Patent application number | Description | Published |
20090028324 | METHOD AND SYSTEM FOR PROVIDING SCRAMBLED CODED MULTIPLE ACCESS (SCMA) - A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme. | 01-29-2009 |
20100098245 | METHOD AND SYSTEM FOR PROVIDING SPREAD SCRAMBLED CODED MULTIPLE ACCESS (SSCMA) - A spread scrambled multiple access (SSCMA) scheme is described. A first encoded bit stream of a first terminal is scrambled according to a first scrambling signature. A second encoded bit stream of a second terminal is scrambled according to a second scrambling signature. The first scrambled bit stream is spread to match a communication channel bandwidth. The second scrambled bit stream is spread to match the communication channel bandwidth. | 04-22-2010 |
20110033016 | METHOD AND APPARATUS FOR PROVIDING CARRIER SYNCHRONIZATION IN DIGITAL BROADCAST AND INTERACTIVE SYSTEMS - An approach is provided for supporting carrier synchronization in a digital broadcast and interactive system. A carrier synchronization module receives one or more signals representing a frame that includes one or more overhead fields (e.g., preamble and optional pilot blocks and one or multiple segments separated by pilot blocks). The module estimates carrier frequency and phase on a segment by segment basis and tracks frequency between segments. Carrier phase of the signal is estimated based upon the overhead field. Estimates carrier phase of random data field are determined based upon the estimated phase values from the overhead fields, and upon both the past and future data signals. Further, the frequency of the signal is estimated based upon the overhead fields and/or the random data field. The above arrangement is particularly suited to a digital satellite broadcast and interactive system. | 02-10-2011 |
20110103507 | SYSTEM AND METHOD FOR COMBINED PREDISTORTION AND INTERFERENCE CANCELLATION IN A SATELLITE COMMUNICATIONS SYSTEM - The present invention provides a communication system for use with a first source signal and a second source signal. The first source signal is on a first channel and includes M symbols, where M is an integer greater than 1. The second source signal is on a second channel and includes X symbols, where X is an integer greater than 1. The first channel is different from the second channel. The communication system includes a first modulator unit, a second modulator unit and an adder. The first modulator unit can generate a first modulated signal based on the first source signal and includes a first inter-symbol distortion estimating unit and a first stage predistortion unit. The second modulator unit can generate a second modulated signal based on the second source signal and includes a second inter-symbol distortion estimating unit and a predistortion unit. The adder can generate an added signal based on the first modulated signal and the second modulated signal. The first inter-symbol distortion estimating unit can generate a distorted symbol vector based on an estimate of a distortion of the first through (a−1)-th symbols and an estimate of a distortion of the (a+1)-th through M-th symbols, where 1≦a≦M. The first stage predistortion unit is operable to generate a predistorted symbol ã based on the symbol a of the first plurality of symbols and the distorted symbol vector. Further, a receiver unit can cancel interference in the received signals to account for adjacent channel interference. | 05-05-2011 |
20110258669 | SYSTEM AND METHOD FOR MULTI-CARRIER MULTIPLEXING - A transmitter is provided for use with a first input signal and a second input signal. The transmitter includes a first modulating portion, a second modulating portion and a multiplexing portion. The first modulating portion can output a first plurality of code blocks based on the first input signal, wherein each of the first plurality of code blocks has a first sequence number associated therewith and is modulated with a first modulation scheme. The second modulating portion can output a second plurality of code blocks based on the second input signal, wherein each of the second plurality of code blocks has a second sequence number associated therewith and is modulated with a second modulation scheme, and wherein the second modulation scheme is different than the first modulation scheme. The multiplexing portion can a third plurality of code blocks based on the first plurality of code blocks, the second plurality of code blocks and planning code block. The planning code block associates each of the third plurality of code blocks with a respective one of the first plurality of code blocks and the second plurality of code blocks. | 10-20-2011 |
20120121023 | SYSTEM AND METHOD FOR MULTI-CARRIER MULTIPLEXING - A system for a multiplexing scheme for wideband signals in a communications system is provided. A codeblock of a multiplexed datastream is decoded. The codeblock includes a flag indicating whether the codeblock contains a timeplan, signifying a multiplexing structure of the datastream. A determination is made whether the flag indicates the presence of the timplena, and, if so, the timeplan is acquired. In response to a determination that the codeblock does not contain the timeplan, a subsequent codeblock is determined, and decoded. Each codeblock includes a an indicator of a sequence position of the codeblock within a group of codeblocks of the datastream. The subsequent codeblock is determined based on one or more of a decode rate of the processor device and the sequence position indicator. A determination is made whether the flag of the first subsequent codeblock indicates the presence of the timeplan, and, if so, the timeplan is acquired. | 05-17-2012 |
20120195401 | SYSTEM AND METHOD FOR CORRELATING RECEIVED SIGNAL OVER TIME AND FREQUENCY - A system is provided for use with a frequency band including a transmission frequency and a received frequency. The transmission frequency includes a transmission signal having a transmitted unique word therein. The received frequency includes a received signal having a received unique word therein, wherein the received unique word had been received at a received time and at a received phase. The system includes a first sub-correlator, a second sub-correlator and a discrete Fourier transform device. The first sub-correlator can perform a first correlation of only a first portion of the received unique word with a corresponding first portion of the transmitted unique word over a plurality of instances of time and can output a first plurality of sub-correlation values. The second sub-correlator can perform a second correlation of only a second portion of the received unique word with a corresponding second portion of the transmitted unique word over the plurality of instances of time and can output a second plurality of sub-correlation values. The discrete Fourier transform device can perform a discrete Fourier transform over a plurality of frequencies within the frequency band on the first plurality of sub-correlation values and can perform a discrete Fourier transform over the plurality of frequencies within the frequency band on the second plurality of sub-correlation values. The first portion of the received unique word is different from the second portion of the received unique word. | 08-02-2012 |
20120198502 | METHOD AND APPARATUS FOR DATA RATE CONTROLLER FOR A CODE BLOCK MULTIPLEXING SCHEME - A receiver is used with third code blocks based on first code blocks, second code blocks, and a planning code block. The first code blocks are associated with a first sequence number and modulated with a first modulation scheme. The second code blocks are associated with a second sequence number and modulated with a second modulation scheme. The planning code block associates the third code blocks with the first code blocks and the second code blocks. The receiver includes a de-multiplexing portion, which includes a code block selector and a look up table, that outputs a de-multiplexed signal based on the third code blocks. The code block selector selects a code block from the third code blocks to output as the de-multiplexed signal based on entries in the look up table. The receiver also includes a recovery portion that outputs received code blocks based on the de-multiplexed signal. | 08-02-2012 |
20130223544 | SYSTEM AND METHOD FOR EFFICIENT FREQUENCY ESTIMATION IN BURST-MODE COMMUNICATION - Aspects of the invention provide a method of introducing pilot symbols for synchronization that minimizes overhead while allowing for a large frequency uncertainty by inserting the pilot groups non-periodically in burst communication systems. The pilot sequence could be used for establishing all synchronization, including timing, frequency and phase, or, alternatively, it could be used only for carrier phase and frequency estimation with some other means used for establishing start-of-burst timing. | 08-29-2013 |
20130223558 | SYSTEM AND METHOD FOR CONSTRUCTING UNIQUE WORD SETS FOR EFFICIENT DETECTION USING ORTHOGONAL FUNCTIONS - A system and method of construction of unique word sets together with an efficient method of implementing correlation with the members of the set is presented. The set of UWs is constructed by breaking a UW sequence in to equal length segments, and then multiplying this vector by an orthogonal matrix. First an arbitrary vector U is chosen of length K for a set of N UWs. Then a matrix H of size N×N is chosen. The columns of H are then repeated L times to form a matrix H′. The set of N UW consists of the rows of H′U | 08-29-2013 |
20140029704 | SYSTEM AND METHOD FOR CORRELATING RECEIVED SIGNAL OVER TIME AND FREQUENCY - A system is provided for use with a frequency band including a transmission frequency and a received frequency. The transmission frequency includes a transmission signal having a transmitted unique word therein. The received frequency includes a received signal having a received unique word therein, wherein the received unique word had been received at a received time and at a received phase. The system includes a first sub-correlator, a second sub-correlator and a discrete Fourier transform device. The first sub-correlator can perform a first correlation of only a first portion of the received unique word with a corresponding first portion of the transmitted unique word over a plurality of instances of time and can output a first plurality of sub-correlation values. The second sub-correlator can perform a second correlation of only a second portion of the received unique word with a corresponding second portion of the transmitted unique word over the plurality of instances of time and can output a second plurality of sub-correlation values. The discrete Fourier transform device can perform a discrete Fourier transform over a plurality of frequencies within the frequency band on the first plurality of sub-correlation values and can perform a discrete Fourier transform over the plurality of frequencies within the frequency band on the second plurality of sub-correlation values. The first portion of the received unique word is different from the second portion of the received unique word | 01-30-2014 |
20140201602 | METHOD AND SYSTEM FOR PROVIDING SCRAMBLED CODED MULTIPLE ACCESS (SCMA) - A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme. | 07-17-2014 |
20140269955 | SYSTEM AND METHOD FOR ESTIMATING AN AMPLIFIER OPERATING POINT USING MEASUREMENTS AT A RECEIVER - An apparatus includes a receiver component, a first signal processing component and a second signal processing component. The receiver component can receive a transmission signal, wherein the received transmission signal reflects an encoded and modulated initial source signal, amplified via a source transmitter, and transmitted over one or more channels of a wireless communications network. The first signal processing component can process the received transmission signal to generate a replica transmission signal that estimates the encoded and modulated initial source signal. The second signal processing component can determine an optimal parametric function for modeling the source transmitter, wherein the determination of the optimal parametric function comprises an iterative non-linear curve-fitting process, and wherein the optimal parametric function reflects one or more parameters of the source transmitter. | 09-18-2014 |
20140337896 | METHOD AND APPARATUS FOR DATA RATE CONTROLLER FOR A CODE BLOCK MULTIPLEXING SCHEME - A receiver is used with third code blocks based on first code blocks, second code blocks, and a planning code block. The first code blocks are associated with a first sequence number and modulated with a first modulation scheme. The second code blocks are associated with a second sequence number and modulated with a second modulation scheme. The planning code block associates the third code blocks with the first code blocks and the second code blocks. The receiver includes a de-multiplexing portion, which includes a code block selector and a look up table, that outputs a de-multiplexed signal based on the third code blocks. The code block selector selects a code block from the third code blocks to output as the de-multiplexed signal based on entries in the look up table. The receiver also includes a recovery portion that outputs received code blocks based on the de-multiplexed signal. | 11-13-2014 |
20140341118 | PLS HEADER CODING FOR EFFICIENT SIGNALING OF MODULATION AND CODING SCHEMES FOR BROADBAND SATELLITE COMMUNICATIONS SYSTEMS - An approach is provided for an improved coding approach for efficient header signaling in broadband communications networks, to provide support of expanded modulation and coding scheme sets that facilitate an expansion of the operational ranges of user terminals within such networks and finer granularity within such operational ranges. A mode indicator field of a frame header identifies a modulation/coding mode applied to a data payload of the data frame. The modulation/coding mode is one of either a first or second set of modulation/coding modes. The mode indicator field is encoded and modulated. When the modulation/coding mode is one of the first set, the modulation of the encoded mode indicator field is applied in a first mode, and when the modulation/coding mode is one of the second set, the modulation of the encoded mode indicator field is applied in a second mode. | 11-20-2014 |
20140369440 | SYSTEM AND METHOD FOR EFFICIENT FREQUENCY ESTIMATION IN BURST MODE COMMUNICATION - Aspects of the invention provide a method of introducing pilot symbols for synchronization that minimizes overhead while allowing for a large frequency uncertainty by inserting the pilot groups non-periodically in burst communication systems. The pilot sequence could be used for establishing all synchronization, including timing, frequency and phase, or, alternatively, it could be used only for carrier phase and frequency estimation with some other means used for establishing start-of-burst timing. | 12-18-2014 |