Frequency hopping (FH) communications are widely used in Satcom systems. The latest FH systems have exceeded 3 GHz with hop rates up to 100 000 hops/s. Traditional spectrum sensing systems hardly monitor such signals. Modulated wideband converter (MWC) is an emerging compressive sampling structure applied to sample multiband signals. This article analyses the effects of the nonlinearity of analog devices and proposes an optimization method based on a greedy algorithm for mixing sequences to make reconstruction performance uniform across sub-bands. To correct the errors caused by the nonideality of analog front end circuits between the theoretical sensing matrix and the practical one, we also develop a calibrating method that obtains all the sensing matrix coefficients through a single measurement. In conventional MWC, out-band noise will be blended during reconstruction. Instead of matrix factorization, we reserve signal characters and designed sliding filters to improve narrowband signals reconstruction sensitivities. We produced a four-branch MWC principle prototype for FH signal detection. The sensing bandwidth is 3 GHz, and the sampling rate is 400 MHz, whereas the reconstruction sensitivity is as low as 13-dB in-band signal-to-noise.

中文翻译：

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用于超宽带跳频信号检测的混频优化调制宽带转换器的实现

跳频 (FH) 通信广泛用于卫星通信系统。最新的 FH 系统已超过 3 GHz，跳频高达 100 000 跳/秒。传统的频谱感测系统很难监测此类信号。调制宽带转换器 (MWC) 是一种新兴的压缩采样结构，适用于对多频带信号进行采样。本文分析了模拟设备非线性的影响，并提出了一种基于贪心算法的优化方法，用于混合序列，使重建性能跨子带均匀。为了纠正由模拟前端电路在理论传感矩阵和实际传感矩阵之间的非理想性引起的误差，我们还开发了一种校准方法，通过一次测量获得所有传感矩阵系数。在传统的 MWC 中，带外噪声将在重建过程中混合。我们保留了信号特征并设计了滑动滤波器，而不是矩阵分解，以提高窄带信号重建灵敏度。我们制作了一个用于 FH 信号检测的四分支 MWC 原理原型。传感带宽为 3 GHz，采样率为 400 MHz，而重建灵敏度低至 13 dB 带内信噪比。