In order to meet the requirements of large instantaneous bandwidth, wide operating frequency range, large dynamic range, and anti-interference for microwave parameter measurement in the new generation radar system and real-time signal processing system, a microwave photonic Doppler frequency shift (DFS) and angle of arrival (AOA) measurement scheme based on Mach–Zehnder modulator (MZM) and acousto-optic modulator (AOM) is proposed in this article. The designed structure can clearly identify the direction of the DFS and avoid the intermodulation distortion and low-frequency interference. In addition, the upper and lower optical sidebands are fully utilized to effectively avoid the frequency error caused by the AOM driver module and improve the measurement accuracy of the system. In the experiment, the error of the microwave DFS at an ultrawide operation frequency from 6 to 36 GHz is between ±0.15 Hz with a clear direction. The micro-DFS (mDFS) measurement is also carried out to demonstrate the advantage of low-frequency DFS measurement. It is also verified that the phase difference error is less than 1° in the AOA measurement experiment. The proposed scheme has advantages such as multifunction and anti-interference, thus having great application prospects.

Doppler frequency shift (DFS) and angle of arrival (AOA) measurements play a crucial role in modern radar, aviation, and satellite communication systems. Rydberg atom-based receivers are renowned for the high sensitivity, wide operating frequency range, and immunity to electromagnetic interference in microwave electric field sensing. In this work, the concept of electromagnetically induced transparency (EIT) with Rydberg atoms, along with heterodyne mixing techniques, is employed to accurately measure both the DFS and AOA of microwave field within a unified experimental system. The proposed scheme utilizes the dual-coupled beams in the Rydberg atom vapor cell to reduce experimental errors and improve the measurement accuracy. The experimental results indicate that within the frequency measurement range from 11 to 18 GHz, the experimental error in measuring the DFS of different Rydberg states is within ±0.5 Hz, showcasing the wideband tunability of the system. Moreover, the AOA measurement for the echo signal reveals that the measurement error is less than 0.5° within the range from −30° to 35°. This research shows the first instance of simultaneously measuring DFS and AOA within the same Rydberg atom system. Additionally, by introducing the concept of “relative frequency zero point” in DFS measurement for the first time, the differentiation of the direction of the DFS can be identified. Furthermore, the accuracy of AOA measurement based on Rydberg atoms has been further improved in this research. Overall, this research provides a novel approach for measuring DFS and AOA using Rydberg atomic system.

A microwave photonic instantaneous frequency and angle of arrival (AOA) measurement method based on a Sagnac loop is proposed and demonstrated in this paper. By establishing a monotonic relationship between the phase difference and the direct current (dc) amplitude, an amplitude comparison function (ACF) is constructed to achieve AOA measurement. Meanwhile, the instantaneous frequency measurement (IFM) is achieved by introducing optical delay. By adjusting the optical delay, the scheme can not only tune the frequency measurement range but also increase the measurement accuracy. The experiment results prove that the phase difference error of the AOA measurement is less than 1 degree, and the IFM measurement error in the frequency range of 0.5-36 GHz is ±0.2 GHz. The scheme has the characteristics of multi-function, simple structure and large bandwidth, it has a great competitive advantage in the future electronic applications.

Computing tasks offload of the edge computing has a significant impact on edge devices energy consumption and load balancing. To reduce the total cost, an offloading strategy that combines energy consumption and load balancing degree is proposed. A task partitioning model is given to perform fine-grained division of computing tasks. Furthermore, the energy consumption model of computing task offloading is obtained through the time delay model, and then the cost function of computing task offloading is constructed in combination with the load balancing degree and energy consumption. With the task offloading strategy, the minimum cost of task offloading is obtained under the multiple constraints, and the path of computing task offloading is determined. The simulation results demonstrate that the strategy can significantly improve the load balancing of the edge server and the overall performance of the edge server.

In contrast to phased array (PA), frequency diverse array (FDA) offers enhanced flexibility in beam scanning across both directional and distance dimensions. However, the existing FDA signal generation techniques encounter several challenges, including limited bandwidth, spurious distortion, and complexities in multi-channel tuning. In this paper, an FDA signal generation and beamforming method based on dual optical frequency combs (OFCs) is proposed. In the experiment, five-channel FDA signals with a center frequency of 8 GHz and a frequency offset of 1 MHz are generated. The power level flatness of the FDA signals remains below 2.5 dB with a remarkable spurious suppression ratio of 27.2 dB, indicating the ability of the proposed method to generate high-quality FDA signal, so as to realize the desired beamforming and scanning. The demonstrated beampattern exhibits a distinctive “S” shape, which is influenced by the distance and angle. Similarly, the generation of broadband FDA is demonstrated experimentally. Moreover, “X”-shaped beampattern can be realized by altering the distribution of the element, including the multi-carrier FDA and symmetrical FDA. The features of broad operational bandwidth, flexible frequency tunability and high spectrum purity make the proposed method a promising solution for various future applications.

A microwave photonic Doppler frequency shift (DFS) and angle of arrival (AOA) measurement method based on a dual-parallel dual-drive Mach–Zehnder modulator (DP-DDMZM) is proposed and demonstrated. A sawtooth wave signal is used to drive the DC port of the modulator to realize the optical frequency shift, and thus the direction discrimination of DFS is realized. Due to single-sideband modulation, the proposed system can avoid periodic power fading and the separation of the remote antenna unit (RAU) and central office (CO) can be achieved. In the experiment, the microwave DFS is estimated with a clear direction and a maximum measurement error of 0.25 Hz over an ultrawide operation frequency from 6 to 36 GHz. The experiment also proves that the phase error of AOA measurement is less than 1.5 degrees. Compared with the traditional electronic microwave measurement scheme, the proposed scheme has great competitive advantages in future broadband electronic applications due to the features of multifunction, large bandwidth and anti-interference.