﻿ EBPSK-MODEM的抗单径瑞利衰落算法 Anti-Single Path Rayleigh Fading Algorithm Based on EBPSK-MODEM

Hans Journal of Wireless Communications
Vol.05 No.04(2015), Article ID:15871,7 pages
10.12677/HJWC.2015.54011

Anti-Single Path Rayleigh Fading Algorithm Based on EBPSK-MODEM

Chenmei Zhang, Lenan Wu

Radio Engineering Department of Southeast University , Nanjing Jiangsu

Email: chenmei_zhang@163.com

Received: Jul. 23rd, 2015; accepted: Aug. 10th, 2015; published: Aug. 14th, 2015

ABSTRACT

Extended Binary Phase Shift Keying (EBPSK) is an efficient modulation mode. According to the characteristic that the impacting filter based demodulator would transform the EBPSK modulating signal into impact amplitude, and the interpolation thought, two new anti-single path Rayleigh fading algorithms aimed at EBPSK-MODEM scheme are put forward, which are interpolation algorithm estimating fading factor and interpolation algorithm estimating the decision threshold. The simulation results show that the two algorithms improve the performance of EBPSK-MODEM systems to varying degrees. Among them, the performance of the interpolation algorithm estimating decision threshold is slightly better than interpolation algorithm estimating fading factor.

Keywords:EBPSK-MODEM, Single Path Rayleigh Fading Channel, Impacting Filter, Interpolation Algorithm Estimating Decision Threshold, Interpolation Algorithm Estimating Fading Factor

EBPSK-MODEM的抗单径瑞利衰落算法

Email: chenmei_zhang@163.com

1. 引言

2. 基本原理

2.1. EBPSK调制与解调

(1)

(2)

EBPSK调制信号经过冲击滤波器后的波形如图1所示(其中K = 2，N = 10)，在码元“1”中，K个载波周期的相位跳变经过冲击滤波器后变为寄生调幅[8] [9] ，然后可采用包络检波和门限判决解调出“0”和“1”。因此可直接在中频上对发送码元进行判决，无需基带处理。

2.2. 单径瑞利衰落信道建模

(3)

(a)(b)

Figure 1. EBPSK waveform and filter output waveform

(4)

3. 抗单径瑞利衰落算法

3.1. 插值估计衰落因子算法

(5)

(a)(b)

Figure 2. The waveform of EBPSK after impacting filter

(6)

1) 在发送码元中，间隔k个插入训练码元“1”即，其中为发送码元序列。

2) 在接收端，根据，计算得到，然后采用线性插值估计分别为训练码元的EBPSK调制信号通过和未通过单径瑞利衰落信道的冲击滤波器后冲击幅度值序列)。

3) 最后计算得到，用于门限判决从而得到解调信号。

3.2. 插值估计判决门限算法

(a)(b)

Figure 3. Interpolation estimation a(n)

1) 在发送码元中，间隔k个插入相邻两个训练码元“1”和“0”即，其中为发送码元序列。

2) 在接收端，根据接收到的(分别为训练码元“1”和“0”的EBPSK调制信号经过冲击滤波器后冲击幅度值序列)，进行线性插值估计，得到

3) 根据，计算得到判决门限，最后利用实时判决门限进行门限判决，得到解调信号。

4. 仿真结果

Figure 4. Interpolation estimation decision threshold tracking

Figure 5. Performance comparison of EBPSK system with different resistance to single path Rayleigh fading

5. 结束语

Anti-Single Path Rayleigh Fading Algorithm Based on EBPSK-MODEM. 无线通信,04,75-82. doi: 10.12677/HJWC.2015.54011

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