Multiuser analogue network coding with code division multiple access

An analogue network coding technique combined with asynchronous code division multiple access is proposed. A scenario is considered where there are multiple pairs of nodes with a single relay and where each pair of nodes exchange information asynchronously. With the assumption of asynchronous transmission, the analysis and the simulations show a trade-off between the number of nodes and the inter-user interference because the spreading codes are not orthogonal to each other. The analysis also shows that analogue network coding improves throughput compared with the conventional routing protocol with a large E_b/N₀, a low number of users and a large spreading factor.