The performance of very high data rate Wireless Local Area Networks (WLANs) is degraded by several problems such as long delay spread in outdoor environments or interference that may arise both from other WLANs or from other systems sharing the same band. The current standards allow the use of multiple antennas at the receiver in a Single Input Multiple Output (SIMO) configuration. Traditionally, algorithms have been applied in the frequency domain, but this paper presents a comparison of three approaches to be applied also in the time domain. It is shown that a significant uncoded Bit Error Rate (BER) performance improvement can be achieved by working before the FFT at the receiver side, especially for channels with large delay spreads.