An antenna apparatus for use in a wireless network and method of operating such an antenna apparatus are provided. The antenna apparatus has omnidirectional antenna elements and RF chains, where there are fewer RF chains than omnidirectional antenna elements. A subset of the omnidirectional antenna elements are coupled to the RF chains and sampling circuitry coupled to the RF chains samples the signals received by the subset of the omnidirectional antenna elements. This forms part of a signal detection process in which different subsets of the omnidirectional antenna elements are iteratively coupled to the RF chains. A signal sample spatial covariance matrix for the 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 parameterizes the signals received by the omnidirectional antenna elements.