Abstract: By inserting a symbol start tag at a start of a data segment corresponding to each symbol of a multimedia data stream, and by inserting frame start tags at starts of different frames in a start data segment, data signals belonging to different channels can be precisely and rapidly classified and decoded when the multimedia data stream is performed with demodulation.

Abstract: A channel scanning method for Digital Video Broadcasting—Satellite (DVB-S) signals is provided. The method includes: scanning a radio frequency (RF) signal according to a normal frequency step; when the Nth channel is detected, obtaining a difference between a low boundary of an Nth channel and a high boundary of an (N?1)th channel; and, when the difference is within a predetermined bandwidth range, scanning the RF signal between the high boundary of the (N?1)th channel and the low boundary of the Nth channel according to a narrow frequency step. The normal frequency step is greater than the narrow frequency step.

Abstract: An error correction apparatus for a digital signal received by a signal reception terminal includes two error correction modules. The first error correction module performs first error correction on an input signal to generate an intermediate signal satisfying a termination condition. The second error correction module receives and selectively performs second error correction on the intermediate signal to generate a corrected signal. The termination condition is associated with a maximum error correction capability of the second error correction.

Abstract: A packet processing method applied in a packet receiver is provided. An approximate bit rate is first determined according to time stamps of two different packets. The approximate bit rate is corrected according to a time stamp of another packet to generate a fine-tuned bit rate. According to the fine-tuned bit rate, one or more subsequent packets are read out from a buffer. The time stamp of a subsequent packet is provided according to the approximate bit rate.

Abstract: A readdressing decoder for QC-LDPC decoding including a memory, a controller and parallel processors is provided. The memory stores a QC-LDPC matrix including sub-matrices respectively addressed with a corresponding address. The controller readdresses each of the sub-matrices into divided matrices and defines each of the divided matrices into a first address group and a second address group. The controller further respectively transmits the divided matrices of the first address group and the second address group to the parallel processors to perform correction algorithm.

Abstract: An apparatus for detecting spectrum inversion includes a different correlator and a determining module. The differential correlator performs an odd-order differential correlation on an input signal and a known signal to generate a differential correlation result. When the input signal is determined as corresponding to a target signal of the known signal, the determining module detects spectrum inversion in the input signal according to the phase of the differential correlation result.

Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises shifting a characteristic of the first signal with respect to a like characteristic of the second signal to mitigate co-channel interference, and transmitting the first signal and the second signal over different channels of the communication system.

Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises scrambling a first frame using a first scrambling code, attaching a first header to the first frame to create the first signal, scrambling a second frame using a second scrambling code, attaching a second header to the second frame to create the second signal, and transmitting the first signal and the second signal over different channels of the communication system.

Abstract: An apparatus for correcting a phase error is provided. The apparatus includes an error estimating module and a correcting module. The error estimating module receives a phase-shift keying signal, and calculates a phase error according to the phase-shift keying signal, a plurality of known candidate signals and Bayesian estimation. The correcting module corrects the phase-shift keying signal according to the phase error.

Abstract: A signal processing apparatus includes an initial detecting module, a mixer, a symbol rate detecting module, a judging module and a correcting module. The initial detecting module determines an initial carrier frequency offset of an input signal according to a spectrum of the input signal. The mixer adjusts the input signal according to the initial carrier frequency offset to generate a frequency-compensated signal. The symbol rate detecting module determines a symbol rate of the input signal. The judging module judges whether the initial carrier frequency offset is correct according to the frequency-compensated signal. When a judgment result of the judging module is negative, the correcting module determines a corrected carrier frequency offset according to the symbol rate and the spectrum.

Abstract: A signal processing apparatus for receiving a spectral line of an original signal includes a starting point determining module, a searching module and a symbol rate determining module. The starting point determining module finds a maximum energy in the spectral line and determines at least one search starting point according to the maximum energy. From the at least one search starting point, the searching module searches along the spectral line towards a region with a lower energy for at least one minimum energy satisfying a predetermined condition. The symbol rate determining module determines a symbol rate of the original signal according to the at least one minimum energy.

Abstract: A symbol rate detection apparatus includes an analog-to-digital converter (ADC), a coarse detection module, a mixer, a down-sampling module, and a fine detection module. The ADC converts an analog input signal to a digital input signal at an original sampling frequency. The coarse detection module estimates a carrier frequency offset and a coarse symbol rate according to the digital input signal. The mixer adjusts the frequency of the digital input signal according to the carrier frequency offset to generate a frequency-compensated signal. The fine detection module determines a fine symbol rate according to the frequency-compensated signal.

Abstract: A decoding method for determining a preferred survivor path in a decoding process is provided. The method includes calculating a first determination value of a first survivor path at a first time point, the first determination value being determined by a first sub determination value and a second determination value at a second time point, and the second time point being prior to the first time point; calculating a third determination value of a second survivor path at the first time point, the third determination value being determined by a second sub determination value and a fourth determination value at the second time point; and when a difference between the first determination value and the third determination value is equal to or less than a predetermined value, determining the preferred survivor path at the first time point according to the second and the fourth determination values, or the first and the second sub determination values.

Abstract: A packet processing method applied in a packet receiver is provided. An approximate bit rate is first determined according to time stamps of two different packets. The approximate bit rate is corrected according to a time stamp of another packet to generate a fine-tuned bit rate. According to the fine-tuned bit rate, one or more subsequent packets are read out from a buffer. The time stamp of a subsequent packet is provided according to the approximate bit rate.

Abstract: A readdressing decoder for QC-LDPC decoding including a memory, a controller and parallel processors is provided. The memory stores a QC-LDPC matrix including sub-matrices respectively addressed with a corresponding address. The controller readdresses each of the sub-matrices into divided matrices and defines each of the divided matrices into a first address group and a second address group. The controller further respectively transmits the divided matrices of the first address group and the second address group to the parallel processors to perform correction algorithm.

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: Methods and apparatuses for determining scrambling codes for minimizing co-channel interference in a communication system. A method in accordance with the present invention comprises defining at least one initial default sequence, generating a scrambling code, scrambling a signal using the generated scrambling code, comparing the scrambled signal with all other scrambled signals meeting a specified criterion, and saving the scrambling code word if the comparison determines that the signal scrambled with the scrambling code also meets the specified criterion. The scrambling codes can be compared with each other for cross-correlation purposes to determine whether they meet the specified criterion based on laboratory testing.

Abstract: A decoding method for determining a preferred survivor path in a decoding process is provided. The method includes calculating a first determination value of a first survivor path at a first time point, the first determination value being determined by a first sub determination value and a second determination value at a second time point, and the second time point being prior to the first time point; calculating a third determination value of a second survivor path at the first time point, the third determination value being determined by a second sub determination value and a fourth determination value at the second time point; and when a difference between the first determination value and the third determination value is equal to or less than a predetermined value, determining the preferred survivor path at the first time point according to the second and the fourth determination values, or the first and the second sub determination values.

Abstract: Systems and methods for characterizing amplifiers. A system for characterizing an amplifier in accordance with the present invention comprises a Gaussian signal source for generating a signal in the frequency domain, a notch filter, coupled to the Gaussian Noise source, wherein the notch filter has a notch at a specified frequency and a frequency bandwidth, the frequency bandwidth encompassing the specified frequency, an Inverse Fast Fourier Transform device, coupled to an output of the notch filter, a normalization device, coupled to the Inverse Fast Fourier Transform device, an amplifier under test, coupled to the normalization device, for amplifying the signal generated by the Gaussian signal source, and a measurement device, coupled to an output of the amplifier, for measuring a power output of the amplifier in the frequency bandwidth and a noise output at the specified notch frequency, and for calculating the ratio between the power output and the noise output.

Abstract: Systems for delivering a plurality of broadcast programs where the transmitter and receiver roll-off factors are mismatched. A system in accordance with the present invention comprises a transmitter comprising a modulator, and a plurality of receivers, each receiver in the plurality of receivers receiving the plurality of broadcast programs, each receiver in the plurality of receivers further comprising a demodulator; wherein the modulator has a first root-raised cosine filter having a first roll-off factor and each receiver has a second root-raised cosine filter having a second roll-off factor, the first roll-off factor being smaller than the second roll-off factor.