Testing the Reliability and Flexibility of Digitizers Adapting the RF/IF Signals over IP Applications Using a Testbed Platform

As physical constraints can be challenging for Radio Frequency (RF) telemetry, a new solution has been exploited to support the demand for RF transmissions. As frequency spectrum gets crowded with more technologies, a solution to a reliable transmission is needed. Digitizers can mitigate many of the physical constraints in order to achieve a successful RF transmission. The method includes the conversion of the RF signals to be sent over IP networks, transmit and de-convert the signal. IP networks will mitigate many disadvantages over a regular signal transmission. The authority in charge to allocate frequency bands is the Federal Communications Commission (FCC). FCC performs different Advanced Wireless Service (AWS) a term used to allocate the licensed bands to all users. For example, government, cellular companies, television, radio and much more. Numerous AWS have been performed to allocate new services or reallocate existing services due to high demand of the RF spectrum. The digitizers are also able to preserve both frequency and timing characteristics, and then accurately reconstructing the original Telemetry signals to enable processing, recording or re-transmission at another location. To characterize the digitizers, a Software Defined Radio (SDR) testbed with an external reference clock to analyze the impact of signal synchronization is used. Several experiments were done with different modulation schemes, destination IP, gain, packet size and others. Also, the utilization of a reference clock to perform testing will be added to compare result with the reference clock and in absence. The configurations of gain, bandwidth and frequency are also parameters of interest. In order to compare these results, diverse parameters were used to qualify and quantify the signal. In addition, the flexibility of SDR’s and digitizers provide, allow to test several scenarios. Furthermore, using the same concept for RF over IP, experiments were also done with LTE signals to perform the same process and measure certain parameters. To summarize, a set of RF over IP tests yielded results for comparison, mostly with the reference clock to make this layer as transparent as possible and characterize the limitations or other challenges that could be present with this solution