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This chapter contains sections titled: Logical channels Physical channels Synchronization Mapping of logical onto physical channels Radio subsystem link control Channel coding, source coding and speech processing Source coding and speech processing Channel coding Power‐up scenario

The quality of the captured point cloud and the scanning speed of a structured light 3D camera system depend upon their capability of handling the object surface of a large reflectance variation in the trade-off of the required number of patterns to be projected. In this paper, we propose and implement a flexible embedded framework that is capable of triggering the camera single or multiple times for capturing single or multiple projections within a single camera exposure setting. This allows the 3D camera system to synchronize the camera and projector even for miss-matched frame rates such that the system is capable of projecting different types of patterns for different scan speed applications. This makes the system capturing a high quality of 3D point cloud even for the surface of a large reflectance variation while achieving a high scan speed. The proposed framework is implemented on the Field Programmable Gate Array (FPGA), where the camera trigger is adaptively generated in such a way that the position and the number of triggers are automatically determined according to camera exposure settings. In other words, the projection frequency is adaptive to different scanning applications without altering the architecture. In addition, the proposed framework is unique as it does not require any external memory for storage because pattern pixels are generated in real-time, which minimizes the complexity and size of the application-specific integrated circuit (ASIC) design and implementation.

Space optical communication has been a hot topic in modern communication system research, because it has many advantages, such as good secrecy, large information capacity, strong anti-interference ability, and so on. Pulse position modulation (PPM) is an excellent modulation method. In view of the low rate of information transmission by a space optical communication system, an improved \"empty-empty-zero\" physical frame format is designed to improve its transmission rate. In view of the actual space laser digital receiver, the frame synchronization algorithm is designed in this paper. Based on the physical frame format, this paper focuses on the design of frame synchronization algorithm. In order to deal with the change of noise and other parameters, an adaptive threshold setting is proposed. Considering the engineering implementation, a simplified correlation filtering implementation method is proposed. Finally, we designed the reception prototype system based on FPGA. The Matlab simulation, online simulation and experimental verification prove that the proposed method is correct and reliable. 空间光通信具有保密性好，信息容量大，抗干扰能力强等优点，是现代通信系统研究的热点之一。脉冲位置调制（pulse position modulation，PPM）是空间光通信系统中一种性能优良的调制方式。针对空间光通信系统中信息传输速率低，设计了一种改进的\"空-空-零\"的物理帧格式，以提高空间光通信系统的传输速率。针对实际空间激光数字接收机，深入开展了帧同步算法设计研究。结合设计的物理帧格式，重点研究了帧同步算法的设计，为了应对噪声等参数的变化，提出自适应相关阈值设置；考虑到工程实现，提出了一种相关滤波简化实现方法等。最后，基于FPGA完成了接收机原型系统设计，经Matlab仿真、在线仿真以及实际测试表明了该设计方案的正确性和可靠性。

This paper outlines a package synchronization scheme for blind speech watermarking in the discrete wavelet transform (DWT) domain. Following two-level DWT decomposition, watermark bits and synchronization codes are embedded within selected frames in the second-level approximation and detail subbands, respectively. The embedded synchronization code is used for frame alignment and as a location indicator. Tagging voice active frames with sufficient intensity makes it possible to avoid ineffective watermarking during the silence segments commonly associated with speech utterances. We introduce a novel method referred to as adaptive mean modulation (AMM) to perform binary embedding of packaged information. The quantization steps used in mean modulation are recursively derived from previous DWT coefficients. The proposed formulation allows for the direct assignment of embedding strength. Experiment results show that the proposed DWT-AMM is able to preserve speech quality at a level comparable to that of two other DWT-based methods, which also operate at a payload capacity of 200 bits per second. DWT-AMM exhibits superior robustness in terms of bit error rates, as long as the recovery of adaptive quantization steps is secured.

This paper presents a novel approach for blind audio watermarking. The proposed scheme utilizes the flexibility of discrete wavelet packet transformation (DWPT) to approximate the critical bands and adaptively determines suitable embedding strengths for carrying out quantization index modulation (QIM). The singular value decomposition (SVD) is employed to analyze the matrix formed by the DWPT coefficients and embed watermark bits by manipulating singular values subject to perceptual criteria. To achieve even better performance, two auxiliary enhancement measures are attached to the developed scheme. Performance evaluation and comparison are demonstrated with the presence of common digital signal processing attacks. Experimental results confirm that the combination of the DWPT, SVD, and adaptive QIM achieves imperceptible data hiding with satisfying robustness and payload capacity. Moreover, the inclusion of self-synchronization capability allows the developed watermarking system to withstand time-shifting and cropping attacks.

The controllers of three-phase grid-connected inverters usually require improvements to meet the stringent grid codes with the fault-ride-through (FRT) capability. Therefore, the performance of the grid-connected inverter depends on the quality of the selected phase-locked loop (PLL). This paper proposes a PLL method that has greater accuracy and better dynamics under an unbalanced and highly distorted voltage. The proposed method is based on the least squares technique using the Levenberg-Marquardt algorithm with adaptive initial parameters for rapid convergence to the solution. The simulated and experimental results under unbalanced and harmonic voltage validated the performance of the proposed method.