1616 results about "Error ratio" patented technology

A method for controlling errors in a wireless link layer using a simultaneous multiple copy scheme and an adaptive forward error correction (FEC) scheme in a wideband wireless communication is provided. The method for controlling errors in a link layer in wideband wireless communication using an automatic repeat request (ARQ) scheme, in which a wideband wireless channel is used for communication between a first node and a second node, includes the steps of (a) estimating the error ratio of a forward (a direction in which a cell is transmitted from the first node to the second node) channel using the state of a backward (a direction in which a cell is transmitted from the second node to the first node) channel, and transmitting a cell, in which a forward error correction (FEC) code having an encoding ratio that varies depending on the estimated error ratio is included in a protocol data unit (PDU) of a wireless link layer, through the forward channel and (b) re-transmitting the copy of a cell transmitted in the step (a), when feedback information that indicates that an error exists in the cell transmitted in the step (a) is received through the backward channel. It is possible to reduce the number of times of re-transmission by improving the probability of correcting forward errors using more error controlling bits as the state of the channel is worse and to minimize the waste of resources using less error controlling bits as the state of the channel is better, to thus obtain the optimal performance and guarantee the minimum delay time.

A system for configuring solid-state storage devices comprises a solid-state storage device and an error correction code (ECC) selection system. The ECC selection system is configured to automatically select a set of error correction code based on an error rate of the storage device. The ECC selection system is further configured to install the selected set of error correction code in the solid-state storage device.

The present invention is a method, circuit and system for determining a reference voltage. Some embodiments of the present invention relate to a system, method and circuit for establishing a set of operating reference cells to be used in operating (e.g. reading) cells in an NVM block or array. As part of the present invention, at least a subset of cells of the NVM block or array may be read using each of two or more sets of test reference cells, where each set of test reference cells may generate or otherwise provide reference voltages at least slightly offset from each other set of test reference cells. For each set of test reference cells used to read at least a subset of the NVM block, a read error rate may be calculated or otherwise determined. A set of test reference cells associated with a relatively low read error rate may be selected as the set of operating reference cells to be used in operating (e.g. reading) other cells, outside the subset of cells, in the NVM block or array. In a further embodiment, the selected set of test reference cells may be used to establish an operating set of reference cells having reference voltages substantially equal to those of the selected test set.

Disclosed is an apparatus and method for adaptively allocating transmission power for beamforming combined with orthogonal space-time block codes (OSTBC) in a distributed wireless communication system, the apparatus comprising: a plurality of sub-arrays for beamforming, which are geographically distributed and each of which comprises a plurality of distributed antennas placed in random groups; and a central processing unit for identifying performances of subsets by applying a predetermined power allocation scheme according to subsets which can be obtained by combining the sub-arrays, by means of a Nakagami fading parameter and information about large-scale fading of each of the sub-arrays, fed back from a receiving party, for determining a subset having a best performance as an optimal subset according to the identified performances, and for performing power allocation based on the subset set as the optimal subset.

A smart memory system preferably includes a memory including one or more memory chips, and a processor including one or more memory processor chips. The system may include a smart memory controller capable of performing a bit error rate built-in self test. The smart memory control may include bit error rate controller logic configured to control the bit error rate built-in self test. A write error rate test pattern generator may generate a write error test pattern for the bit error rate built-in self test. A read error rate test pattern generator may generate a read error test pattern for the built-in self test. The smart memory controller may internally generate an error rate timing pattern, perform built-in self test, measure the resulting error rate, automatically adjust one or more test parameters based on the measured error rate, and repeat the built-in self test using the adjusted parameters.

Memory cells are programmed and read, at least M=3 data bits per cell, according to a valid nonserial physical bit ordering with reference to a logical bit ordering. The logical bit ordering is chosen to give a more even distribution of error probabilities of the bits, relative to the probability distributions of the data error and the cell state transition error, than would be provided by the physical bit ordering alone. Preferably, both bit orderings have 2M−1 transitions. Preferably, the logical bit ordering is evenly distributed. The translation between the bit orderings is done by software or hardware.

Various read level control apparatuses and methods are provided. In various embodiments, the read level control apparatuses may include an error control code (ECC) decoding unit for ECC decoding data read from a storage unit, and a monitoring unit for monitoring a bit error rate (BER) based on the ECC decoded data and the read data. The apparatus may additionally include an error determination unit for determining an error rate of the read data based on the monitored BER, and a level control unit for controlling a read level of the storage unit based on the error rate.

The invention provides an adaptive frequency hopping spread-spectrum (FHSS) transmission system and method, which efficiently utilizes available transmission bandwidth, whilst providing robustness to jamming techniques in wireless communication systems. The proposed technique operates by transmitting a wide-band signal over multiple, single-carrier, parallel transmission subbands, which may occupy non-contiguous frequency regions. The proposed scheme exhibits significant gain in error rate performance, as compared to a data rate equivalent single-subband system in the presence of signal jamming and / or interference without a reduction in the transmission data rate nor an increase in transmitter power. In addition, the proposed system and method are adaptive and enable more efficient use of the available bandwidth for communicating, thus increasing the overall bandwidth utilization of the system.

A radio bearer (RB) configuration to process packets in a single radio bearer. The RB configuration comprising: a first entity to split a received single packet stream into at least two packet sub-streams; and at least two second entities having respectively different modes for a single RB, each second entity to process each packet sub-stream split by the first entity. A method of processing packets in a single RB, comprising: receiving a single packet stream from an upper protocol layer; determining a characteristic of each packet in the received single packet stream; and splitting the determined packets into two different sub-streams, each sub-stream having different delay and / or error rate requirements.

A transmission terminal measures an error rate by periodically transmitting an error rate measuring packet to all transmission channels and all transmission paths. Content to be transmitted is classified, so that a transmission channel of the best transmission quality is assigned to content requiring real-timeness and a wide transmission bandwidth. According to the type of the content, a required communication protocol is selected to perform processing thereof. The transmission bandwidth for the content requiring a wide transmission bandwidth is assigned at a peak rate, while the transmission bandwidth for the content requiring a narrow transmission bandwidth is assigned at an average rate.

A base station has a time correlation calculating unit for estimating a variation-with-time characteristic of radio link quality using radio downlink quality information reported by a mobile station, a target error rate setting unit for changing over a target error rate adaptively using this variation-with-time characteristic, and an MCS decision unit for deciding a modulation scheme and / or encoding rate, in such a manner that packet error rate becomes equal to the target error rate, using the radio link quality information as well as reception success / failure information reported by the mobile station. The base station transmits a packet based upon the modulation scheme and / or encoding rate decided.

A method and apparatus for sorting particles moving through a closed channel system of capillary size comprises a bubble valve for selectively generating a pressure pulse to separate a particle having a predetermined characteristic from a stream of particles. The particle sorting system may further include a buffer for absorbing the pressure pulse. The particle sorting system may include a plurality of closely coupled sorting modules which are combined to further increase the sorting rate. The particle sorting system may comprise a multi-stage sorting device for serially sorting streams of particles, in order to decrease the error rate.

A system and method for generating transmit weighting values for signal weighting that may be used in various transmitter and receiver structures is disclosed herein. The weighting values are determined as a function of frequency based upon a state of a communication channel and the transmission mode of the signal. In variations, weighting of the weighted signal that is transmitted through each of a plurality of antennas is carried out with one of a corresponding plurality of transmit antenna spatial weights. In these variations, a search may be conducted over various combinations of transmit weighting values and transmit antenna spatial weights in order to find a weight combination that optimizes a performance measure such as the output signal-to-noise ratio, the output bit error rate or the output packet error rate.

An adaptive quality control loop for link rate adaptation based on modulation and / or coding schemes (also referred to as "MCS levels") and one or more spreading codes that adaptively selects channel condition thresholds in real-time without measuring all the factors that affect selecting optimal channel condition thresholds. The adaptive quality control loop involves adjusting the channel condition thresholds with variable up and down steps based on target quality metrics along with measurements such as error detection results, relative frequencies of visiting each MCS level, and transmitted data rates, wherein the target quality metrics can be a block error rate or bit error rate target criterion. If the target quality metric is a block error rate target criterion, the variable step is determined using a desired MCS error rate based on MCS probabilities, MCS error rates and the block error rate target criterion. If the target quality metric is a bit error rate target criterion, the variable step is determined using a desired MCS error rate based on MCS probabilities, MCS error rates, average rate of bit errors, data rate, and the bit error rate target criterion.

An encoder for use in scalable video coding has a mechanism to perform macroblock mode selection for the enhancement layer pictures. The mechanism includes a distortion estimator for each macroblock that reacts to channel errors such as packet losses or errors in video segments affected by error propagation; a Lagrange multiple selector for selecting a weighting factor according to estimated or signaled channel error rate, and a mode decision module or algorithm to choose the optimal mode based on encoding parameters. The mode decision module is configured to select the coding mode based on a sum of the estimated coding distortion and the estimated coding rate multiplied by the weighting factor.

A linear transformation of parallel space-time transmit diversity encoded streams; also, asymmetrical symbol mapping of parallel streams. Separately or together, these improve error rate performance as well as system throughput. Preferred embodiments include CDMA wireless systems with multiple antennas.

A data communication apparatus determines whether the error type is a burst error or not based on an error occurrence state of the data received from a data transmitting apparatus and transmits error type-basis error information. The data communication apparatus receives the error type-basis error information and sets the redundancy degree of an FEC processing section based on the error rate of the errors other than a burst error.

Dynamic channel estimation thresholds allow for determining optimal threshold values for channel estimation in a layered-modulation wireless communication system. A channel estimation threshold can be used to remove or otherwise filter out channel estimate components that may be significantly influenced by noise. The channel estimation threshold value can be used to generate a refined channel estimate that is used in decoding multiple layers of a layered modulation signal. The channel estimation threshold value can be varied based on the performance of the various signal layer decoders. The adaptive channel estimation threshold provides for decoding a base layer based on an optimal threshold value for the base layer; determining an error rate associated with decoding the base layer; and using an optimal threshold value for an enhancement layer in a channel estimation algorithm if the error rate is lower than a predetermined level.

An AICH control circuit (14) outputs, to an AICH generating Circuit (3), RACH resource information from an RACH resource management circuit (13), SIR information from a finger part (4), error rate information from a decoding part (5), and a call processing control signal. The AICH generating circuit (3) uses AICH information from the RACH resource management circuit (13) and an AICH control signal.

A wireless broadband communications system that can maintain high data rates while taking into account channel interference resulting from operating in shared frequency bands, signal fading resulting from dynamic channel degradation, and signal distortion resulting from compliance with maximum power output regulations. In one mode of operation, the system performs adaptive modulation by transmitting a first signal over a selected channel using a first modulation mode having a level of distortion associated therewith resulting from operating the system at a predetermined maximum power output level. Next, a SINAD level is measured on the first channel. The level of distortion associated with the first modulation mode is then subtracted from the measured SINAD level to obtain a first noise level. In the event the first noise level is less than a noise level required to achieve an acceptable error rate in a next modulation mode, a second signal is transmitted over the selected channel using the next modulation mode.

A wireless communication apparatus performs wireless communication using a plurality of frequency channels. In order to prevent a radio signal from interfering with another wireless communication system, the apparatus includes a unit which detects an error rate of each of the plurality of frequency channels, a unit which determines whether the detected error rate is higher than a specific threshold value, and a unit which suspends use of a frequency channel whose error rate is determined to be higher than the threshold value.

Immediately before transmitting a packet signal, a packet transmission base station (BS1) increases a target ISR of UL DPCH (S12), increases the TPC transmission power transmitted by the DPCH (S13), increases a power balancing reference power, and increases a DL DPCH transmission power (S14). In a mobile station (MS3), during packet reception, only a packet transmission base station (1) controls the UL DPCH transmission power (S15). This improves the reception quality at the base station (1) of HS-DPCCH including ACK / NACK and reduces the error ratio of the ACK / NACK signal.

An inputting unit 10 of a channel bandwidth utilization ratio evaluating server 1 inputs various traffic parameters and transmission parameters. A packet sending-out time computing section 21 obtains a packet sending-out channel time based upon a packet size and the transmission rate. Further, a probability computing section 22 obtains a channel bandwidth utilization ratio based upon the packet sending-out channel time, a cycle time of a packet, and a communication error ratio. Further, the channel bandwidth utilization ratio evaluating server 1 evaluates the obtained channel bandwidth utilization ratio. For example, the channel bandwidth utilization ratio evaluating server 1 determines whether or not receipt of a new call is permitted based upon the obtained channel bandwidth utilization ratio. Further, the channel bandwidth utilization ratio evaluating server 1 determines an optimum control based upon the obtained channel bandwidth utilization ratio.

A multilevel optical receiver can comprise a plurality of comparators that generally correspond with the number of levels in a multilevel data stream. Each comparator can be individually controlled and fed a decision threshold in order to decode a multilevel signal. The multilevel optical receiver can generate a statistical characterization of the received symbols in the form of a marginal cumulative distribution function (CDF) or probability density function (pdf). This characterization can be used to produce a set of ε-support estimates from which conditional pdfs are derived for each of the transmission symbols. These conditional pdfs may then be used to determine decision thresholds for decoding the received signal. The conditional pdfs may further be used to continuously estimate the fidelity or error rate of the received signal without the transmission of a testing sequence. The ε-supports may further be used to automatically control the gain on the receiver.

The invention provides an adaptive frequency hopping spread-spectrum (FHSS) transmission system and method, which efficiently utilizes available transmission bandwidth, whilst providing robustness to jamming techniques in wireless communication systems. The proposed technique operates by transmitting a wide-band signal over multiple, single-carrier, parallel transmission subbands, which may occupy non-contiguous frequency regions. The proposed scheme exhibits significant gain in error rate performance, as compared to a data rate equivalent single-subband system in the presence of signal jamming and / or interference without a reduction in the transmission data rate nor an increase in transmitter power. In addition, the proposed system and method are adaptive and enable more efficient use of the available bandwidth for communicating, thus increasing the overall bandwidth utilization of the system.

Encoding / decoding memory devices and methods thereof may be provided. A memory device according to example embodiments may include a memory cell array and a processor including at least one of a decoder and an encoder. The processor may be configured to adjust a redundant information rate of each channel, where each of the channels is a path of the memory cell array from which data is at least one of stored and read. The redundant information rate may be adjusted by generating at least one codeword based on information from a previous codeword. Therefore, example embodiments may reduce an error rate when data is read from and written to the memory device.

A method and system for the estimation of the effect of packet loss on a viewer's subjective perception of a packet video stream. The method involves estimating a quality metric for every frame in the video stream, accumulating such metrics over time, and transforming the result into a Mean Opinion Score (“MOS”) which represents the viewer's subjective perception of the video stream. The method takes into account various factors such as frame rate, frame types and sizes, decoding algorithms, propagated error rates, and the effect of video content on viewer perception. The method can be used for both encrypted and unencrypted video streams.