Patent application number | Description | Published |
20080232440 | CHIP BLANKING AND PROCESSING IN SCDMA TO MITIGATE IMPULSE AND BURST NOISE AND/OR DISTORTION - 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. | 09-25-2008 |
20080244246 | INTEGRATED MPE-FEC RAM FOR DVB-H RECEIVERS - A MPE-FEC memory chip and method for use in a DVB-H receiver, wherein the memory chip comprises a TS demux; a RS decoder; a system bus; and a RAM unit adapted to simultaneously interface to the TS demux, the RS decoder, and the system bus through time-multiplexing, wherein the RAM unit is adapted to (i) access multiple-words per clock cycle, and (ii) cache write and read accesses to reduce memory access from the TS demux and the system bus, and wherein the RAM unit is adapted to be clocked at a speed higher than an interfacing data-path to increase an effective throughput of the RAM unit. The RAM unit may comprise multiple RAM sub units, wherein while a first RAM sub unit is clock gated, the remaining multiple RAM sub units are accessible. | 10-02-2008 |
20080291980 | CANCELLATION OF INTERFERENCE IN A COMMUNICATION SYSTEM WITH APPLICATION TO S-CDMA - Cancellation of interference in a communication system with application to S-CDMA. A relatively straight-forward implemented and computationally efficient approach of selecting a predetermined number of unused codes is used to perform weighted linear combination selectively with each of the input spread signals in a multiple access communication system. If desired, the predetermined number of unused codes is always the same in each implementation. Alternatively, the predetermined number of unused codes is selected from within a reordered code matrix using knowledge that is shared between the two ends of a communication system, such as between the CMs and a CMTS. While the context of an S-CDMA communication system having CMs and a CMTS is used, the solution is generally applicable to any communication system that seeks to cancel narrowband interference. Several embodiments are also described that show the generic applicability of the solution across a wide variety of systems. | 11-27-2008 |
20080298394 | COMPACT MPE-FEC ERASURE LOCATION CACHE MEMORY FOR DVB-H RECEIVER - Location cache memory architectures that only require 32 Kbits or less per frame to store erasure information with simple address mapping to the main MPE-FEC RAM for easy column-wise and row-wise access. Alternative architectures are designed to greatly reduce the size and logic complexity of the MPE-FEC erasure cache memory. Two architectures reduce the erasure cache size down to 32 Kbits and 28 Kbits, correspondingly, without introducing additional erasure locations, while another architecture further reduces the required memory size down to 16K, 8K, 4K, or 2K bits with a slight increase in the total erasure locations. All architectures group the data in MPE-FEC frame memory into blocks of 2 | 12-04-2008 |
20080298437 | CANCELLATION OF BURST NOISE IN A COMMUNICATION SYSTEM WITH APPLICATION TO S-CDMA - 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. | 12-04-2008 |
20100034220 | Successive interference canceling for CDMA - 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. | 02-11-2010 |
20100111141 | Cancellation of burst noise in a communication system with application to S-CDMA - 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. | 05-06-2010 |
20100229075 | CHIP BLANKING AND PROCESSING IN SCDMA TO MITIGATE IMPULSE AND BURST NOISE AND/OR DISTORTION - 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. | 09-09-2010 |
20110002242 | Sparse channel equalization - Sparse channel equalization may be achieved by receiving a signal via a multi-path communication channel. The equalization then continues by extracting sparse information regarding the multiple path communication channel from the signal. Such sparse information generally indicates the position of the signals received via each of the multiple paths. The equalization then continues by estimating a channel response of the multiple path communication channel based on the sparse information. The equalization then continues by generating equalization taps (or coefficients) based on the channel response. The equalization then continues by equalizing the signal based on the equalization taps. | 01-06-2011 |
20120230374 | Chip blanking and processing in SCDMA to mitigate impulse and burst noise and/or distortion - 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. | 09-13-2012 |