High resolution coherent radio channel measurements using direct sequence spread spectrum modulation
Gerard J. M. Janssen, J. A. M. Vriens · 2002
A measurement system for determination of the characteristics of radio paths in a multipath channel is discussed, and measurement results are presented. The measurement system uses direct-sequence spread-spectrum modulation and operates in the VHF band (30-70 MHz). A carrier, BPSK modulated with a pseudo-noise (PN) sequence at a rate of 1 Mchip/s, is used to sound the radio channel. From the coherently received in-phase and quadrature-phase signals the characteristics of the different radio paths-relative amplitude, RF-phase, and delay-time-are calculated. The accuracy of the measurement system has been determined, and is 2 dB for amplitude information, 5 degrees for the RF-phase, and 20 ns for the delay-time.>