6results about "Network synchronisation" patented technology

The present invention discloses a method for high-speed non-coordinated concurrent access in an underwater acoustic Internet of Things, which realizes a time-varying channel against Doppler and strong multipath, and improves the throughput of a time-varying underwater acoustic system while solving conflicts. The method includes: 1. Allocate two ZC sequences with different root indexes to different users, which are used as auxiliary sequences and modulation sequences respectively; 2. Use a sliding correlator to perform cross-correlation operations on the received baseband signal. The preamble consists of three repeated ZC base sequences; when detecting continuously equidistant signals exceeding a threshold, retain the potential peaks and their corresponding root indexes, and determine the earliest peak as the starting position of the preamble, and then determine the starting position of data demodulation for different users according to the preamble length; 3. Demodulate the template signal based on the auxiliary sequence, demodulate the signal to be demodulated based on the modulation sequence, introduce the Pearson correlation coefficient with an adaptive weight to calculate the correlation coefficient between the template signal and the signal to be demodulated, and demodulate the data of the specified user from the superimposed data symbols.

In a wireless communication system, including transmitter entities, digitally controllable scattering (DCS) entities, a receiver entity, and a control entity, the receiver entity can identify, by respectively transmitting or scattering a signal, which of the transmitter entities and which of the DCS entities contributed to a receive signal received at the receiver entity over one or more direct links and / or one or more indirect links. The identification by the receiver entity is based on the use of Zadoff-Chu (ZC) identities determining ZC sequences, where unique ZC identities are used at the transmitter entities for transmitting signals and at the DCS entities for scattering impinging signals.

The application discloses a kind of near-field coherent heart radio frequency sensing method and system based on code division multiple access, comprising: 4-way frequency f synchronous baseband signal is configured, 4-way synchronous chip is configured, synchronous baseband signal is multiplied with corresponding synchronous chip to modulate, and 4-way digital baseband signal is obtained;4-way digital baseband signal is handled to obtain 4-way heart measurement signal;4-way heart measurement signal is respectively transmitted to corresponding antenna by radio frequency transceiver and is emitted;The antenna is respectively arranged in left ventricle, left atrium, right ventricle, right atrium;Antenna receives reflected signal, and is recorded as heart sensing signal;Heart sensing signal is transmitted to radio frequency transceiver, and after processing, the baseband signal containing heart chamber beat information is obtained;The baseband signal containing heart chamber beat information is multiplied with corresponding synchronous chip to demodulate, band-pass filter, and the demodulation signal corresponding to heart chamber beat information is obtained respectively.

The invention relates to the technical field of power line carrier communication optimization. The invention relates to a power line carrier communication optimization method based on synchronous code division multiple access. The method comprises the following steps: S1, acquiring a communication coverage area, performing area division according to the communication coverage area into a branch area, a branch area and a tail end area, setting a data gateway in each area at the same time, and configuring power line carrier and millimeter wave double-link communication in the data gateways; according to the method, three levels of transmission areas are divided in combination with link characteristics, so that the coverage boundary accuracy is improved by more than 40%, the problems of unreasonable area division and poor coverage and link adaptability in the prior art are solved, a foundation is laid for double-link linkage transmission, unique binding of fragments and terminals is realized by adopting 128-bit SCDMA composite coding, a self-adaptive fragmentation strategy is combined, and the transmission efficiency is improved. The interference-free transmission of multiple users and multiple fragments is guaranteed, the flexibility of data transmission is improved, and the transmission requirements of different service types are met.

The present disclosure proposes various entities in a wireless communication system, in particular, transmitter entities, digitally controllable scattering (DCS) entities, a receiver entity, and a control entity. The receiver entity can identify, which of the transmitter entities and which of the DCS entities contributed, by respectively transmitting or scattering a signal, to a receive signal received at the receiver entity over one or more direct links and / or one or more indirect links. The identification by the receiver entity is possible due to the use of Zadoff-Chu (ZC) identities determining ZC sequences, wherein unique ZC identities are used at the transmitter entities for transmitting signals and at the DCS entities for scattering impinging signals.

The present disclosure proposes various entities in a wireless communication system, in particular, a transmitting entity, a digital controllable scattering (DCS) entity, a receiving entity, and a control entity. The receiving entity may identify the transmitting entity and the DCS entity that contribute in received signals received by the receiving entity over one or more direct links and / or one or more indirect links by transmitting or scattering signals, respectively. The identification by the receiving entity is possible due to the use of Zaudoff-Chu (Zadoff-Chu, ZC) identification that determines a ZC sequence, a unique ZC identification is used at the transmitting entity to transmit a signal, and a unique ZC identification is used at the DCS entity to scatter an incident signal.