33results about How to "Overcoming multipath interference" patented technology

The invention discloses infrared wireless network equipment applied in a satellite capsule. The infrared wireless network equipment applied in the satellite capsule comprises a satellite host computer and satellite-borne electronic equipment, and further comprises an infrared wireless access point and an infrared wireless terminal. The infrared wireless access point is connected with the satellite host computer, and the infrared wireless terminal is connected with the satellite-borne electronic equipment. The infrared wireless terminal comprises a wired interface module A, an infrared optical antenna A, a slave control module and an infrared control module A. The infrared wireless access point comprises a wired interface module B, an infrared optical antenna B, a host control module and an infrared control module B. According to the infrared wireless network equipment, an infrared wireless optical communication way replaces a traditional satellite bus communication way, traditional communication cables among satellite-borne electronic equipment is eliminated, interconnection among electronic equipment inside a satellite is achieved, complexity of connection through the traditional cables is avoided, electromagnetic interference of wireless radio frequency communication is avoided, and the weight of the satellite is lightened effectively.

The invention aims to provide a remote underwater sound communication method and belongs to the technical field of underwater sound communication. The method is based on demodulation and decoding combined iterative detection of differential encoding. A transmitter resists multi-path interference by using spread spectrum communication, the problem of phase jump and loop cycle skipping is solved by using differential modulation quadrature differential phase shift keying with high frequency spectrum utilization rate, and the transmitter adopts demodulation and decoding combined iterative technology to eliminate inter-code interference. The method has the beneficial effects that 1) the error bit rate performance of a remote underwater sound communication system is improved by the demodulation and decoding combined iterative technology; 2) the technical requirement on a non-linear amplifier is reduced by differential modulation, and differential modulation has engineering feasibility; and 3) the multi-path interference of a remote underwater sound channel is overcome by spread spectrum communication.

The invention discloses a multi-mode mine mobile communication system which comprises a control unit, a tree structure passive optical network, a downhole explosion-proof MIMO base station, a downhole explosion-proof SISO base station, a distributed MIMO antenna and a downhole mobile terminal. Multiple modes are dynamically adopted for the system in operation, wherein in the SISO mode, SISO signals are processed through the system by means of a communication gateway of the distributed MIMO antenna and a far-end antenna unit; in the MIMO mode, MIMO output signals are processed through the system by means of the communication gateway of the distributed MIMO antenna and a far-end antenna unit group; in the mixed mode, the SISO signals and the MIMO output signals are processed through the system by means of the communication gateway of the distributed MIMO antenna and antenna unit groups. The system is simple in structure, flexible in deployment, large in the channel capacity, high in anti-jamming capability, wide in network coverage area, capable of overcoming near-far effects, eliminating communication dead zones and meeting the requirements for mining specific operating environments and security and applicable to underground coal mine mobile communication and mobile monitoring.

The invention discloses a frequency hopping pulse bit encoding underwater acoustic communication method based on linear frequency modulation signals. The method comprises the steps of utilizing the characteristic that time slots are not overlapped in underwater multipath interference, adopting modulation combination of frequency modulation encoding and pulse bit encoding to conduct modulation on information, increasing the number of the time slots of each frame by increasing the quantity of frequency hopping to improve the time length of each frame, enabling the delay spread of most multipath signals to be smaller than the duration time of each frame, and utilizing a filter for extracting main path signals from a frequency domain at a receiving terminal. According to the frequency hopping pulse bit encoding underwater acoustic communication method based on the linear frequency modulation signals, on the premise that the multipath interference resistance performance is ensured, devices of a transmitting terminal and the receiving terminal are simplified, the power required by transmission is reduced, the speed of data transmission is increased, and the defects that a traditional underwater acoustic communication technology is complex in device, large in power consumption, large in multipath interference on information, slow in transmitting speed and the like are overcome.