483 research outputs found
A Sub-Terahertz Sliding Correlator Channel Sounder with Absolute Timing using Precision Time Protocol over Wi-Fi
Radio channels at mmWave and sub-THz frequencies for 5G and 6G communications
offer large channel bandwidths (hundreds of MHz to several GHz) to achieve
multi-Gbps data rates. Accurate modeling of the radio channel for these wide
bandwidths requires capturing the absolute timing of multipath component (MPC)
propagation delays with sub-nanosecond accuracy. Achieving such timing accuracy
is challenging due to clock drift in untethered transmitter (TX) and receiver
(RX) clocks used in time-domain channel sounders, yet will become vital in many
future 6G applications. This paper proposes a novel solution utilizing
precision time protocol (PTP) and periodic drift correction to achieve absolute
timing for MPCs in power delay profiles (PDPs) --captured as discrete samples
using sliding correlation channel sounders. Two RaspberryPi computers are
programmed to implement PTP over a dedicated Wi-Fi link and synchronize the TX
and RX Rubidium clocks continuously every second. This synchronization
minimizes clock drift, reducing PDP sample drift to 150 samples/hour, compared
to several thousand samples/hour without synchronization. Additionally, a
periodic drift correction algorithm is applied to eliminate PDP sample drift
and achieve sub-nanosecond timing accuracy for MPC delays. The achieved
synchronicity eliminates the need for tedious and sometimes inaccurate ray
tracing to synthesize omnidirectional PDPs from directional measurements. The
presented solution shows promise in myriad applications, including precise
position location and distributed systems that require sub-nanosecond timing
accuracy and synchronization among components.Comment: 6 pages, 7 figures, 3 tables, IEEE Global Communications Conference
(GLOBECOM) 202
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