A USRP-Based Testbed for Wideband Ranging and Positioning Signal Acquisition

Abstract

For validation and demonstration of high accuracy ranging and positioning algorithms and systems, a wideband radio signal generation and acquisition testbed, tightly synchronized in time and frequency, is needed. The development of such a testbed requires solutions to several challenges. Tight time and frequency synchronization, derived from a centrally distributed timefrequency reference signal, needs to be maintained in the hardware of the transmitter and receiver nodes, and wideband signal acquisition requires sustainable data throughput between receiver and host PC as well as data storage at GB level.This paper presents a testbed for wideband radio signal acquisition, for validation and demonstration of high accuracy ranging and positioning. It consists of multiple Ettus X310 USRPs and supports high accuracy (<100 ps) time-deterministic, sustainable signal transmission and acquisition, with a bandwidth up to 320 MHz (in dual channel mode) and frequencies up to 6 GHz. Generation and processing of wideband arbitrary signal waveforms, is done offline. To realize these features, RFNoC compatible HDL units were developed for integration in the X310 SDR platform. Wideband transmission and signal acquisition at a lower duty cycle is applied to reduce the data offloading throughput to the host PC. Benchmarking of the platform was performed to demonstrate sustainable long duration dual channel acquisition. Indoor range measurements with synchronous operation of the testbed show a decimeter-level accuracy.

Decimeter Positioning in an Urban Environment Through a Scalable Optical-Wireless Network

“…FPGA that permit it to store a ranging signal burst and perform periodic synchronized transmissions (Diouf et al, 2021). A transmitter USRP is operated as follows.…”

“…This problem can be solved by using a low duty cycle ranging signal. A custom HDL unit was developed which implements temporary storage of the received ranging signal burst samples on the USRP followed by their transfer to the host PC at a sustainable data rate (Diouf et al, 2021). Under these conditions, the receiver USRP only captures the samples taken from the 160 µs time window that contains the ranging signals.…”

Spectrum Sensing Using Software Defined Radio for Cognitive Radio Networks: A Survey

“…For instance, the transmission or acquisition of data streams through a given number of antenna requires to be executed simultaneously at the same time, while most available SDR boards are limited by the number of antennas. It has motivated the implementation of multi-antenna testbeds integrating several SDR boards [85]- [87]. In doing so, a synchronization module for sharing reference signals is incorporated.…”

“…1 GbE), will be limited to stream up to 25 Msps (for 16-bit samples), thus creating a bottleneck for larger values of Msps and consequently for larger bandwidths. This is the case in [87], where the authors require a sustainable signal acquisition at very high sampling rates, and consequently high data rate throughput and storage (e.g. 400 Msps covering a bandwidth of 320 MHz).…”