Interleaved Reception in LoRa Using IFT: A Hardware-Efficient Architecture for Fast and Low-Power Image Transmission

Long-range (LoRa) communication has emerged as a preferred low-power protocol for Internet of Things (IoT) applications in remote or infrastructure-limited environments. However, its constrained data rate poses significant challenges for transmitting high-volume data, such as images. This article presents a novel interleaved frequency transmission (IFT) framework that employs a dual-receiver architecture to significantly reduce transmission time and energy consumption for LoRa-based image communication. By alternating packet transmissions between two frequencies (915 and 914.5 MHz), the system effectively bypasses receiver-side processing delays and enables pseudo-parallel data reception. Experimental results demonstrate that IFT achieves up to 50% reduction in image transmission time and up to 59% energy savings on the transmitter side compared to traditional single frequency transmission (SFT), without requiring changes to the physical layer. Field tests across diverse environments on a Norfolk State University campus further validate the robustness of IFT, showing consistent improvements in packet reception rate, signal-to-noise ratio, and received signal strength indicator, especially in semi-obstructed areas. The proposed IFT architecture is implemented using Raspberry Pi Zero W and SX1276 LoRa modules and is evaluated under real-world deployment conditions. The findings suggest that IFT is an energy-efficient solution for visual IoT applications in agriculture, environmental monitoring, and remote sensing. Future work will explore ultralow-power microcontroller integration to further enhance system viability for long-term deployments.