334 results about "Word error rate" patented technology

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.

An error rate select circuit activated in an information sustaining mode is provided, wherein a plurality of pieces of data are read from a dynamic memory circuit and inspection bits which are used to detect an error existing in the pieces of data are generated. If no error is detected, a first predetermined value is added to a total value. If an error is detected, a second predetermined value greater than the first predetermined value is subtracted from the total value. If the total value exceeds a first set value, a refresh period is lengthened by a predetermined time increment. If the total value becomes smaller than a second set value, the refresh period is shortened by the predetermined time increment.

Low-Density Parity-Check (LDPC) codes offer error correction at rates approaching the link channel capacity and reliable and efficient information transfer over bandwidth or return-channel constrained links with data-corrupting noise present. They also offer performance approaching channel capacity exponentially fast in terms of the code length, linear processing complexity, and parallelism that scales with code length. They also offer challenges relating to decoding complexity and error floors limiting achievable bit-error rates. Accordingly encoders with reduced complexity, reduced power consumption and improved performance are disclosed with various improvements including simplifying communications linking multiple processing nodes by passing messages where pulse widths are modulated with the corresponding message magnitude, delaying a check operation in dependence upon variable node states, running the decoder multiple times with different random number generator seeds for a constant channel value set, and employing a second decoder with a randomizing component when the attempt with the first decoder fails.

De novo synthesized large libraries of nucleic acids are provided herein with low error rates. Further, devices for the manufacturing of high-quality building blocks, such as oligonucleotides, are described herein. Longer nucleic acids can be synthesized in parallel using microfluidic assemblies. Further, methods herein allow for the fast construction of large libraries of long, high-quality genes. Devices for the manufacturing of large libraries of long and high-quality nucleic acids are further described herein.

A method and apparatus for channel coding useful for recording channel and other communications applications. The proposed channel coding method is actualized via structured set partition (SSP) in conjunction with multilevel coding (MLC) and offers performance gains over conventional coding schemes with comparable complexity at the bit-error rate (BER) level as well as the sector failure rate (SFR) level.

Alternate methods, devices and systems are presented for providing service providers and / or end users of mobile stations to monitor and / or report regions with high error rates and / or dead zones. A protocol is provided such as to yield the error occurrence, error rate and / or the address of the end user. In some embodiments it also contains location information and time of day information. This information may be collected from the G.P.S., and / or all or a portion of users when there is a significant transmission difficulty and / or an abundance of errors. The collected data forms a database which is analyzed to generate coverage maps. This may include the dynamic aspects of the mobile network. In another aspect of this invention, each mobile station periodically compares its current location with the data base. The results of this comparison enables the mobile unit to anticipate connection problems. In still another aspect of the invention, the comparison is performed by the service provider which notifies the end user.

An error logging and analysis system is used to detect a type of error condition, assign a numeric value corresponding to the severity of the error condition, record the time of the error condition, and determine the frequency between subsequent error conditions of the same type. A weighted error rate is generated as a function of the severity of the initial error condition, the frequency of subsequent error conditions, and a percentage of any preceding weighted error rates. These weighted error rates are compared to a predetermined threshold to determine if the error condition is statistically significant.

Methods and apparatus are provided for sequential authentication of a user that employ one or mole error rates characterizing each security challenge. According to one aspect of the invention, a user is challenged with at least one knowledge challenge to obtain an intermediate authentication result; and the user challenges continue until a cumulative authentication result satisfies one or more criteria. The intermediate authentication result is based, for example, on one or more of false accept and false reject error probabilities for each knowledge challenge. A false accept error probability describes a probability of a different user answering the knowledge challenge correctly. A false reject error probability describes a probability of a genuine user not answering the knowledge challenge correctly. The false accept and false reject error probabilities can be adapted based on field data or known information about a given challenge.

Data communication between two devices (11, 12) over the public powerline network (13) uses a multi carrier technology wherein a communication channel is divided into a plurality of subchannels by frequency division multiplexing. A partial power as part of the total transmission power and a partial rate as a fraction of the total data rate are assigned to each subchannel as follows:Initially, the same partial power is assigned to each subchannel and the S / N ratio of each subchannel is obtained. Starting with the subchannel of the lowest S / N ratio and proceeding to that of the highest S / N ratio, the following steps are performed for each subchannel:Firstly, the partial rate is assigned in accordance with the respective S / N ratio such as to result in a predetermined transmission error rate. The assigned partial rate is then quantised to an integral value. If the quantising corresponds to a rounding down, the initially assigned partial power is reduced such that the transmission error rate remains the same as before quantisation. Further, the partial power of other subchannels with higher S / N ratio is increased such that the sum of all partial powers remains constant. Eventually, the increased S / N ratio resulting from increasing the partial power for these subchannels is calculated so that, when the present steps are conducted for them, an optimum partial rate can be assigned to them.This method maximises the total data rate of the entire communication channel while the error rate of each subchannel and the sum of all partial powers remain constant.

In an optical communication system, a train of optical pulses is transmitted such that each pulse carries a set of multiplexed channels. In a receiver, the error rate for each channel is monitored and a subset of channels having the most favorable rate is selected to carry a first data stream. The remaining channels carry a second data stream. Error rate performance is determined on the basis of error detecting codes carried by the channels in the first and second data streams.

A computing device configured for wireless communication may effectively control adaptation to channel conditions. The device may be configured to identify and classify conditions impacting performance of a channel so that appropriate adaptations may be made. Interference may be detected by correlating received signal strength and packet errors. High received signal strength correlated to a high packet error rate may signify presence of a source of interference. Once a source of interference is detected, other criteria may be used to determine the nature of the interference so that an adaptation that is minimally disruptive of applications can be selected. Additionally, channel degradation may be predicted by monitoring trends in error rates, including Forward Error Correction rates, and adaptation may be used before packet error rates exceed an unacceptable level.