OFDMA is the preferred multiple access technique to provide high data rate services in mobile environment due its resilience against multipath propagation impairment and flexibility to provide multi-rate data services. However, it also has issue with susceptibility to ICI (inter-carrier interference) caused by frequency offset and Doppler spread due to mobility. Thus, OFDMA with certain number of sub-carriers will only be optimum over a certain range of mobility. Recently, a VSB-OFDMA (variable sub-carrier OFDMA), system has been proposed to relax the effect of ICI. Although it suffers from non-orthogonality caused by different sub-carrier sizes, as ICI is inversely proportional to the sub-carrier bandwidth, it rakes in benefit from reduced ICI in mix-mobility environment. It has been shown to produce higher system capacity under mix-mobility environment. In this paper we have performed comparison based on computer simulation to gauge the advantage offered by VSB-OFDMA in terms of BER.