The ATM Wireless Access (AWA) System allows portable terminals such as notebook PCs to provide up to 10Mbits/s to each user. AWA will be one of the last hops of the fiber system; it seamlessly provides wireless terminals with most of the services available in the fiber system. A prototype is developed to confirm system realization and the technical feasibility of the radio transmission rate of 80 Mbit/s, the highest yet reported in wireless access systems, by employing ATM technology to support multimedia communication with different communication quality requirements. The prototype uses TDMA as the multiple access method. This paper proposes the system concept and technical issues of the AWA system. The design and performance of the AWA prototype are clarified. It is confirmed that the target performance of the prototype can be achieved and technical issues are feasible.

A new practical method of predicting outage probability caused by multipath fading in the presence of thermal noise and interference has been presented for multi-level digital radio systems. First, the linear amplitude dispersion (LAD) method using the waveform factor was derived. Outage probability due to ISI can be easily predicted for any system and any paths using this method. The validity of the method was confirmed in field experiments. Synergistic effects of noise and interference on outage were also discussed. Closed form expressions to evaluate the synergistic effects have been derived and the results were compared with those predicted by the power sum method. Both sets of results agree well. Analysis proved that synergistic effects depend only on the difference between flat fading margin and dispersive fading margin, and are independent of modulation scheme or path characteristics. The method presented here can be applied in a unified way to various systems having different modulation scheme, symbol rate, spectrum shaping, etc.

This paper describes a fiber-optic microcell radio system with a spectral delivery switch to meet traffic demands. Optical link performance is discussed from the view points of link loss and noise figure aimed at system design. The theoretical carrier-to-noise ratio (CNR) performance is shown as a function of the input electrical power of the laser and the received optical power. Improvement of dynamic range defined by both CNR and intermodulation distortion is proposed by using the frequency modulation (FM) technique. The experimental results using the proposed technique indicate that the performance is much better than that of conventional methods. Moreover, economical diversity planning delivery methods over fibers are presented. This strategy will provide more cost effective and flexible networks.