4results about How to "Long communication distance" patented technology

This invention discloses an underwater acoustic modem based on STM32 and Raspberry Pi, belonging to the field of underwater acoustic communication technology. Compared with previous modems, this invention improves upon the shortcomings of DSP-based modems, which are characterized by high cost, difficult development, and relatively poor system compatibility; and software-defined radio architecture modems, which are characterized by high hardware cost, high power consumption, and unsuitability for deployment in underwater communication networks. Furthermore, most existing modems cannot simultaneously guarantee communication distance and low bit error rate. This invention utilizes a low-power, low-cost STM32 chip and Raspberry Pi as the core board for modem development. With Raspberry Pi as the software core, it offers faster speed, larger memory, and easier development and expansion. The device size is reduced through a self-designed MCU, meeting the requirements of underwater network nodes. It also employs an adaptive autocorrelation threshold algorithm, enabling the demodulator to adapt to various underwater environments during frame synchronization, while achieving longer communication distances and lower bit error rates.

This invention proposes a composite rod-type magneto-electro-mechanical antenna and its fabrication method, belonging to the field of mechanical antenna technology. It solves the problems of low power capacity, weak radiation capability, and short communication distance commonly found in existing magneto-electro-mechanical antennas. It comprises a magnetostrictive layer, two transition layers, two sets of driving layers, and two sets of tail mass blocks. The magnetostrictive layer is located at the center, with the transition layer, driving layer, and tail mass blocks arranged sequentially from the center to both ends on either side. Each driving layer is composed of multiple piezoelectric ceramic rings and multiple electrode sheets stacked alternately. Each tail mass block consists of mass block one, a disc spring, and mass block two connected sequentially. The length of this composite rod-type magneto-electro-mechanical antenna is comparable to that of a traditional three-layer magneto-electro-electric antenna. When the antenna adopts the first-order longitudinal mode, it can operate in the very low frequency band. Depending on different application requirements, the composite rod-type magneto-electro-mechanical antenna of this invention can adopt the second-order longitudinal mode or operate in other frequency bands.

The application discloses a kind of robust fast secret channel construction methods for amplitude using CSS spread spectrum modulation, mainly solve the problems, such as the limited transmission distance and capacity of secret channel in the existing low-power wide-area network environment, steps include: the modulation method design of secret channel;Signal frame structure design and frame detection;The demodulation method design of secret channel;Analysis is carried out to the information loss in the demodulation process of secret signal.The application designs the LoRa physical layer secret channel modulated by amplitude using CSS spread spectrum modulation method, designs the modulation and demodulation method of secret channel, analyzes the information loss in the demodulation process of secret signal, constructs the robust fast secret channel, widens the construction scene of secret channel, and the operation method is simple and clear, has practical value.

The utility model relates to a kind of dog training device with wireless fence and forbidden area blocking function, including remote controller and receiving device set on pet necklace, the remote controller is integrated with ultra-wideband positioning module, wireless control module, button input module, display module and control processing module, can realize forbidden area boundary setting and the switching of three kinds of working mode.The receiving device includes positioning response module, signal receiving module, control execution module and behavior feedback module, can be according to the instruction of remote controller, to pet carries out electric stimulation, vibration or sound prompt etc. behavior feedback, to realize the effective control of pet.The utility model has the advantages of clear structure, high function integration, with accurate positioning, timely response and feedback mode variety, suitable for pet behavior management in multiple scenes.