Abstract: An apparatus, logic, and method of performing timing and frequency estimation in a MediaFLO™ mobile multimedia multicast system comprising a receiver and a transmitter, wherein the method comprises receiving a wireless data stream comprising a MediaFLO™ mobile multimedia multicast system superframe comprising Orthogonal Frequency Division Multiplexing (OFDM) symbols; estimating a Fast Fourier Transform (FFT) trigger point for each of the received OFDM symbols; estimating a fine carrier frequency offset of each OFDM symbol; determining the start of the MediaFLO™ mobile multimedia multicast system superframe by locating a Time Division Multiplexed (TDM) pilot symbol in the superframe; estimating a coarse carrier frequency offset of each of the received OFDM symbols; and synchronizing the receiver to the start of the MediaFLO™ mobile multimedia multicast system superframe and the transmitted OFDM symbols based on the fine carrier frequency offset, the TDM pilot symbol, and the coarse carrier frequency offset.

Abstract: A technique for re-acquiring a symbol index in the presence of sleep timer errors in a MediaFLO™ (Forward Link Only) mobile multimedia multicast system comprising a receiver and a transmitter, wherein the method comprises receiving a digital signal comprising a superframe comprising one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols in the receiver comprising a timer; waking up the receiver from a sleep mode of operation by an amount of time equal to a maximum error introduced by the timer plus a time to reacquire a beginning of each OFDM symbol plus a time to reacquire a symbol index; and reacquiring the symbol index.

Abstract: A technique for estimating a carrier frequency offset and a timing offset in a MediaFLO™ (Forward Link Only) system, wherein the method comprises receiving Orthogonal Frequency Division Multiplexing (OFDM) symbols; interpolating pilots on odd or even symbols of the received OFDM symbols; determining a phase difference between two successive symbols using the interpolated pilots; obtaining an estimate of the carrier frequency offset and the timing offset from the determined phase difference between two successive symbols; and correcting a sampling frequency in accordance with the estimated carrier frequency offset and timing offset.

Abstract: An apparatus, method, and system for reducing a C/N in an OFDM receiver using diversity combining techniques in the presence of ICI, wherein the apparatus comprises an encoded data estimator adapted to estimate data received in the OFDM receiver; a pair of ICI estimators operatively connected to the encoded data estimator and adapted to calculate an inter-carrier-interference term of the data; and a pair of diversity combining equalizers adapted to compensate multi-path interference of the data, wherein a first one of the diversity combining equalizers is operatively connected to the encoded data estimator, and a second one of the diversity combining equalizers is operatively connected to the pair of ICI estimators. The diversity combining equalizer may comprise a MRC diversity combining equalizer. Preferably, the encoded data estimator, the pair of ICI estimators, and the pair of diversity combining equalizers are implemented on a DVB-T/H diversity SoC.

Abstract: A technique for estimating maximum Doppler frequency of a wireless signal in a wireless communication system, wherein the method comprises receiving a wireless signal; determining an impulse response of the received wireless signal; determining an auto-correlation function (ACF) value of the impulse response of the received wireless signal; determining a power spectrum density of said received wireless signal based on the ACF value; and selecting an algorithm for performing demodulation of the received wireless signal by utilizing the determined power spectrum density.

Abstract: Timing and frequency offset processing in sub-carriers is performed in an Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) receiver system. Sub-carriers are divided into two sub-sets, where the sub-sets contain an equal number of sub-carriers. Subsequently bad sub-carriers are removed, if present, from first sub-set of the sub-sets, and corresponding sub-carriers from a second sub-set of the sub-sets are also removed. Further, a phase difference on each sub-carrier from each sub-set is computed, and mean phase differences of each of the sub-sets are computed. Furthermore, frequency offset is computed by averaging the mean phase differences of the sets.

Abstract: An apparatus and method for WIC/LIC estimation without channel mode construction in a MediaFLO™ system comprising a receiver, a transmitter and transmission channel, wherein the method comprises receiving a signal comprising a MediaFLO™ mobile multimedia multicast system superframe comprising WIC/LIC symbols; setting a first sparseness index value of the digital signal to zero; setting a local copy WIC/LIC number of the digital signal to one; generating a local copy of all possible values of the WIC/LIC symbols corresponding to a WID/LID value from zero to fifteen; dividing the received WIC/LIC symbol values by a local copy WIC/LIC value corresponding to WIC/LIC number one; performing an IFFT of all the possible values of the WIC and LIC symbols; calculating a second sparseness index value of the IFFT of sixteen possible values of the WIC/LIC symbols; and extracting a WIC/LIC symbol from the digital signal corresponding to the second sparseness index.

Abstract: A technique of acquisition in a MediaFLO™ (Forward Link Only) mobile multimedia multicast system, wherein the method comprises receiving a superframe comprising a first digital symbol in a receiver operating in a first state of operation; assuming the first received digital symbol to be a Time Division Multiplexed (TDM) pilot symbol; calculating a first sparseness index of the first symbol; storing the first sparseness index; operating the receiver in a second state of operation; receiving a second digital symbol; calculating a second sparseness index for the second digital symbol; the receiver remaining in the second state of operation when the second sparseness index is greater than the first sparseness index, wherein the second digital symbol is assumed to be the TDM pilot symbol; and verifying that the last assumed TDM pilot symbol is the correct TDM pilot of the superframe.

Abstract: A DVB-H bit-interleave coded modulation/demodulation system and method includes a convolutional encoder; an interleaver operatively connected to the convolutional encoder; a quadrature amplitude modulation (QAM) mapper operatively connected to the interleaver; a channel component operatively connected to the QAM mapper; a QAM demapper operatively connected to the channel component; a de-interleaver operatively connected to the QAM demapper; and a Viterbi decoder operatively connected to the de-interleaver. Preferably, the interleaver comprises a bit-wise interleaver and a symbol-wise interleaver operatively connected to the bit-wise interleaver. Preferably, the de-interleaver comprises a bit-wise de-interleaver; and a symbol-wise de-interleaver operatively connected to the bit-wise de-interleaver. The de-interleaver may be adapted to decode a soft decision metric for any of a QPSK, 16QAM, and 64QAM modulation.

Abstract: A DC-DC converter and method of improving the efficiency of a DC-DC converter at low load current levels using pulse skipping modulation (PSM) with controllable burst duration NTclk, where Tclk is the clock cycle interval. As the average load current increases, the time between bursts decreases so that average inductor current matches the load current. The burst duration is kept around NTclk by controlling the duty cycle of the output switches. The higher the load current, the higher is the duty cycle of the output switches. No current sensing is needed. The optimum burst duration for best efficiency curve is a function of the load capacitor.

Abstract: A low noise, low power differential two-stage amplifier includes a first stage comprising a pair of electrical devices that sense an input signal difference across the pair of electrical devices; and a control feedback loop operatively connected to the first stage, wherein the first stage in combination with the control loop feedback is adapted to place an exact copy of the signal across a first pair of resistive components, wherein the first pair of resistive components are adapted to generate a differential signal current, wherein the control feedback loop is adapted to ensure that the differential signal current goes a second pair of resistive components to generate a voltage output. Preferably, the first and second pair of resistive components are in ratio to produce the exact copy of the signal with some gain at an output of the first stage.

Abstract: A noise shaping and voltage gain filtering third order electrical circuit and method comprises at least one pair of input resistors; a Frequency Dependent Negative Resistance (FDNR) filter positioned in between the at least one pair of input resistors; a feedback resistor; and an amplifier operatively connected to the feedback resistor and the at least one pair of input resistors, wherein as an electrical signal is introduced to the electrical circuit, the FDNR filter is adapted to filter signal blockers out of the electrical signal prior to the electrical signal reaching the amplifier for signal amplification, wherein the FDNR filter does not contribute noise to a signal-to-noise ratio (SNR) of the electrical signal, and wherein a transfer function of the FDNR filter is substantially elliptical in shape.

Abstract: A method of TMCC information acquisition in an ISDB-T/TSB receiver comprises detecting coarse frequency offset in the receiver to identify bins that have TMCC information; and acquiring TMCC and symbol number information from the identified bins. The detecting process may be conducted using different methods and the acquiring process may be conducted using different methods. The TMCC information acquisition method saves memory space and provides enhanced performance by using coarse frequency offset to identify the bins that have TMCC information and obtaining the TMCC and symbol number information from the identified bins.

Abstract: A modified classical Viterbi decoder which can take extrinsic information and output hard decisions. A modified Viterbi decoder is provided comprising a branch metric unit, the unit having a calculator; and a processor adapted to compute a revised branch metric by combining the initial branch metric and an additional weight parameter. The modified classical Viterbi decoder computes a branch metric by summing an initial branch metric and the additional weight parameter.

Abstract: A method of processing an in-phase signal component and a quadrature signal component of a low intermediate frequency (LIF) signal includes estimating and correcting an amplitude imbalance between a digitized in-phase signal component and a digitized quadrature signal component at a first point in time, and estimating and correcting a phase imbalance between the digitized in-phase signal component and the digitized quadrature signal component at a second point in time in response to the correcting process. The digitized in-phase signal component corresponds to the in-phase signal component at the first point in time and the digitized quadrature signal component corresponds to the quadrature signal component at the first point in time. The second point in the time is subsequent to the first point in time.

Abstract: A method of estimating coarse frequency offset of received symbols based on a received frequency domain sample at a kth sub-carrier of a 53rd Orthogonal Frequency Division Multiplexing (OFDM) data symbol in a jth time slot (TS) of a receiver in a China Multimedia Mobile Broadcasting (CMMB) mobile television network includes dividing a received sample, Ykj, into two sets of noise only tones and data plus noise tones Dkj, obtaining a received sample only if there is a coarse frequency offset mismatch between a transmitter and the receiver, dividing a summation of a power of the data plus noise tones by a summation of a power of the noise only tones to obtain ?kj, and estimating an integer coarse frequency offset estimate, ?{circumflex over (f)}Ij, of the received symbols when the ?kj is a maximum.

Abstract: A technique for decoding code packets of file delivery protocol (FDP) and file delivery control protocol (FDCP) messages, the FDP messages comprising fields having values used to generate an indices of a data packets, the FDCP messages comprising a value of a minimum number of code packets required, the code packets formed from a linear combination of the data packets of a file fragment, the method includes constructing data structures adapted to decode the code packets of the file fragment, the data structures comprising at least one of code nodes, a code graph, an inverse code graph, a data packet decode array, and a data packet decode order list, processing the FDP messages until a parameters required for decoding are extracted, and populating the inverse code graph with a reference to the code node.

Abstract: An apparatus and method of reducing a channel switching delay in TDM mobile television systems, and comprises receiving a data burst associated with channels for reception on a RF channel bandwidth received on a mobile television receiver, wherein the data burst comprises a plurality of RTP packets and a RTCP packet; buffering the data burst upon reception of a first RTP packet; synchronizing the buffered data burst to allow for reception of playable A/V data; and adjusting the synchronized buffered data burst upon reception of the RTCP packet. The method may further comprise performing the synchronizing upon reception of the RTCP packet. The method may further comprise inserting a null packet in the data burst prior to performing the buffering. The first RTP packet is preferably received prior to reception of the RTCP packet.

Abstract: A method and apparatus for estimating timing and frequency offsets in an ISDB-T and ISDB-TSB receiver. In different embodiments, the method comprises estimating timing and frequency offsets by different estimation processes; assigning weights to the timing and frequency offsets according to the channel condition; and calculating timing and frequency offsets using the estimates of timing and frequency offsets and the weights.

Abstract: A technique for providing stable tracking performance to an AGC loop circuit comprises amplifying a wideband radio frequency signal; detecting signals and blockers adjacent to the radio frequency signal; lowering a gain of the radio frequency signal; mixing a local oscillator signal with the radio frequency signal; shifting a frequency of the radio frequency signal from a radio frequency to an intermediate frequency; continuously varying a gain of the intermediate frequency signal; converting the intermediate frequency signal into a digital output signal; comparing the digital output signal with predefined thresholds comprising an upper threshold and a lower threshold; switching a post mixer amplifier (PMA) to a high gain state when an input of a variable gain amplifier (VGA) is greater than the upper threshold, and switching the PMA to a low gain state when an input of the VGA is lower than the lower threshold.