52results about How to "Reduce packet error rate" patented technology

The invention discloses an internet protocol (IP) data compression transmission method applicable to a satellite channel and relates to the technical field of a satellite communication network based on a transmission control protocol (TCP)/ IP. IP data packages are compressed to be transmitted on a satellite link. The IP data compression transmission method aims at improving use ratio of satellite channel resources and service access quantity, reducing transmission delay of the IP data packages on the satellite link and enabling the IP data packages to be efficiently and robustly transmitted on the satellite link with high error code, long transmission delay and limited bandwidth resources by compressing the IP data packages to remove redundant data. The method is also applicable to ground cellular mobile communication links and wired and wireless links which are provided with high error code and long transmission delay.

A wireless broadband communication system that operates with high efficiency and reduced latency in long range point-to-point and point-to-multipoint applications. The system includes multiple transceivers and multiple antennas for transmitting and receiving wireless signals using TDD techniques over multiple channels, which include a control channel for setting both the size of the transmit bursts and the modulation threshold level. By determining the size of the transmit bursts for a subsequent data transmission based upon the number of filler packets detected in a specified number of previously received bursts, and adjusting the modulation threshold level for the subsequent transmission based upon the transmit burst size, the system provides increased data throughput, while maintaining the packet error rate at an acceptable level. As the throughput requirements of the system are relaxed, the modulation threshold levels can be adjusted to provide reduced packet error rates.

The invention discloses a carrier phase synchronization method and device for a non-coherent demodulation circuit. An all-digital implementation mode is adopted for the method and the device, and two working modes, namely. a phase acquisition mode and a phase tracking mode, are adopted. The method comprises the following steps: in a phase acquisition stage in a preamble period, estimating carrier frequency offset by delay-related calculation on a preamble, estimating an initial phase by utilizing a frequency offset estimation result and a known preamble sequence, and performing frequency and phase compensation calculation on received data; after the preamble period, starting dispreading the data, and starting a phase tracking stage; and in the phase tracking stage, performing correlation calculation by utilizing spreading code data corresponding to demodulated symbols and the received data, estimating a residual phase difference of each symbol, and performing phase compensation calculation on the received data. The method and the device are used for the carrier phase synchronization of a non-coherent demodulation digital baseband design, and the carrier phase synchronization can be accurately implemented under the condition of low signal to noise ratio.

Systems and methods directed towards improving reliability for wireless networks. Selective polling techniques are utilized to selectively poll stations within a wireless network in order to ensure that a station failing to properly transmit data is given an opportunity to rectify the transmission failure. The selective polling techniques can be applied to any polling-based system, thus maintaining backwards compatibility with legacy systems.

The invention provides a satellite mobile communication system, method and device supporting simplex data collection service. The satellite mobile communication system adopts a multiple-access technology. The service is backwards compatible with a data collection system. The satellite mobile communication system and the data collection system adopt the same frequency band. The data collection system supports two operation modes: data collection independent operation and cooperative operation with the satellite mobile communication system. The independent operation mode is applicable to the occasion having only uplink services. The invention also provides a corresponding method and a receiver device. According to the invention, the spectrum resource is saved, the implementation mode is flexible and simple, a constellation system is enabled to realize that the data collection service is expanded to the mobile communication service with global coverage in the same frequency band.

The invention discloses a communication method used in a multiple-input and multiple-output system, comprising transmitting antenna combination chosen by the receiving end according to the communication channel conditions, the receiving end sending the transmitting antenna combination information chosen to the sending end and the sending end according to the transmitting antenna combination information received to send signals to the receiving end via the transmitting antenna combination chosen. The invention also discloses a communication system used in the multiple-input and multiple-output system, comprising a sending end and a receiving end. According to the invention, because the receiving end chooses the transmitting antenna that adopts the principle of channel capacity maximization and sends the transmitting antenna chosen to the sending end, the sending end sending signals to the receiving end adopting the transmitting antenna chosen can reach higher transmitting efficiency, or arrives at a lower packet error rate in the receiving end.

A method for confirming downlink interval and uplink interval in Wimax system includes setting uplink sequence table and downlink sequence table and dynamically selecting error correction code and modulation mode as well as coding rate according to current S-N ratio and data flow rate.

The invention relates to a method and a device for Zigbee technology-based FlexRay bus test and optimization. The device comprises a PC, a Zigbee module and a FlexRay bus test node, wherein the FlexRay bus test node comprises a Zigbee module, a programmable clock chip, a digital potentiometer and an MCU microprocessor. According to the method and the device disclosed by the invention, the state of a FlexRay bus is detected and controlled in real time by applying a Zigbee technology, the programmable clock chip and the digital potentiometer are utilized for adjusting a transmission frequency and a matching impedance, reducing the packet error rate of the bus, improving the transmission quality and the reliability of the bus, and increasing the transmission efficiency of the bus; the method and the device are capable of realizing automatic assessment, test and parameter optimization for the performances of the FlexRay bus, and capable of giving the optimal impedance matching reference value of each node, thus improving the reliability of the data transmission of the FlexRay bus.

The invention discloses a retransmitting linear precoding processing method for a multi-input multi-output system. The method is characterized by comprising the following steps of: distributing power to sub-channels of which the signal to interference and noise ratio is smaller than a decoding threshold against each sub-channel pairing matrix in the multi-codon supported MIMO system retransmission precoding processing process; performing power distribution on residual power according to a target of minimizing the packet error rate to calculate the minimum packet error rate relative to the sub-channel pairing matrix; and traversing all sub-channel pairing matrixes, selecting the sub-channel pairing matrix corresponding to the minimum value in the minimum packet error rate as an optimal sub-channel pairing matrix, and distributing power to each sub-channel according to the optimal sub-channel pairing matrix. By adopting the method, the packet error rate lower than that of the traditional method can be achieved by reasonably pairing sub-channels and distributing power according to the adaptive modulation coding level selected by each codon.

The embodiments of the present invention disclose an RTS frame transmission rate adjustment method, an RTS frame transmission rate adjustment device, an apparatus and a storage medium. The method includes the following steps that: after the state of an RTS/CTS mechanism is set to be startup, and before a first RTS frame corresponding to current data to be sent is sent, a RTS packet error rate corresponding to a current period is determined according to the RTS packet error rate corresponding to a previous period; and the initial transmission rate of an RTS frame corresponding to the current period is determined according to the RTS packet error rate corresponding to the current period and the initial transmission rate of the RTS frame corresponding to the previous period. With the RTS frame transmission rate adjustment method, the RTS frame transmission rate adjustment device, the apparatus and the storage medium provided by the technical schemes of the embodiments of the invention adopted, the initial transmission rate of the RTS frame corresponding to the period can be adaptively adjusted according to the current interference condition of the transmission path of wireless data, and therefore, the packet error rate of the RTS can be reduced to a certain extent, and the transmission overhead of the RTS/CTS mechanism can be reduced.

The invention relates to a partitioning method for an observation space in the BPSK demodulating process. The observation space is a complex plane displayed by a BPSK signal constellation picture. The partitioning method comprises the following steps of: S1, uniformly partitioning the integral observation space into (with reference to the specification) sector observation domains according to an anticlockwise direction, wherein (with reference to the specification) is a random finite positive even number and is used for representing the number of the observation domains; S2, enabling an angular bisector of a first observation domain to be coincided with positive half axis of a real axis; and S3, determining an angle value of the angular bisector of each observation domain as an observation quantity of the observation domain. Application of the partitioning method for the observation space in the BPSK demodulating process is applicable to an incoherent BPSK receiver in an IEEE802.15.4 protocol. The invention provides the partitioning method for the observation space in the BPSK demodulating process and the application thereof to the IEEE802.15.4 protocol. By carrying out reasonable partitioning on the observation space, reliability of the information transmission process is improved; the more the partitioned observation domains are, the higher the reliability is; and by reasonably selecting the number of the observation domains, low-energy-consumption signal transmission can also be implemented.

The invention relates to an antenna arrangement for vehicle-to-vehicle communication, wherein at least two antenna transmitters (12, 13), each having a unidirectional directional diagram, are positioned in such a manner that a combination of the unidirectional directional diagrams of the antenna transmitters generates a largely omnidirectional directional diagram by means of a method for transmitting and/or receiving.

The invention discloses a method for supporting high-speed mobility in a wireless communication system, comprising the following steps of arranging the circular prefixal length for the sub-frame moving at high speed and arranging the region information of the sub-frame (moving at high speed) of the uplink and downlink at the base station; wherein the region information is used for specifying the position of the sub-frame moving at high speed in the frame structure; the base station broadcast sends the region information of the sub-frame moving at high speed and the length of the circular prefix; each mobile station of the base station receives and memorizes the region information in the broadcast control message and the length of the circular prefix; the base station deploys the data of the user moving at high speed into the region information of the sub-frame moving at high speed; and the mobile station moving at high speed sends or receives the data in the sub-frame (moving at high speed) of the uplink and downlink through the arranged length of the circular prefix. The method arranges longer circular prefix in the region of the sub-frame moving at high speed and greatly reduces the effects of the carrier wave interference at low complexity.

The invention relates to a bit error correction method based on channel quality assessment. After a received data frame is input to a channel quality error correction system, the system checks the received data frame to judge whether the received data is correct; the data frame is output directly if the received data is correct, and if the received data frame does not pass checking, the system uses a channel quality sequence to find out data bits which are most likely to be wrong, inverse operation is carried out to form a new received data frame, the channel quality error correction system checks the new received data frame, and if new received data frame does not pass checking, the frame of data cannot be repaired and can only be discarded; and if the received data frame passes checking, the received data frame is recovered. By using the method, the most likely wrong receiving bits can be found out, the wrong receiving bits can be checked one by one or through group inverse operation, and more data frames can be repaired. The beneficial effects are as follows: on the premise of not increasing the channel overhead and under a given communication system, the sensitivity of a receiver is improved, the packet error rate is lowered, the quality of communication is improved, and the cost of system optimization is reduced.

The invention provides a power control method, system and device based on a communication network and a storage medium, and the method comprises the steps: obtaining the transmitting signal intensityand/or a power adjustment signal of a central node, wherein the power adjustment signal comprises a power adjustment step length obtained based on the packet error rate of equipment; and obtaining thetransmitting power of the equipment based on the transmitting signal strength and/or the power adjusting signal of the central node. According to the method provided by the invention, an open-loop and closed-loop power control method is introduced on the basis of a communication network, so that the power is further reduced, the purpose of saving more power is achieved, and the packet error rateof data communication can be effectively reduced.

The invention discloses a MIMO mode switching control method and device. The MIMO mode switching control method comprises the following steps: confirming the inner loop spectrum efficiency of at least two MIMO modes to be selected according to the CQI reported by a terminal; updating the outer loop spectrum efficiency of the at least two MIMO modes to be selected at the moment that the terminal is scheduled to end; and selecting the MIMO mode with the largest sum of the inner loop spectrum efficiency and the outer loop spectrum efficiency in the at least two MIMO modes to be selected as the current scheduling MIMO mode at the beginning of the scheduling. According to the MIMO mode switching control method, the spectrum updating of the outer loop spectrum efficiency is related to the service type and the size of the service traffic of the terminal, the switching time of the MIMO modes is dynamic and changeable, therefore, the time delay can be reduced, the timeliness of the mode switching can be improved, and the packet error rate while mode switching can be reduced; therefore, the service stability of the mode switching is improved, and the call drop rate in a cell is reduced.

The invention discloses a packet loss processing method in ARQ feedback communication systems which is designed to solve the problem that the prior art cannot meet the Quality of Service (QoS) of systems. The packet loss processing method in ARQ feedback communication systems includes that when queues achieve threshold values and new data arrive, state information of all data packets in the queues is read, the QoS state of each of the data packets is obtained, and lost data packets are confirmed according to the QoS state of each of the data packets. The QoS state comprises ARQ states, data packet transmission times, data packet error rates and /or data packet transmission delay of data packets, and the ARQ states represent whether data packets which are sent but receive no acknowledgment character or negative acknowledge (ACK/MAK) feedbacks exist. The packet loss processing method in ARQ feedback communication systems has the advantages that packet error rates are low, packet error rates of systems are effectively reduced, the data packet transmission delay can be reduced, and thereby the QoS of the systems can be well satisfied.

The invention discloses a WLAN (Wireless Local Area Network) system aggregation retransmission method. The method comprises the following steps: confirming lost sub-frames and a lost number n of aggregation transmission of the WLAN system; judging whether the loss number n is greater than a preset threshold N or not; wherein N is greater than 0 and less than Nmax/2, and Nmax is the maximum numberof aggregation subframes allowed to be contained in one aggregation frame; if not, copying the lost number n for M times to obtain M*n copied subframes; wherein n+M*n is less than or equal to Nmax; and aggregating and retransmitting the M*n copied sub-frames and the lost sub-frames together. The success rate of retransmission can be improved, so that the throughput efficiency of a WLAN system is improved.