臺灣博碩士論文加值系統

由於結合頻率和相位的調變方式能夠增加頻寬效能並且兼顧功率效
能,故在決定調變方法時,是一種值得考慮的選擇.本論文所討論的調變方
法:固定能量頻率相位調變(CEFPM),是將能量固定,頻率和相位則為可調之
任意數目,並在一個字元中包含兩個頻率及一個相位;因為它是一種新的調
變,所以本文先就同調相檢測加上AWGN通道模型加以探討.在計算CEFPM的
位元錯誤機率時,我們需要知道如何分配兩個頻率上的振幅,如何找出各種
訊號間距和具有各種間距的位元數,因此,本文提出了函數轉換法,以完成
上述工作.本論文將找出改變頻率數目時,對位元錯誤機率和功率頻譜密度
所造成的影響;並就位元錯誤機率和功率頻譜密度這兩方面和QFPM及
NFSK/4PSK做個比較,並由這些比較中發現,CEFPM因訊號之間具有凝聚性,
會使得CEFPM的頻寬效能比QFPM和NFSK/4PSK高,但也因此在位元錯誤機率
的性能方面不如QFPM和NFSK/4PSK,這是CEFPM和另兩個調變訴求不同的地
方;另外在CEFPM未來發展方面,也有所說明.

The method combining frequency and phase modulation can
enhance the bandwidth efficiency and at the same time retain the
power efficiency of MFSK. So, it is worth studying in detail.
This thesis investigates the coherent detection of orthogonal
constant-energy frequency-phase modulation(CEFPM) over the AWGN
cahnnel. It includes two frequency and one phase parameters to
represent one CEFPM signal. How to distribute the energy between
the two frequencies we use and the error coefficients in the BEP
equation are needed. A method called transfer function approach
will be proposed in this thesis. In this thesis we will discuss
three topics: 1. The influences on BEP and PSD by changing the
number of frequencies and phases. 2. The comparisons between
CEFPM, QFPM and NFSK/4PSK in BEP and bandwidth efficiency. We
find out the bandwidth efficiency of CEFPM is better than that
of QFPM and NFSK/4PSK. The error performance in QFPM and NFSK/4
PSK is better than that of CEFPM. The reason in both is the
coherence of signals in CEFPM. 3. The advantages and future
development of CEFPM.