2923results about How to "Reduce bit error rate" patented technology

An apparatus, system, and method are disclosed for storage space recovery after reaching a read count limit. A read module reads data in a storage division of solid-state storage. A read counter module then increments a read counter corresponding to the storage division. A read counter limit module determines if the read count exceeds a maximum read threshold, and if so, a storage division selection module selects the corresponding storage division for recovery. A data recovery module reads valid data packets from the selected storage division, stores the valid data packets in another storage division of the solid-state storage, and updates a logical index with a new physical address of the valid data.

A fiber optic transmitter comprising a digital driver adapted to adjust the crossing point of a digital base signal, an optical source adapted to receive the digital base signal and produce a frequency modulated optical signal, and an optical spectrum reshaper adapted to convert the frequency modulated optical signal to an amplitude modulated optical signal. A method for transmitting a signal, comprising: adjusting the crossing point of a digital base signal; providing the adjusted signal to an optical source to produce a frequency modulated optical signal; and providing the frequency modulated optical signal to an optical spectrum reshaper to convert the frequency modulated optical signal to an amplitude modulated optical signal.

A bidirectional signal processing method uses parallel transmission of digital transmitted data streams in a multiple input-multiple output system. Related art methods generate high bit error rates mostly in singular transmission channels. For this reason, the rank-adaptive signal processing method provides that the number n_d of active subchannels are varied according to the actual channel behavior in order to effect a robust data transmission even in singular radio channels based on a transmit-side and receive-side channel knowledge and a modification of the data vector by a linear matrix vector multiplication while introducing a factor gamma for limiting the maximum transmit power. The maximum transmit power is then only distributed to the currently activated subchannels so that no transmit power remains unused. Another optimization of the number of subchannels n_d occurs when selecting the modulation and encoding methods. During the optimal rank-adaptation according to the water-filling principle, another power is allocated to each subchannel. Another modulation and encoding method is accordingly selected for each data stream. During the suboptimal rank-adaptation according to the channel inversion principle, all subchannels have the same power whereby enabling the data streams to be modulated and encoded in a common source

An integrated maximum a posteriori equalization and turbo product coding (IMAP-TPC) system for optical fiber communications systems (OFCS) is provided that uses probabilistic characterization of the electrical current in the presence of inter-symbol interference (ISI) and noise to compensate their effects and improve the bit error rate. In the IMAP-TPC system, turbo product code (TPC) decoding is integrated with a symbol-by-symbol maximum a posteriori (MAP) detector. The MAP detector calculates the log-likelihood ratio of a received symbol using the conditional electrical probability density information, and hence obtains a much more accurate reliability measure than the traditional measure used in the TPC decoder.

The invention belongs to the field of domestic security, environmental monitoring wireless alarming system, characterized in that it at least comprises a monitoring host computer, a base station, a GSM/GPRS modem and several intelligent nodes, where the intelligent nodes are used to detect indoor temperature, humidity, fire alarm, gas leakage and illegal invasion and are composed of sensor plate, microcontroller unit, radio frequency communication module and power supply module, the base station and the intelligent nodes intercommunicate any one of the three protocols of sMAC, IEEE 802.15.4 and ZigBee and the base station transmits the sampled data of the intelligent nodes to the monitoring host computer; and the monitoring host computer is installed with monitoring application software, and has defence setting and withdrawing switching button to control the base station, and also has phone number keying-in and modifying function and a fuction fo giving an alarm to users by phone short messages.

The invention is concerned with the data transmission method and the system, it is: the user's terminal or the base station as the sending side, the corresponding base station or the user's terminal as the receiving side, the sending side process code for the information bit in order to get the code block number equal with the biggest resend time, the sending side divides the code block number into at least two groups, and at least the first group includes two code block; sets the transmission time slot of each code block in the group, and sends to the receiving side; the receiving side receives code block and decode, after receiving a group of code block, if the decode is still incorrect, feedbacks once NACK. The invention can reduce the feedback signaling overhead effectively, improve the utilance of the channel resource.

The invention discloses an inspection system and an implementation method for the electrical equipment of an unmanned aerial vehicle photovoltaic power station. The inspection system includes an airborne terminal, a ground terminal, and a wireless communication module. The camera or monitoring equipment collects the image data of the electrical equipment of the photovoltaic power station, and at the same time receives the control commands sent from the ground terminal to the airborne terminal; the ground terminal is set on the ground platform to process the data collected and sent back by the airborne terminal , to control the flight and shooting operations of the unmanned aerial vehicle on the ground; the wireless communication module completes the functions of transmitting flight control instructions, flight status data, and video return data between the airborne terminal and the ground terminal. The inspection system provides real-time high-definition viewing of infrared images and visible light images, which is convenient for timely resolution of faults. The images are analyzed on the ground side through pattern recognition. repair.

The invention relates to a radio remote control address programmable and bi-directional communication digital light control system, comprising a micro processor, a memory, a radio sending and receiving module, a LCD display, a plurality of keys, a photo inductor, a communication interface circuit for DMX512 and DALI and a plurality of system processing software. The invention has the advantages that the functions of on, off, timing and light-adjusting for the a wireless remote control light or a wireless remote control electric appliance are realized; a programmable online radio for user address setup is provided; the emitter can control the receiver as long as the emitter has the same address as the receiver; the communication is bi-directional while the control is unidirectional; the LCD of the emitter displays human-machine conversation and integrates the functions of time, temperature, timing and switch. The invention is suitable for the control and use of radio remote control light and household appliances in families, hotels, restaurants, companies and other locations.

The invention discloses a polarization compensation implementation method of a continuous variable quantum key distribution system. The polarization compensation implementation method comprises the following detailed steps that: a transmitting end transmits signal light and local oscillator light through one optical fiber by adopting a polarization multiplexing manner, and a receiving end separates the signal light and the local oscillator light by a polarization beam splitter, wherein a polarization feedback control method is divided into two stages, to be specific, in the light splitting detection stage, the receiving end for distribution of continuous variable quantum keys separate a part of local oscillator light out and covers the local oscillator light into a DC feedback voltage signal through a conversion circuit; and in the polarization correction stage, the receiving end controls a dynamic polarization controller by a feedback algorithm according to the DC feedback voltage to finish polarization correction. The brand-new polarization feedback control implementation method of the continuous variable quantum key distribution system, provided by the invention, has the advantages of effectively preventing the polarization state of continuous variable quantum signals from being subjected to environment interference in the optical fiber communication process, improving the system stability and promoting the practicability of the continuous variable quantum keys.

An improved acknowledgement (ACK) prioritization scheme is disclosed that provides ACKs with a lower block error rate (BLER) (as opposed to data) over an air interface, provides a separate radio bearer for ACKs, and successively increases the priority of ACKs for each retransmission required. A lower BLER target for ACKs may be achieved by an increase in transmit (Tx) power, additional coding for the radio bearer, or the use of diversity or hybrid automatic repeat request (ARQ) schemes. After packets are identified as either data or an ACK, they are sent to separate Tx buffers over separate radio bearers. Because the ACKs are transmitted over separate bearers and Tx buffers as compared to the data, ACKs are never queued behind the data, and are effectively prioritized as compared to the data. When retransmissions are required for an ACK packet, the scheduling prioritization is increased successively for each ACK retransmission required.

The invention belongs to the technical field of communication, and relates to a backscattering communication modulation method based on orthogonal frequency division multiplexing (OFMD) carriers The modulation method provided by the invention is characterized in that the modulation method is applied to a backscattering communication system comprising a radio frequency source, a reader and a tag, and comprises the following main steps: a radio frequency source transmits an OFDM carrier signal to a tag; the tag receives the OFMD signal, the tag also comprises a backscattering antenna and a radio frequency energy collection module, the radio frequency energy collection module is used for collecting energy of the OFDM signal in a tag environment, and the backscattering antenna is used for sending information bits to the reader; and the reader receives and decodes a backscattering signal from the tag. The modulation method provided by the invention has the beneficial effects that compared with traditional designs, a specified wireless signal does not need to be sent to serve as the carrier, and higher energy efficiency, a lower bit error rate and a higher data rate can be achieved.

The invention discloses a method, network equipment and a system for data transmission, which can be applied to star and tree networks and dual-homing looped networks. The method comprises that: in a downlink direction, a master node transmits a downlink service signal to a slave node in a mode of optical layer broadcast, wherein a continuous optical signal which carries the downlink service signal also comprises an uplink bandwidth map; the slave node and the master node are connected by an OB (Optical Burst optical burst) channel; and the slave node adapts an uplink service signal to different OBUs for performing photoelectric conversion and transmitting a burst optical signal in a burst mode according to the number and serial number of the OBUs distributed to nodes in the uplink bandwidth map transmitted by the master node. The method, equipment and system easily realize burst amplification and high-speed burst receiving so as to better meet the requirements on long distance, large bandwidth and high transmission quality.

An antenna multiplexing system and a method of a smart antenna and a Multiple-Input Multiple-Output antenna are provided, wherein the system includes a MIMO antenna array and a smart antenna array, the smart antenna array includes several groups of antenna array elements in which the distance between neighbor antenna array elements is less than or equal to one half of wavelength, and the smart antenna array comprises at least two groups of antenna array elements with the coherence sufficient for the requirement of the MIMO applications. The method includes: in accordance with the type of the data to be transmitted, determining a transmitting mode and processing the data to be transmitted accordingly, and in accordance with the transmitting mode, controlling the MIMO antenna array or smart antenna array, so as to transmitting the data to the mobile terminal. With the premise that the actual coverage of TD-SCDMA system should be further improved, the requirement of higher user throughout could be met, and the MIMO antenna system could satisfy the requirement of the future system evolution. Both of the applications of the MIMO and the smart antenna could be met with the use of the same antenna feeding system, and the adaptive switching of the MIMO and the smart antenna with respect to the user could be achieved.

The invention relates to a data processor system for space-based measurement and control of a high-speed aircraft. The data processor system comprises a power supply module, an interface module, a control module, an encryption module, a forward processing module and a reverse processing module, wherein the power supply module is used for providing the secondary power source for the other modules; the control module is used for receiving control instructions, and sending the control instructions to the other modules; the encryption module is used for encrypting the reverse data stream and decrypting the forward data stream respectively; the forward processing module is used for receiving the mid-frequency signal, completing the receiving and processing link, recovering forward information, and outputting the forward information to an external device through the interface module; the reverse processing module is used for receiving image data, flight state information and remote measurement information, generating the mid-frequency signal after completing the launching and processing link to output the mid-frequency signal to an external radio frequency front end, and eventually sending the mid-frequency signal to a ground system. The data processor system supports the carrier high-dynamic measurement and control of the aircraft, is large in region coverage, supports multiple users, can realize real-time two-way communication with the aircraft, and has certain interference capability.

The invention provides a method for realizing partner selection and cooperative transmission combining with position information. The method is to obtain the position information of each node by directly using a cooperative positioning technology of a cooperative communication system and provide a partner selection strategy according to the large-scale fading condition of information transmission: an information source firstly calculates a distance between the information source and each candidate trunk node; the information source adds the distance between the information source and each trunk node and the distance between each trunk node and a base station by combining the obtained position information of each candidate trunk node and the distance information between the candidate trunk node and the base station; the information source selects a trunk node with the minimum total distance value of a trunk information channel as a cooperative partner of the information source to help the information source transmit information, after the total distance value of the trunk information channel of each trunk node is known, thereby realizing gain of space diversity reception, reducing path loss, and achieving the aims of reducing the bit error probability during transmitting, improving the signal quality and expanding the network coverage.

A computer readable medium, a system and a method for flash memory device parameter optimization, the method may include: receiving or generating an estimate of a wear level of at least one group of flash memory cells of the flash memory device, and finding erase parameters and programming parameters to be applied on one or more groups of flash memory cells of the flash memory device in response to estimate of the wear level.

The invention provides a neural network equalization method used for an indoor visible light communication system, and belongs to the visible light wireless communication technology field. The method includes the steps: utilizing a ceiling bounce model to calculate a VLC channel impulse response, carrying out photoelectric conversion for a visible light power signal received by a receiving end, and sending a sequence to a neutral network channel equalizer after amplification sampling; utilizing a heredity algorithm to optimize initialization weights and thresholds among neurons, establishing a neural network for training, and minimizing an error function; and judging an output, restoring the sent sequence, and finally achieving an equalization purpose. According to the scheme, interference among codes is obvious minimized, an error rate is reduced, the communication quality is further improved, a transmission rate that the system can reach is increased, the training time is shortened, and the system complexity is reduced.

Multiple RFID integrated circuit microradio chips are located at the feed point of an RFID tag antenna for greater reliability, elimination of testing and to take advantage of coherent microradio operation for increased gain and power, better signal-to-noise ratios, improved range and low bit error rates.

A method and system for communicating a clock signal over an optical link includes receiving a multimodulated optical information signal including non-intensity modulation for a data signal and intensity modulation for a clock signal. The clock signal is recovered based on the intensity modulation of the multimodulated optical information signal. The non-intensity modulation for the data signal is converted to intensity modulation for the data signal. The data signal is recovered from the intensity modulation for the data signal using the clock signal.

Tap coefficients for fractionally-spaced equalizers are updated iteratively using error statistics from an input bit stream and an output bit stream, such as from a forward error correction circuit. The process continues until the errors converge to a sufficiently small number. Knowledge of the error patterns are used apriori to adaptively change the tap coefficients in a feedforward filter.

A dual mode clock and data recovery (CDR) system is disclosed. A fast locking, oversampling CDR acquisition module can begin the process to quickly create a data acquisition clock signal in start up data acquisition conditions. When at least some data can be extracted from the incoming data stream, the DRR system can indicate such stability and switch to accept control from a low power CDR maintenance module. The low power CDR maintenance module can then fine tune and maintain the timing of the data acquisition signal. If the quality of the data lock under CDR maintenance module control degrades to a sufficient degree, the high power CDR acquisition module can be re-enables and re-assert control from the low power module until such time as the lock quality is again sufficient for the low power module to be used.

In one embodiment, an optical transmission system transmits data using a format according to which a data frame has two or more pilot-symbol blocks, each having a guard interval, and two or more payload-symbol blocks that are concatenated without a guard interval between them. The use of guard intervals in the pilot-symbol blocks helps the synchronization and channel-estimation procedures performed at a receiver of the optical transmission system to be robust in the presence of certain transmission impairments. The absence of guard intervals in the payload-symbol blocks helps to minimize the transmission overhead and thus achieve relatively high payload-data throughput. Pilot-symbol blocks have a structure that enables the receiver to determine channel-response characteristics for each data frame and then apply appropriate channel-response-compensation procedures to signals corresponding to the payload-symbol blocks of the frame to recover, with a relatively low bit-error rate, the data encoded in those signals.

A CTCS2-class train control system based on wireless locomotive signals is a pint-to-point system for transmitting the train control information via passive responder, regional rail circuit and wireless channel. It is composed of the locomotive carried equipment consisting of ATP device and wireless signaling device, and the ground equipment consisting of wireless signaling device, responder, rail circuit ZPW2000, interface for computer or electric centralizing linkage 6502, and interface for train scheduling and command system or scheduling centralizing system (TDCS or CTC).