Abstract: Enhancing stream layer transmission for a MediaFLO mobile multimedia multicast system comprising a transmitter and a receiver includes sending a plurality of multicast logical channels (MLC) forming a data frame from the transmitter, wherein each MLC comprises multimedia data streams comprising a stream 0, 1, and 2 data packet, and parity data bits; switching, by the transmitter, an order of the multimedia data streams of the MLC transmitted by the transmitter; sending a signal to the receiver from the transmitter to specify a mode of transmission of the MLC, wherein the mode of transmission comprises an order of transmitting the data packets of the MLC; inserting, by the transmitter, a flag in control information transmitted in the stream 0 data packets; decoding, by the receiver, the flag to determine the mode of transmission; and performing, by the receiver, a CRC of the stream 0 data packet.

Abstract: A receiver for use in a wireless network comprising a communications channel and a method of allocating deinterleaver memory usage in the receiver, wherein the receiver comprises a processor adapted to organize subchannels of the communications channel and set a number (N) of data bits per soft decision, wherein the soft decision is represented by N data bits; an address decoder adapted to decode the subchannels; a demapper adapted to receive QAM symbols and demap the QAM symbols to soft decisions; a deinterleaver adapted to perform deinterleaving on the soft decisions, wherein the deinterleaver comprises a memory component having a storage size that is a function of the number (N) of bits per soft decision; and a Viterbi decoder adapted to decode the deinterleaved soft decisions.

Abstract: One embodiment provides a method of performing packet identifier (PID) filtering of a digital video broadcasting-handheld (DVB-H) transport stream and includes processing a PID and a continuity counter (CC) sequence of the DVB-H transport stream, computing a number of mismatched bits between the PID and a desired PID, proceeding to a start of a reset state on a first-in-first-out (FIFO) queue of the DVB-H transport stream when a FIFO buffer becomes full, determining if a number of mismatched bits of a first packet in the FIFO buffer is less than a first threshold value, and proceeding to a start of a run algorithm state only if the number of mismatched bits of the first packet in the FIFO buffer is less than the first threshold value and if there is a valid CC sequence that includes the first packet.

Abstract: A data transmission system and method for DVB-H signals for enhancing data robustness of a DVB-H receiver in additive white Gaussian noise (AWGN) channels includes transmitting IP datagrams from a DVB-H transmitter to the DVB-H receiver; applying a MPE section and a FEC section to the transmitted IP datagrams; mapping the transmitted IP datagrams to TS packets; aligning boundaries of the transmitted IP datagrams to a given number of TS packets; fixing a size of the IP datagrams to a known value at the DVB-H receiver; and extracting the IP datagrams from the DVB-H receiver.

Abstract: A receiver for use in a pilot-aided OFDM system and a method of performing channel length estimation of a channel in a wireless communication system includes using transmitted and received wireless signals to estimate a channel carrier function vector at continuous and scattered pilot positions of consecutive OFDM symbols; performing time-domain interpolation by (i) upsampling the estimated the channel carrier function vectors at the scattered pilot positions by inserting zeros in between estimated scattered pilot positions, and (ii) filtering the upsampled vectors using a finite impulse response filter comprising a filter bank comprising a plurality of filters; mapping the channel carrier function vector to only one of the filters in the filter bank located in the finite impulse response filter, wherein the mapping causes noise reduction and enhanced channel estimation thereby increasing a maximum Doppler frequency in the channel.

Abstract: Detecting Null symbols in a video data frame comprises sending OFDM symbols through a sliding windowed correlation process having a correlation window length proportional to a cyclic prefix length and a delay equal to a FFT size of the symbols, wherein output peaks of the process occur where two similar portions of the symbols coincide; checking peaks in windows sized equal to a duration of a symbol; determining whether the peaks are located in the middle of the windows; determining whether a shift has occurred in the location of the peak of a current window compared to in a second immediately previous window; determining whether the peak in a first immediately previous window is weak compared to that in a second immediately previous window; and declaring that a Null symbol exists in the first previous window when the shift has occurred and the determination of a weak peak exists.

Abstract: A method and system for coherent detection in which a OFDM symbol is multiplied by the complex conjugate of the previous OFDM symbol, which is obtained by one OFDM symbol delay and a complex conjugation circuit. This soft decision is passed through a QPSK slicer to obtain a hard decision. The soft decision is then divided by the hard decisions. The channel phase change between the two OFDM symbols is then obtained. For the first OFDM symbol, the channel is computed. A channel estimate for each ODFM symbol is computed from corresponding channel estimates and channel phase difference estimates. The channel phase difference between each two OFM symbols is computed. The channel phase difference is passed through an exponent operation and multiplied by the soft decision to obtain a refined soft decision that is then passed through another QPSK slicer to obtain the final hard decision.

Abstract: FEC frame synchronization in a DAB-IP system comprising FEC frames includes receiving FEC packets each comprising a FEC packet header and a FEC data field comprising padding bytes at an end of a last FEC packet received; comparing a received FEC packet header with a known FEC packet header until a number of bit errors in the received FEC packet header is less than or equal to a predetermined amount; and matching the received FEC packet header and the padding bytes until at least one of the following actions occur thereby resulting in receiver locking: a number of successive FEC packet headers mismatches in the received FEC packet header; a predetermined number of FEC packets end without padding matching; and FEC packet header and padding matching occurs. The received FEC packets are tracked after receiver locking has occurred to ensure FEC parity packets are positioned properly in the FEC frames.

Abstract: ICI canceling in an OFDM system includes taking a FFT of a wireless electrical signal to produce an OFDM signal; estimating a DC component of a frequency-selective channel in the OFDM system; obtaining an initial estimate of data symbols associated with data bits of the OFDM signal; correcting the data bits with a Viterbi decoder; encoding the corrected data bits to acquire corrected data symbols; re-estimating the DC component of the frequency-selective channel using the corrected data symbols; filtering the corrected data symbols and sub-carrier of the frequency-selective channel; calculating a first order differential function of the frequency-selective channel based on successive ones of the corrected data symbols; removing an ICI component from the calculated first order differential function; and re-estimating the data symbols as a function of the removed ICI component. The filtering occurs using a low pass filter comprising a bank of eight filters.

Abstract: A system and method of using recursive cyclic redundancy check (CRC)+forward error correction (FEC) for enhancing the channel coding gain for a DVB-H receiver, and using a physical (PHY) Reed-Solomon (RS) decoder+FEC to achieve better coding gain. The system and method utilize a dual mode RS decoder (erasure mode and error mode) for FEC decoding. The PHY RS is used to provide smaller granularity for FEC. The system includes a cache memory management scheme for implementing the recursive CRC/RS+FEC in very large scale integrated circuit chip (VLSI) hardware.

Abstract: A receiver and method of enhancing transmitted data signals in a wireless communications system includes wirelessly transmitting and receiving a data signal over a wireless channel in the communications system; providing known channel parameters corresponding to the wireless channel; expressing the data signal as an input data vector; replacing indexes in the input data vector having a magnitude greater than one into indexes in the input data vector having a unit norm; creating an output data vector; and calculating a dot product of (i) the input data vector comprising replaced indexes; and (ii) the output data vector, wherein the calculating process equalizes the data signal received by a receiver in the presence of Doppler frequency shifts of the data signal.

Abstract: Transmitting data in a digital video broadcasting for handheld (DVB-H) receiver comprises a transport stream (TS) demultiplexer adapted to extract internet protocol (IP) datagrams from TS data packets; a packet identifier (PID) filter adapted to extract the TS data packets based on the PIDs of the TS data packets; a Multi Protocol Encapsulation-Forward Error Correction (MPE-FEC) random access memory (RAM) unit operatively connected to the TS demultiplexer; a Reed-Solomon decoder operatively connected to the MPE-FEC RAM unit; an IP to TS encapsulator operatively connected to the MPE-FEC RAM unit; a TS multiplexer operatively connected to each of the PID filter and the IP to TS encapsulator, wherein the TS multiplexer is adapted to combine both DVB-Terrestrial (DVB-T) and DVB-H TS data packets into a single combined TS data packet; and a host interface operatively connected to the TS multiplexer.

Abstract: A system and method for performing stepped automatic gain control (AGC) for orthogonal-frequency-division-multiplexing (OFDM) applications comprises a radio frequency (RF) tuner and an OFDM demodulator operatively connected to the RF tuner, the OFDM demodulator comprising logic circuitry adapted to (i) detect OFDM symbols from a stream of data; (ii) detect boundaries of the OFDM symbols; (iii) detect a cyclic prefix duration of data values associated with the OFDM symbols; and (iv) provide a feedback to the RF tuner of the information pertaining to the boundaries of the OFDM symbols and the cyclic prefix duration.

Abstract: A method of creating a visual program guide for use on a TDM mobile TV receiver comprises receiving a RF signal associated with a TV channel; demodulating all of the received RF signals associated with the TV channels; decoding all of the demodulated received RF signals corresponding to all the TV channels simultaneously; and creating the visual program guide as a consolidated view of each of the decoded TV channels, wherein the simultaneous decoding of the demodulated received RF signals significantly reduces a power consumption level and a memory utilization level in the receiver.

Abstract: A receiver and method of enhancing transmitted data signals in a wireless communications system includes wirelessly transmitting and receiving a data signal over a wireless channel in the communications system; providing known channel parameters corresponding to the wireless channel; expressing the data signal as an input data vector; replacing indexes in the input data vector having a magnitude greater than one into indexes in the input data vector having a unit norm; creating an output data vector; and calculating a dot product of (i) the input data vector comprising replaced indexes; and (ii) the output data vector, wherein the calculating process equalizes the data signal received by a receiver in the presence of Doppler frequency shifts of the data signal.

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, 16 QAM, and 64 QAM modulation.

Abstract: A DVB-H transmitter having a plurality of video encoders each having a variable bit rate associated with IP datagrams for each television program broadcast by one RF channel. A method is also provided for statistical multiplexing of video channels for DVB-H mobile TV applications, wherein the method includes jointly configuring a plurality of video encoders each having a variable bit rate associated with IP datagrams for each television program broadcast by one RF channel.

Abstract: A data transmission system and method for DVB-H signals for enhancing data robustness of a DVB-H receiver in additive white Gaussian noise (AWGN) channels includes transmitting IP datagrams from a DVB-H transmitter to the DVB-H receiver; applying a MPE section and a FEC section to the transmitted IP datagrams; mapping the transmitted IP datagrams to TS packets; aligning boundaries of the transmitted IP datagrams to a given number of TS packets; fixing a size of the IP datagrams to a known value at the DVB-H receiver; and extracting the IP datagrams from the DVB-H receiver.

Abstract: Carrier frequency offset (CFO) estimation from preamble symbols. Any communication receiver may be adapted to perform the CFO estimation. The CFO estimation is performed using a low complexity, high accuracy CFO estimation method. The operation may be described as follows: each element of a received sequence is divided by the corresponding preamble element, the resulting sequence is divided into N subgroups, and each subgroup is then averaged. The phase differential of the resulting sequence is computed, averaged, and used to compute an estimate of the carrier frequency offset. This approach to performing CFO estimation is of relatively high estimation accuracy and of relatively low computational complexity.

Abstract: A communication device constructed according to the present invention detects impulse noise in a preamble sequence. In detecting impulse noise in the preamble sequence the communication device first receive a preamble sequence that includes a plurality of preamble symbols. The communication device then divides the plurality of preamble symbols by at least one known preamble symbol to produce a plurality of preamble gains and/or a plurality of preamble phases corresponding to the plurality of preamble symbols. Finally, the communication device determines, based upon the plurality of preamble gains and/or the plurality of preamble phases, that at least one preamble symbol has been adversely affected by a impulse noise. The communication device may discard at least one preamble symbol that has been adversely affected by impulse noise from the plurality of preamble symbols.