This paper presents GBSense, an innovative compressed spectrum sensing system designed for GHz-bandwidth signals. GBSense introduces a novel approach to realize periodic nonuniform sampling that efficiently captures wideband signals using significantly lower sampling rates compared to traditional Nyquist sampling. The system incorporates time-interleaved analog-to-digital conversion, which eliminates the need for the complex analog delays typically required in multicoset sampling architectures, and offers real-time adjustable sampling patterns. The hardware design includes a dedicated clock distribution circuit and the implementation of a standard protocol to ensure precise synchronization of nonuniform samples. GBSense can process signals with a 2 GHz radio frequency bandwidth using only a 400 MHz average sampling rate. Lab tests demonstrate 100\% accurate spectrum reconstruction when the spectrum occupancy is below 100 MHz and over 80\% accuracy for occupancy up to 200 MHz. Additionally, an integrated system built around the GBSense core and a low-power Raspberry Pi processor achieves a low processing latency of around 30 ms per frame, showcasing strong real-time performance. This work highlights the potential of GBSense as a high-efficiency solution for dynamic spectrum access in future wireless communication systems.