6results about How to "Compensation Distortion" patented technology

The invention provides an OFDM signal receiving and processing system and method suitable for an NAVDAT system. According to the method, the characteristics that NAVDAT system signals have synchronous headers, pilot frequencies and the like are fully considered, firstly, the synchronous headers are used for carrying out correlation operation on received data to search a frame starting point, and a signal frame to be demodulated and decoded is obtained in combination with a constant false alarm detection algorithm; and subsequently, carrying out symbol synchronization to determine the FFT window position. Secondly, in combination with a discrete pilot signal, estimating an integral multiple frequency offset error, namely coarse synchronization, and further realizing estimation of a decimal multiple frequency offset error, namely fine synchronization, so as to realize frequency synchronization. And then, channel estimation is carried out by using the pilot signal and adopting a least square method to obtain the channel frequency response of the pilot, the frequency response of the complete signal is obtained through interpolation, and the rough estimation result is further processed through the designed RCAFCN network to obtain accurate channel estimation, so that the original OFDM signal is recovered. And finally, extracting a data part in the OFDM signal according to a frame structure, realizing soft demodulation through a log-likelihood ratio mode, decoding data of a signaling part by using a polarization code, and decoding data of a service part by using a low-density parity check code, thereby realizing complete demodulation and decoding. The method provided by the invention can effectively reduce inter-symbol interference and inter-carrier interference existing in OFDM signals, compensate channel distortion, reduce noise influence, improve decoding precision, improve communication quality, realize optimization of NAVDAT system baseband processing, and guarantee sailing safety of ships on the sea by combining with an existing marine broadcast system.

The invention relates to the technical field of audio processing, and discloses a wireless audio data transmission and reading method and audio playing equipment, and the method comprises the steps: carrying out the signal processing of an input original audio signal, obtaining digital audio data, and building a waveform equation; performing parameter optimization to obtain an optimal waveform equation parameter; creating a signal processor and processing to obtain an optimized audio signal; performing data division to obtain a plurality of audio data packets, and solving the transmission optimization model to obtain a transmission scheduling scheme; performing coding processing to obtain a coded audio stream, and performing multi-layer mapping to obtain a multi-layer OFDM (Orthogonal Frequency Division Multiplexing) symbol; the method comprises the following steps: receiving the audio data, performing signal reconstruction processing to obtain a receiving end signal, decoding the receiving end signal to obtain decoded audio data, and recombining the decoded audio data to obtain a reconstructed digital audio signal, thereby improving the wireless audio data transmission and reading performance.

The application is suitable for the field of automation control technology, and provides a machining device and a control method, device and storage medium thereof. The machining device comprises a machine tool, a machining head arranged on the machine tool, and a height sensor arranged on the machining head. The control method comprises: periodically acquiring an actual position change of the machining head and a height change collected by the height sensor; determining a periodic signal decay rate according to the actual position change and the height change; determining a grade corresponding to the periodic signal decay rate; if the grade corresponding to the periodic signal decay rate is a correction grade, determining a correction target height corresponding to the correction grade as a height to which the machining head is about to move according to the correction grade; and moving the machining head according to the correction target height. The control method provided by the embodiment of the application can improve the machining precision and stability of the machining device at the edge or corner point of a workpiece.

A distortion compensation device (2) is configured to comprise: an amplification target signal acquisition unit (21) that acquires an amplification target signal that is a signal to be subjected to power amplification by a power amplifier (4); and an operation state signal acquisition unit (22) that acquires an operation state signal indicating the operation state of the power amplifier (4). Furthermore, the distortion compensation device (2) is provided with a distortion compensation unit (25) that estimates, on the basis of the signal to be amplified acquired by the signal to be amplified acquisition unit (21) and the operation status signal acquired by the operation status signal acquisition unit (22), a signal in which distortion has been imparted to the signal to be amplified acquired by the signal to be amplified acquisition unit (21). The predistorted signal is output to the power amplifier (4) as a predistorted signal for compensating for distortion occurring in the signal to be amplified after power amplification by the power amplifier (4).

This invention relates to the field of optical lens technology, and more particularly to an optical system for a large-aperture full-frame fixed-focus lens. It includes a first objective lens group, a second objective lens group, and a third objective lens group arranged sequentially from the object side to the image side along the optical axis. The third objective lens group includes an aperture stop. During focusing, the second objective lens group moves along the optical axis to the image side, while the positions of the first objective lens group, the aperture stop, and the third objective lens group relative to the image plane remain unchanged. This invention's optical system for a large-aperture full-frame fixed-focus lens optimizes light refraction and convergence, balances aberrations, and improves image quality by setting the positive and negative optical powers of each lens group and the ratio between the combined focal length of each lens group and the combined focal length of the entire lens. This further enables the lens to achieve higher image quality.

A method for polarization compensation includes: (a) generating at least one beam of an electromagnetic wave; (b) sending the at least one beam through a physical medium; (c) receiving the at least one beam of an electromagnetic wave after it has traversed the physical medium; (d) measuring the intensity of the electromagnetic wave after it traverses a system of electromagnetic retarders; (e) determining the polarization of the electromagnetic wave after it traverses the system of electromagnetic retarders; (f) calculating the positions of the electromagnetic retarders to match the determined polarization of the electromagnetic wave with the polarization of the generated electromagnetic wave; and (g) compensating the effect of the physical medium on the polarization of the electromagnetic wave by setting the electromagnetic retarders according to the calculated positions.