复数旋转码性能的研究

基于复数旋转码已有的研究结果,本文集中讨论了有关码字的一般性能,这些性能包括码重分布、覆盖半径、超限译码能力、检纠突发错误能力、检纠突发错误同时纠随机错能力。证明了复转码某些参数表达的简便性,以及组合设计码的优越性。     

Improved List Sphere Decoder for Multiple Antenna Systems

An improved list sphere decoder （ILSD） is proposed based on the conventional list sphere decoder （LSD） and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fixed initial radius, the ILSD adopts an adaptive radius to accelerate the list cdnstruction. Characterized by low-complexity and radius-insensitivity, the proposed algorithm makes iterative joint detection and decoding more realizable in multiple-antenna systems. Simulation results show that computational savings of ILSD over LSD are more apparent with more transmit antennas or larger constellations, and with no performance degradation. Because the complexity of the ILSD algorithm almost keeps invariant with the increasing of initial radius, the BER performance can be improved by selecting a sufficiently large radius.     

Turbo码的距离特性及Viterbi译码方法

Ｔｕｒｂｏ码由递归系统卷积码（ＲＳＣ）并行级联而成,从ＲＳＣ码特有的距离特性和误码率限分析了Ｔｕｒｂｏ码的优异性能。根据码距特性提出了对角交织的优化交织法。在适当译码增益损失下,提出了Ｔｕｒｂｏ码译的Ｖｉｔｅｒｂｉ译码实现方法,并用此方法进行了计算机仿真,证明了结论的正确性。     

Accelerating BP-Based Iterative Low-Density Parity-Check Decoding by Modified Vertical and Horizontal Processes

Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity-check (LDPC) decoding over an additive white Gaussian noise (AWGN) channel, where the newly updated extrinsic information is immediately used in the current decoding round. Theoretical analysis and simulation results demonstrate that both the modified approaches provide significant performance improvements over the traditional BP algorithm with almost no additional decoding complexity. The proposed algorithm with modified horizontal process offers even better performance than another algorithm with the modified horizontal process. The two modified BP algorithms are very promising in practical communications since both can achieve an excellent trade-off between the performance and decoding complexity.     

基于单码道绝对位置编码理论的11位字长旋转编码器设计

系统介绍了单码道均布式绝对位置编码序列的性质,并给出可用序列在码型和段数方面的几点约束,同时还应用卡诺图均布式绝对位置编码理论设计了11位字长2046个位置绝对编码序列.应用该序列制作了码盘,设计并实施了小型高精度的单码道均布式绝对编码器样机,其硬件电路分为译码、置零和并串行输出接口3部分,并行接口可直接用于显示,串行接口符合RS-485标准,同时根据实际应用需求设计了按键式电置零功能.     

基于FPGA的MVBC帧收发器设计

首先分析了多功能车辆总线(multifunction vehicle bus,MVB)的通信机制与特点,在此基础上,采用VHDL语言编写了MVB总线控制器(MVB controller,MVBC)帧收发器中曼彻斯特编译码、循环冗余码校验(cychinc reduncy check,CRC)校验等核心功能的算法,设计了收发器中发送模块和接收模块;最后FPGA实现了MVB主、从数据帧的收发。     

汽车音响防盗原理和解码实例

阐述汽车音响防盗系统基本原理及锁死的解码方法,详细介绍7款代表车型的音响系统锁死后的解码过程。对驾驶、维修人员有很实用的参考价值。