68results about How to "Improve error performance" patented technology

A multi-level encoded signal is encoded according to at least an upper-level code and a lower-level code. In a receiver, a modified type of a multistage decoder is deployed. The upper-level code is decoded to produce a sequence of tentative upper-level coding decisions independently of the lower-level code. The lower-level code is next decoded in such a way that the decoding is conditioned upon at least one of the tentative upper-level decisions. The lower-level decoder thereby produces a sequence of lower-level decisions. The upper-level code is then decoded a second time, this time conditioned upon at least one of the lower-level decisions, to produce a second, more reliable sequence of upper-level coding decisions. The lower-level decision sequence and the second upper-level decision sequence are delivered from the decoder as output sequences.

An orthogonal frequency division multiplexing (OFDM) communication system and method for improving frequency utilization efficiency. In the system, a Reed-Solomon encoder codes input information data, and outputs a Reed-Solomon block comprised of a second number of Reed-Solomon symbols each comprised of a first number of Reed-Solomon symbol elements. An interleaver receives the Reed-Solomon block, and disperses the Reed-Solomon symbol elements existing in a specified one Reed-Solomon symbol within the received Reed-Solomon block in the same sub-channel positions in a fourth number of sub-channels of each of a third number of consecutive OFDM symbols.

An error correction circuit capable of detecting burst errors included in a data signal with reliability. The error correction circuit comprises a reading unit, a first estimation unit, a second estimation unit, and a correction unit. The reading unit reads the data signal. The first estimation unit estimates error locations based on BIS code included in the data signal, and stores the locations into an error location storing unit. The second estimation unit estimates error locations based on characteristics of bit strings adjoining the BIS code, and stores the locations into the error location storing unit. The correction unit identifies erasure locations based on the error locations stored in the error location storing unit, and performs erasure correction on the erasure locations identified. Since the error locations are estimated based on the BIS code and the characteristics of the bit strings adjoining the BIS code as well, it is possible to detect burst errors without fail.

A concatenated coded modulation communication system and method combines Trellis Coded Modulation with non-Gray code constellation mapping, interleaving, and non-binary Low Density Parity Check coded channel modulation with Gray code constellation mapping to improve error performance.

This present invention relates to a device for the measurement of the amount of oxygen in a gas mixture, or other gas with significantly different magnetic susceptibility than the background gas mixture, by the use of a suspended test body in a magnetic field that experiences force due to the magnetic susceptibility of the measurand gas. In order to enable a fast time response for the system with a change in oxygen concentration, a flow regime is presented which allows a fast sweep of the measurement volume combined with adjustable, balanced pressure drops via a flow balancing element (or elements) within the flow channels to independently minimise flow related uncertainties.

An error correction circuit capable of detecting burst errors included in a data signal with reliability. The error correction circuit comprises a reading unit, a first estimation unit, a second estimation unit, and a correction unit. The reading unit reads the data signal. The first estimation unit estimates error locations based on BIS code included in the data signal, and stores the locations into an error location storing unit. The second estimation unit estimates error locations based on characteristics of bit strings adjoining the BIS code, and stores the locations into the error location storing unit. The correction unit identifies erasure locations based on the error locations stored in the error location storing unit, and performs erasure correction on the erasure locations identified. Since the error locations are estimated based on the BIS code and the characteristics of the bit strings adjoining the BIS code as well, it is possible to detect burst errors without fail.

The invention discloses an implementation method of a cooperative transmission mechanism based on feedback information. In order to enable a source and a relay in a cooperative communication system to perform better-informed information transmission operation, and to prevent unnecessary information transmitting so as not to waste resources, a target terminal feeds back 2bits information to represent three receiving states, including success, half success and failure, of signals received by a direct transmitting link at the time slot 1, and the source and the relay decide the operation at the next time slot according to the fed back information; moreover, the relay node also can select different relay transfer protocols according to whether the relay node demodulates data successfully or not. According to the invention, compared with a classic cooperative transmission mechanism, the cooperative transmission mechanism provided by the invention has the advantages that on the premise of only needing additional expenditure of 2bits, when the channel variance of the direct transmitting link is only half of that of a relay link, the spectrum efficiency also can respectively reach 120% and 133% of classical AF cooperative transmission and classical DF cooperative transmission, so that intrinsic defects of cooperative transmission are overcome, the spectrum efficiency of cooperative transmission is improved, and the error performance of cooperative transmission is also improved.

Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, wherein the decoder comprises:a processing unit (307) configured to determine at least one candidate set of division parameters and to perform a division of said vector of information symbols into a set of sub-vectors in association with each candidate set of division parameters, each pair of sub-vectors being associated with a division metric;a selection unit (309) configured to select one of said candidate sets of division parameters according to a selection criterion depending on said division metric; anda decoding unit (311) configured to determine at least one estimate of each sub-vector associated with said selected set of division parameters by applying a symbol estimation algorithm,wherein the decoder is configured to determine at least one estimate of the vector of information symbols from said at least one estimate of each sub-vector of information symbols.