Link capacity analysis for virtual antenna arrays

Abstract

The previously introduced concept of virtual antenna arrays (VAA) promises a significant increase in link and system capacity. These therefore constitute a promising candidate for ad-hoc oriented 4G networks. VAA successfully emulates a multiple-input-multiple-output (MIMO) transmission channel to which space-time codes (STC) can be applied. The realisation of VAA is accomplished by letting spatially close mobile terminals communicate with each other, which overcomes the disadvantage of having only one receiving antenna in a mobile handset. The thus created ad-hoc network represents a general form of MIMO channels for which a new approach to link capacity calculation is required. The work presented establishes some fundamental tenets for the calculation of link capacity in the Shannon sense to ad-hoc networks, such as VAA. It shows that the capacity drastically increases over a network where each terminal maintains a single link to the base station. The results are somewhat preliminary since VAA constitutes only a minor subset of possible ad-hoc network configurations.