a capacity analysis of mimo ofdma for 4g cellular system design
Orthogonal frequency division multiple access is a promising candidate for multiple access. It was originally proposed for cable TV (CATV) networks in Europe. Recently it has been considered in IEEE-802.16 Wireless Metropolitan Area Network. [2] OFDMA possess finer granularity in resource allocation. If we get channel state information at the transmitter, (CSIT); We can say that OFDMA possess higher system capacity in a single cell environment. In single cell environment, interference is white but in multicellular systems, the intercell interference must be considered and that is colored. Colored intercell interferences arise in a multicarrier system due to various reasons such as frequency selective channels, bursty transmission or non-uniform subcarrier power allocation. The absence or the imperfection of the interference knowledge will cause outage, despite CSIT. In this case, the Ergodic capacity is no longer sufficient to compare the performance of the systems. Instead, the system goodput is more meaningful for performance evaluation. In addition to intercell interference pattern, the transmit power spectrum also affects suitability of the multiple access system for multi-cell system applications. It has become very much necessary to investigate performance of various multiple access systems in a multi-cell scenario for traffics of data such as voice and packets with high data rate. Industry needs to get precise and useful insights for effective B3G or 4G cellular system designs.
mimo csit idft ofdm fft