Exploring Maximum Bit Rates for Software Defined Radios in Aeronautical Telemetry

Abstract

This paper investigates the maximum achievable bit rates for the SMR 7522 and USRP X410 software-defined radios (SDRs) connected to a desktop computer an IntelTM Core® i7 processor pro detecting SOQPSK-TG. We employ a new interface between the host computer and the bit error rate tester: the Lumistar LS68. The new interface converts bit decisions generated by the host computer and exported via Ethernet into clock and data signals. The new interface removes the previous limitations imposed by microcontroller-based interfaces based on a USB link. Our experiments reveal that the USRP can support bit rates up to 8.192 Mbps, while the SMR 7522 is limited to 3.90625 Mbps. We explore the factors influencing these limits, including SDR architec- tures, host computer processing capabilities, and the impact of custom resampling and automatic gain control (AGC) implementations.