Measurement, modeling, and OFDM synchronization for the wideband mobile-to-mobile channel.

摘要

Wireless communication services tend towards "anywhere" and "everywhere" capabilities. Many of the available services require a stationary base station to provide links between mobile stations. Wideband mobile-to-mobile (MTM) communications might allow future digital broadband mobile services with a reduced infrastructure investment. There is also a growing interest from the military in wideband MTM communications for tactical applications. Another one of these conceived services is dedicated short range communications (DSRC), which is a short to medium range service that supports both Public Safety and Private operations in roadside to vehicle and vehicle-to-vehicle communication environments. The DSRC standard uses orthogonal frequency division multiplexing (OFDM).; Wideband measurements of the mobile-to-mobile channel, especially of the harshest channels, are necessary for proper design and certification testing of mobile-to-mobile communications systems. A complete measurement implies that the Doppler and delay characteristics are measured jointly. However, such measurements have not previously been published.; The main objective of the proposed research is to develop channel models for specific scenarios from data obtained in a wideband mobile-to-mobile measurement campaign in the 5.9 GHz frequency band. For this purpose we developed a channel sound ing system including a novel combined waveform. In order to quantify and qualify either the recorded channel or the proposed generated channel, we developed a simulation test-bed that includes all the characteristics of the proposed DSRC standard. The resulting channel models needed to comply with the specifications required by hardware channel emulators or software channel simulators. From the obtained models, we selected one to be included in the IEEE 802.11p standard certification test. To further aid in the development of software radio based receivers, we also developed an OFDM synchronization algorithm to analyze and compensate synchronization errors produced by inaccessible system clocks.