High throughput channel tracking for JTRS wireless channel emulation

Abstract

Testing and verifying wireless systems in a real world environments is a challenging but an important problem. This is particular true for the Joint Tactical Radio System (JTRS) where the modulation techniques are optimized towards environments that are difficult to reproduce (e.g., ship to plane, plane to satellite communications). Such cases necessitate a wireless channel emulator to facilitate testing in the laboratory as the protocols are being developed. Furthermore, the increasing complexity of communications protocols and highly variable network scenarios force the channel emulator to support an accurate and complicated channel model that can scale to handle a large number of radios that operate across a wide frequency spectrum. We developed a unique channel impairment emulator prototype to meet these requirements. It maximizes the scalability and performance, operating in a frequency range of 2 MHz to 2 GHz. Moreover, our emulator design accommodates radio operation that use unknown frequency hopping techniques, which is increasingly common in JTRS systems. This key feature to this system is a high throughput channel tracker module that handles high bandwidth intermediate frequency (IF) signals while providing the scalability to handle a large number of channels.