, the SERDES devices can directly communicate serial data without performing parallel data conversion. A second signal path is configured to route recovered clock and data signals between the analog portions of the SERDES devices, but still bypassing the digital portions of the SERDES devices. The recovered clock and data signals are then regenerated before being transmitted over a network device.

Abstract: The method and apparatus in accordance with the present invention receives bits, writes the bits row-by-row in a matrix, reads the bits column-by-column from the matrix, groups and rotates the bits read column-by-column from the matrix so as to evenly separate the bits in position, frequency, space over one symbol period.

Abstract: A radio transmitter includes an orthogonal transformation unit for carrying out an orthogonal transformation on pilot signals having orthogonal relation to each other between transmission antennas and a pilot multiplexing unit multiplexing the pilot signals and transmission data, and a radio receiver includes a channel estimation unit obtaining a channel estimate of a directive multibeam for each of reception antennas, an inverse transformation unit carrying out an inverse transformation of the orthogonal transformation on the obtained channel estimate and a received signal processing unit selectively conducting first processing based on the beam channel estimate in the first mode or second processing based on the channel estimate obtained by the inverse transformation unit in the second mode. This commonizes a common pilot for MIMO (second mode) and individual pilots for AAA (first mode), thus realizing the coexistence of MIMO and AAA without leading to a reduction of throughput.