Quantifying the Diversity of OFDMA Subchannels

Orthogonal frequency division multiple access (OFDMA) has been chosen as the radio transmission technology for future 4G wireless networks. One important reason for this choice is that OFDMA offers various forms of diversity (time, frequency, space, etc). These diversity dimensions can be used to provide channels with reduced variance and hence more predictable performance. In this paper we focus on the time and frequency dimensions and propose a metric that can be used to quantify diversity. We use the proposed diversity metric to design highly diverse data subchannels and demonstrate the effectiveness of the approach through simulations. With the use of this diversity metric one can more easily design OFDMA channels because of the reduced computational time required to compare layouts.