5results about How to "Improve bit error rate" patented technology

The application discloses a laser microwave hybrid communication adaptive modulation method based on machine learning, comprising: acquiring a weather data set, and establishing a channel state set according to weather data in the weather data set; training a random forest model RFM by using the weather data set and the channel state set, and obtaining the trained random forest model RFM; acquiring real-time weather data, inputting the weather data into the trained random forest model RFM, and obtaining a current optimal channel state D i ; judging whether an average error rate P i under the current channel state D e is less than a target error rate P e,obj , if not, adjusting the random forest model RFM until the current average error rate P e is less than the target error rate P e,obj , and simultaneously judging whether the currently executed channel state is consistent with the optimal channel state, if not, executing channel state switching, and completing switching of the laser microwave hybrid link. The influence of bad weather on the channel is reduced, and the communication efficiency is improved.

This invention discloses a high-density ferroelectric memory, its fabrication method, and its applications, belonging to the field of semiconductor memories. The memory consists of an array of multiple memory cells connected on both sides by substantially orthogonal word lines and bit lines. The memory cell of this invention employs a stacked structure of a top electrode, a resistive switching dielectric layer, an intermediate metal layer, a ferroelectric dielectric layer, and a bottom electrode, electrically equivalent to a ferroelectric capacitor connected in series with a resistive switching selector. By adjusting the RC delay of the memory cell, the voltage drop across the ferroelectric capacitor in the unselected cell is reduced, thus reducing its disturbance. Furthermore, the ferroelectric capacitor has a stable capacitance value, which can be effectively reduced by RC regulation to mitigate the impact of disturbance voltage. In summary, this invention increases the memory's storage window and reduces the bit error rate without increasing additional area overhead.

The invention is suitable for the technical field of laser communication, and provides a turbulence disturbance-oriented optical communication emission gain intelligent adjustment method, which comprises the following steps of: acquiring atmospheric turbulence channel state information in real time, constructing a turbulence disturbance intensity evaluation model, and outputting a current turbulence disturbance level; matching the turbulence disturbance level with a preset multi-level transmitting gain strategy table, and determining a target transmitting power gain value; the driving current of the laser transmitting end is dynamically adjusted through a self-adaptive feedback mechanism, continuous circulation execution is performed, and a closed feedback loop is formed. The turbulence channel state information is collected in real time, the turbulence disturbance intensity evaluation model is constructed, the multi-stage transmission gain strategy table is matched, the difference value between the actual transmission gain and the target value is controlled within the preset error range through the self-adaptive feedback mechanism, and the feedback correction step length is dynamically adjusted in combination with the turbulence intensity grade. The system can quickly respond to turbulence changes, and the bit error rate and the stability of a communication link are improved.

The adjustable multi-aperture laser communication receiving system belongs to the technical field of visible light communication, in order to solve the problems existing in the prior art, the system comprises a plurality of receiving telescopes corresponding to a plurality of motors respectively arranged in a receiving telescope array, the plurality of motors are connected to a connecting rod, a plurality of narrowband optical filters are respectively arranged at the exit ends of the plurality of receiving telescopes, and the target surfaces of a plurality of photodetectors are respectively located at the focal plane positions of the plurality of receiving telescopes; the plurality of photodetectors are connected with a merging circuit module, the merging circuit module is connected with a digital-to-analog conversion module, the digital-to-analog conversion module is connected with a demodulation module, and the demodulation module is connected with a host computer; the host computer is connected with a controller and a radar respectively, and the controller is connected with the plurality of motors; the host computer drives the plurality of motors to change the relative position, the pitch angle and the left-right angle of each receiving telescope and the connecting rod through the controller. When the laser communication across the air-sea interface is carried out, the communication performance of the receiving system is improved.

The application provides a blind carrier phase recovery method and system for optical fiber communication. At the sending end, first, the QAM symbol stream is grouped, and a reference pilot with a specific fixed amplitude is inserted according to the quadrant in which the first symbol of each symbol group is located. At the receiving end, after the preliminary blind carrier phase estimation is completed, the original quadrant corresponding to the reference pilot is identified by using the minimum Euclidean distance detection mechanism, and then the actual quadrant position of the pilot in the received signal is compared, so as to analyze the phase ambiguity offset with 90 degrees as the base, and accordingly, the phase correction is implemented on the corresponding symbol group. The application effectively breaks through the four-fold rotational symmetry limitation of the traditional constellation diagram by means of amplitude modulation coding, and can accurately identify and correct the fixed-angle phase deviation occurring in the blind phase recovery process. The method can significantly suppress the error code diffusion caused by the phase ambiguity, improve the transmission performance of the system in terms of the bit error rate and the generalized mutual information, and has good algorithm compatibility and engineering implementation convenience, and the system overhead is effectively controlled.