We design a receiver assembling several photomultipliers (PMTs) as an array to increase the field of view (FOV) of the receiver and adapt to multiuser situation over None-line-of-sight (NLOS) ultraviolet (UV) channels. Channel estimation and signal detection have been investigated according to the space division characteristics of the structure. Firstly, we adopt the balanced structure on the pilot matrix, analyze the channel estimation mean square error (MSE), and optimize the structure parameters. Then, with the estimated parameters, an analytical threshold detection rule is proposed as a preliminary work of multiuser detection. The detection rule can be optimized by analyzing the separability of two users based on the Gaussian approximation of Poisson weighted sum. To assess the effect of imperfect estimation, the sensitivity analysis of channel estimation error on two-user signal detection is performed. Moreover, we propose a successive elimination method for on-off keying (OOK) modulated multiuser symbol detection based on the previous threshold detection rule. A closed-form upper bound on the detection error rate is calculated, which turns out to be a good approximation of that of multiuser maximum-likelihood (ML) detection. The proposed successive elimination method is twenty times faster than the ML detection with negligible detection error rate degradation.

翻译：我们设计了一种接收机，将多个光电倍增管（PMT）排列成阵列，以增加接收机视场角（FOV）并适应非视距（NLOS）紫外（UV）信道下的多用户场景。根据该结构的空分特性，研究了信道估计与信号检测问题。首先，我们在导频矩阵上采用平衡结构，分析了信道估计均方误差（MSE），并优化了结构参数。然后，利用估计的参数，提出了一种解析阈值检测规则，作为多用户检测的初步工作。基于泊松加权和的高斯近似，通过分析两用户的可分离性，可对该检测规则进行优化。为评估非理想估计的影响，我们针对信道估计误差对两用户信号检测进行了灵敏度分析。此外，基于先前的阈值检测规则，我们提出了一种用于开关键控（OOK）调制多用户符号检测的逐次消除方法。计算了检测错误率的闭式上界，该上界被证实是多用户最大似然（ML）检测错误率的良好近似。所提出的逐次消除方法相比ML检测速度快二十倍，而检测错误率的退化可忽略不计。