Multiple-Access Capabilities of a Common Gateway

This paper is concerned with the performance analysis
of a dual-hop random access network where a single gateway
is employed to connect a random number of independent users
which are hidden from their destination(s). The gateway is an
amplify and forward relay, and is the only mean to connect users
to their destinations. We develop accurate mathematical models
for the multiple access interference which take into account, in
addition to the distribution of the number of active users and
their random locations, the effects of fading and thermal noise
at both the relay and destinations. A new unified mathematical
method is developed, which leads to the derivation of new
analytical expressions for the overall spectral-efficiency of the
dual-hop random access network over Rayleigh and Nakagamim
fading channels. The accuracy of the new mathematical results
is confirmed by Monte Carlo simulation. The results of this paper
can be used to estimate the aggregate throughput of a dual-hop
system employing the slotted-Aloha type protocols.