Newport Media, Inc.

Broadcom Corporation

Nabil R Yousef

Thomas J Kolze

Jun Ma

Jonathan S Min

Bruce Joseph Currivan

Gottfried Ungerboeck

Ricardo Merched

Chaoliang T Chen

Edward Youssoufian

Xiaoyu Fu

Randall Bret Perlow

Aly Mamdouh Ismail

Waleed M Younis

Charles Brooks

Tracy C Denk

Philip Treigherman

Janakan Sivasubramaniam

Mirette Sadek

Elsayed Ahmed

Frank Carr

Daniel Harvey Howard

Yongru Gu

Bin Xu

Li Liu

Tianmin Liu

Ahmed Ibrahim Khalil

William Ngai

Ahmed Ragab

Elsayed Ahmed Elsayed

Samer Sarhan

Mahmoud H Ismail

Waleed Youris

Maged F Barsoum

A technique for estimating a carrier frequency offset and a timing offset in aMediaFLO&#x2122; (Forward Link Only)communicationsystem, wherein the method comprisesincludesreceiving 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.

Robust fine frequency and time estimation in mobile receivers

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.

Robust PID filtering for DVB-H

A method of estimating coarse frequency offset of received symbols based on a received frequency domain sample at a ksub-carrier of a 53Orthogonal Frequency Division Multiplexing (OFDM) data symbol in a jtime slot (TS) of a receiver in aChina Multimedia Mobile Broadcasting (CMMB) mobile televisioncommunicationnetwork includes dividing a received sample, Y, into two sets of noise only tones and data plus noise tones D, 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 &#x39b;, and estimating an integer coarse frequency offset estimate, &#x394;{circumflex over (f)}, of the received symbols when the &#x39b;is a maximum.

Coarse carrier frequency offset estimation for a receiver

A system for mitigating impairment in a communication system includes a delay block, a signal level block, a moving average window block, an impulse noise detection block, and a combiner. The delay block receives and delays each chip of a plurality of chips in a spreading interval. The signal level block determines a signal level of each chip of the plurality of chips in the spreading interval. The moving average window block determines a composite signal level for a chip window corresponding to the chip. The impulse noise detection block receives the signal level, receives the composite signal level, and produces an erasure indication for each chip of the plurality of chips of the corresponding chip window. The combiner erases chips of the plurality of chips of the spreading interval based upon the erasure indication.

Chip blanking and processing in SCDMA to mitigate impulse and burst noise and/or distortion

A communication system performs burst noise cancellation. A transmitter produces and transmits a spread signal that comprises at least one known-value symbol spread by a plurality of non data-carrying orthogonal codes and data symbols spread by at least one data-carrying orthogonal code. The transmitter transmits the spread signal across a communication link that introduces burst noise. A burst noise detector determines burst noise affected chips of the orthogonal codes. A weight computation functional block calculates a plurality of complex-valued combining weights based upon the burst noise affected chips. A vector de-spreader and a linear combiner operate in combination to use the plurality of non data-carrying orthogonal codes, the at least one data-carrying orthogonal code, and the plurality of complex-valued combining weights to de-spread the received spread signal to produce the data symbols with the burst noise substantially removed.

Cancellation of burst noise in a communication system with application to S-CDMA

Enhancing a stream layer transmission for a MediaFLO&#x2122; mobile multimedia multicast system comprising a transmitter and a receiver. Code word (CW) computations are performed on a current channel being accessed by the receiver. A favorite channel that a user is statistically mostly likely to switch to on the receiver at any particular time is anticipated. The Overhead Information Symbols (OIS) for each favorite channel is periodically monitored. The receiver remains in a sleep mode while data bursts are received from non-favorite channels, and then wakes up during data bursts of the favorite channel. The same CW computations are performed on the favorite channel as were being performed on the current channel. A cyclic redundancy check (CRC) is performed once the CW computations are performed upon selecting the favorite channel.

Fast channel switching for encrypted mobile multimedia multicast system

Successive interference canceling for CDMA. ICI may result from a signal's multi-path effects, or by filtering/suppression of some of the component energy of the signaling waveforms. Energy component attenuation destroys orthogonality of CDMA symbols thereby causing ICI. An ICF suppresses frequency domain portions (attenuates ingress), but also introduces ICI. Following the ICF, the signal is de-spread, sliced, re-spread and convolved with the ICF echoes (except first tap echoes). Convolving re-spread hard decisions with delayed ICF taps is equivalent to partially re-modulating the first-pass hard decisions to efficiently 'add-back-in' the signal energy which was blanked/subtracted by the ICF. Alternatively, parameter estimation de-rotates and re-rotates soft symbols and hard decisions, respectively, compensating for undesirable symbol rotation. The convolved signal is subtracted from a delayed version of the ICF output signal. If desired, this process may be repeated successively to enhance the accuracy of the obtained data decisions in the next stage.

Successive interference canceling for CDMA

A system and method of transmitting video in a time division multiplexing (TDM) system, wherein the method comprises identifying a video reference frame from a series of video frames; encoding a difference between the video reference frame and a video non-reference frame; placing the video reference frame at a beginning of a data burst; transmitting the series of video frames and the data burst from a transmitter to a mobile TV receiver; and the mobile TV receiver immediately locating the video reference frame upon receipt of the data burst. The method may further comprise the mobile TV receiver decoding the series of video frames. Additionally, the placing process results in a substantially non-existent channel switching delay in the mobile TV receiver. Moreover, the method may further comprise placing exactly one video reference frame at the beginning of the data burst. Preferably, the TDM system comprises a mobile TV system.

Physical layer aware video encoding for mobile TV applications

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.

Technique for tuner automatic gain control circuit for mobile television applications

An apparatus and method for estimating Doppler frequency in a wireless communication network, wherein the method comprises determining a first correlation coefficient (c) between a currently received Orthogonal Frequency Division Multiplexed (OFDM) symbol and an OFDM symbol received previous to the currently received OFDM symbol, and a second correlation coefficient (c) between the currently received OFDM symbol and an OFDM symbol received immediately previous to the OFDM symbol received previous to the currently received OFDM symbol; performing a leaky integration across OFDM symbols of the resulting first and second correlation coefficients (c, c) to obtain an estimate of the first and second correlation coefficients; dividing the second correlation coefficient (c) by the first correlation coefficient (c) to obtain a correlation coefficient ratio; and using the correlation coefficient ratio as an estimate of the Doppler frequency in the wireless communication system.

Doppler frequency estimation in wireless communication systems

A technique for iterative decoding between turbo and Reed Solomon (RS) decoders for improving bit error rate (BER) and packet error rate (PER) in a receiver in a wireless communication system comprises receiving data samples comprising turbo encoded packets and RS code words at the receiver; decoding turbo encoded packets of the received data samples using a turbo decoder; decoding RS code words of the received data samples using a RS decoder; feeding the RS decoded data to turbo decoder to perform a plurality of iterations; and correcting data errors present in the received data samples.

Iterative decoding between turbo and RS decoders for improving bit error rate and packet error rate

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.

Fast audio/visual reception in DVB-H systems

Estimating a current location of a receiver in a MediaFLO&#x2122; (Forward Link Only) mobile multimedia multicast system comprises receiving digital signals comprising a MediaFLO&#x2122; superframe comprising orthogonal frequency division multiplexing (OFDM) symbols; performing slotprocessing of each medium access control (MAC) time unit of a data channel to identify a transmitter identity (TxID) of each transmitter; identifying corresponding geographical coordinates of each TxID; regenerating the digital signals for each of the transmitters using a local-area differentiator (LID) and a wide-area differentiator (WID) of the transmitters; dividing the digital signals by the corresponding regenerated transmitted signal to obtain channel estimates between the receiver and the corresponding transmitters; detecting a first peak in the channel estimates to determine a distance between the receiver and the corresponding transmitters; calculating a time difference of arrival of the digital signals; and estimating a current location of the receiver.

Method and apparatus for locating mobile multimedia multicast system capable wireless devices

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.

Growing community of inventors

Foothill Ranch, CA, United States of America

Nabil R Yousef