Method for steering a smart antenna for a WLAN using a periodic re-scan

A client station for operating in a wireless local area network (WLAN) communication system comprising an access point, the client station comprising:

• a switched beam antenna for generating a plurality of antenna beams;
• a beam switching unit coupled to said switched beam antenna for selecting a preferred antenna beam and at least one alternate antenna beam;
• a transceiver coupled to said beam switching unit for exchanging data with the access point via the preferred antenna beam during a sustained use period during which a re-scan of the other antenna beams is not performed;
• and
• an antenna steering algorithm module for running an antenna steering algorithm, and at an end of the sustained use period and before a next sustained use period, calculating a quality metric of exchanged data for the preferred antenna beam and for each alternate antenna beam, the calculating comprising
• determining at least one link quality metric (LQM) of the exchanged data for the preferred antenna beam,
• determining a signal quality metric (SQM) of the exchanged data for the preferred antenna beam, and
• combining the at least one LQM and the SQM for calculating the quality metric for the preferred antenna beam, and
• repeating the determining and combining for calculating an alternate quality metric for each alternate antenna beam;
• said antenna steering algorithm module comparing the quality metric for the preferred antenna beam to the alternate quality metrics for the alternate antenna beams, and if the quality metric is less than at least one of the alternate quality metrics, then selecting the alternate antenna beam corresponding to the at least one alternate quality metric having a higher value to continue exchanging data with the access point within the next sustained use period.