Recently, some technological issues in network slicing have been explored. However, most works focus on the physical resource management in this research field and less on slice selection. Different from the existing studies, we explore the problem of intelligent multiple slice selection, which makes some effort to dynamically obtain better user experience in a changeable state. Herein, we consider two factors about user experience: its throughput and energy consumption. Accordingly, a distributed E‐cross learning algorithm is developed in the multiagent system where each terminal is regarded as an agent in the distributed network. Furthermore, its convergence is theoretically proven for the dynamic game model. In addition, the complexity of the proposed algorithm is discussed. A mass of simulation results are presented for the convergence and effectiveness of the proposed distributed learning algorithm. Compared with greedy algorithm, the proposed intelligent algorithm has a faster convergence speed. Besides, better user experience is attained effectively with multiple slice access.

Linear‐frequency‐modulated continuous‐wave (LFMCW) radars with deramping technique have several advantages such as compact size, low cost, and easy implementation, compared to traditional pulse radars; however, the non‐linear distortions caused by analogue modules, particularly power amplifiers, may deteriorate the radar detection performance. To solve this problem, a digital closed‐loop compensation scheme for the LFMCW signal is proposed, which can compensate the LFMCW signal in real time, when the non‐linear distortions change with the working environment. The proposed compensation scheme improves the detection performance, noticeably. Considering the speed limitations of field programmable gate arrays (FPGAs), the proposed scheme is implemented in an FPGA at an intermediate‐frequency level, using a polyphase processing structure.

Compared with the standard estimation of signal parameters via rotational invariance technique (ESPRIT) for direction of arrival estimation, the propagator‐based ESPRIT is a more computationally efficient method since it requires no eigenvalue decomposition when calculating the signal subspace. In this study, the propagator‐based ESPRIT method is analysed by deriving its theoretical asymptotic error. With first‐order perturbation analysis, it is shown that both propagator‐based ESPRIT and standard ESPRIT have the same asymptotic error with high signal‐to‐noise ratio. Simulation results of both the propagator‐based ESPRIT and the standard ESPRIT are presented, and they are shown to be consistent with the theoretical derivations.

A wideband digital transmitting beamformer based on linear frequency modulation (LFM) signals is presented in this study. The wideband beamformer is realised as a combination of direct digital synthesisers and fractional delay (FD) filters in polyphase structure. By using coordinate rotation digital computer algorithm, high intermediate frequency wideband LFM signal is generated and phase compensation for beamforming is accomplished in field programmable gate array. The impact of different number of quantisation bits on signal generation is analysed. The results of waveform generation and FD filter design are given. At last, the transmitting beam pattern is simulated.

Multicarrier signals using orthogonal frequency division multiplexing (OFDM) bring many advantages to radar such as low probability of intercept, improved target detection performance, optimisation of both radar transmitter and receiver etc. A major drawback of multicarrier OFDM signals is their high peak‐to‐mean envelope power ratio, which reduces the working efficiency of the used power amplifiers. To solve this problem, a digital constant‐envelope modulation scheme is proposed for radar using multicarrier OFDM signals. The scheme can transmit multicarrier OFDM signals through power amplifiers being operated near saturation levels (and thus maximising power efficiency) with little spectral distortion, even in the presence of channel mismatch. Given the speed limitations of field programmable gate arrays (FPGAs), the proposed scheme is implemented in an FPGA at intermediate frequency level using a polyphase processing structure.

For guaranteeing quasi-error free delivery of realtime multicast services over wireless networks, an efficient greedy algorithm is proposed for optimizing the parameters of a HARQ scheme with rateless codes under strict delay and bandwidth constraints. We take systematic Raptor codes as an example for analyzing the optimum performance of the HARQ scheme. The results show that the optimum performance can be obtained by combining the optimum HARQ and FEC. Additionally, the simulation results show that the proposed optimization framework can be used for evaluating the tight lower bound performance of the HARQ, which indicates that it is suitable for designing optimum HARQ scheme with guaranteeing the target quasi-error free delivery requirements very well.