16-QAM is a type of Quadrature Modulation (QAM) in which a carrier wave of a fixed frequency can exist in one of sixteen different states. This can be represented in a constellation diagram (Figure 1) where each state is a symbol that contains one of 16 different amplitude and phase leve...
a圖4(a)所示為一個16-QAM訊號星座圖,且每一符元皆有唯一映對的資料位元內容,反觀16-QAM延伸星座圖方案,則是部分符元具有二個可映對的資料位元內容 Chart 4(a) shows is a 16-QAM signal star map, also each Fu Yuanjie has only reflects to the material element content, instead observes 16-QAM to...
d2 level . There are many variants to this technique. Most popular are 16-QAM, 64-QAM and256-QAM. The example below explains 16-QAM. The 16 qam bits per symbol are 4 (four). This means in 16-QAM each symbol represents 4 bits as mentioned in the 16-QAM constellation diagram above....
在附图中图1显示了有关16-元QAM的信号星座图(constellation diagram);图2显示了根据本发明实施例,在采用16-元QAM的数据通信系统中确定输入到信道解码器的4个解调码元的软值的过程;图3显示了根据本发明实施例,执行确定解调码元的软判决值的过程的方块图;和图4显示了根据本发明实施例,在采用16-元QAM的数据通信系统...
QAM是一种频谱利用率很高的调制方式,相对于传统的QPSK调制方式,更适应于卫星通信对高速数据传输的需求。为深入研究QAM调制原理,本文利用Simulink工具搭建了16QAM信号基带传输模型,并通过观察仿真出的信号频谱、星座图、眼图、传输误比特率等信息,对16QAM调制解调技术的基带传输特性进行了进一步的研究。最后指出了16 QAM...
M = 16;% Modulation orderx = (0:15);% Integer inputsymbin = qammod(x,M,'bin');% 16-QAM output (binary-coded)symgray = qammod(x,M,'gray');% 16-QAM output (Gray-coded) Use thescatterplotfunction to plot the constellation diagram and annotate it with binary (red) and Gray (...
图1 接收信号星座图Fig.1 The constellation of receive signal 图2 正交接收机示意图Fig.2 The diagram of I/Q receiver 1.2 在二维调制干扰下M-QAM的误码率分析 M-QAM信号可以认为是两路正交信号的合成[12]。在M-PAM调制中,任意两点的最小欧氏距离dmin定义为 (5) 其星座点位于其中M表示在某维上映射值的...
圖4所示為一使用格雷映對 (Gray mapping) 的16-QAM星座圖及其CES。圖4(a)所示為一個16-QAM訊號星座圖,且每一符元皆有唯一映對的資料位元內容,反觀16-QAM延伸星座圖方案,則是部分符元具有二個可映對的資料位元內容问题补充:匿名 2013-05-23 12:21:38 正在翻译,请等待... 匿名 2013-05-23 12:23:...
aFor OFDM with QPSK simulation, constellation diagram of transmitted signal and received signal is shown in Figure 5. The OFDM with 8-QAM and 16-QAM mapping simulation are analyzed for BER performance and compared with 8-PSK and 16-PSK systems simulation as shown in Figure 6. 为OFDM以QPSK模...
研究表明,在非线性的卫星信道中,通过合理地设计APSK信号的星座图,其误码率性能优于 QAM调制[2]。因此,16APSK和32APSK已被应用于DVB-S2标准[3]。载波频偏估计方法可分为数据辅助和非数据辅助两种。数据辅助的频偏估计方法需要插入导频序列,从而导致数据传输效率的降低。因此,导频序列应该尽量短,但随着导频序列长度...