An antenna apparatus for use in a wireless network and method of operating such an antenna apparatus are provided. The antenna apparatus has plural omnidirectional antenna elements and plural RF chains, where there are fewer RF chains than omnidirectional antenna elements. A subset of the plural omnidirectional antenna elements are coupled to the plural RF chains and sampling circuitry coupled tothe plural RF chains samples the signals received by the subset of the plural omnidirectional antenna elements. This forms part of a signal detection process in which different subsets of the plural omnidirectional antenna elements are iteratively coupled to the plural RF chains. A signal sample spatial covariance matrix for the plural omnidirectional antenna elements is constructed from the signals sampled by the sampling circuitry at each iteration and a beamforming algorithm applied to the signal sample spatial covariance matrix parameterises the signals received by the plurality of omnidirectional antenna elements.