Measurement and evaluation of multi-antenna handsets in indoor mobile communication

A method for evaluating antenna diversity systems is presented with an example of a handset using up to four antennas in indoor mobile communication. The method includes a "two-at-a-time" measurement test setup that uses maximum likelihood estimation of the covariance matrix and compensation for the imperfect match, which typically occurs during the design and evaluation process for compact antennas. The diversity performance of the antenna system can be presented as an effective order of diversity, which is the equivalent number of equal power, uncorrelated diversity branches for the same diversity gain at a given probability.