论文部分内容阅读
光束的偏振特性在大气传输中变化比较小,因而偏振移位键控调制具有较高的可靠性。以星地激光通信为背景,研究星地激光通信链路的圆偏振移位键控调制的误码率性能。考虑到大气湍流的影响,采用Hufnagle-Valley大气折射结构常数模型,在Rytov方差分别为0.082,1.11这两种弱、强湍流起伏条件下,通过对比圆偏振移位键控调制和直接检测开-关键控调制的误码率,得到了同等湍流起伏条件下前者误码率性能比后者突出的结论。特别是Rytov方差为0.082时,要达到10-7的误码率,它们对信噪比的要求分别是21.65dB和30dB,圆偏振移位键控调制对信噪比的要求降低了8.35dB。此外,还分析了近地面折射结构常数、天顶角和地面风速这3个因素对误码率的影响,仿真结果表明圆偏振移位键控调制的误码率比直接检测开-关键控调制最少降低2个数量级。因此,圆偏振移位键控调制在未来星地激光通信中有着广阔的发展前景。
Polarization characteristics of the light beam in the atmospheric transmission changes relatively small, so the Polarization Shift Keying modulation with high reliability. Taking the ground-based laser communication as the background, the bit error rate performance of the circularly polarized shift keying modulation of the star ground laser communication link is studied. Taking into account the influence of atmospheric turbulence, the constitutive model of the atmospheric refraction of Hufnagle-Valley is used to simulate the open-close and open-field emission by contrasting the circularly polarized shift keying under the weak and strong turbulence fluctuations with Rytov of 0.082 and 1.11 respectively. The bit error rate of the key control system, the same bit error rate performance turbulence obtained under the latter than the prominent conclusion. Especially when the variance of Rytov is 0.082, to achieve a bit error rate of 10-7, their SNR requirements are 21.65dB and 30dB, respectively, and the requirement of circular polarization shift keying modulation for signal-to-noise ratio is reduced by 8.35dB. In addition, the effects of refraction constants near the ground, zenith angle and ground wind speed on bit error rate are analyzed. The simulation results show that the bit error rate of circularly polarized shift keying modulation is better than the direct detection of open-keying modulation At least 2 orders of magnitude lower. Therefore, circularly polarized shift keying modulation has broad prospects for future satellite laser communications.