Coverage planning in 3G multimedia networks based on Walsh coding

Capacity in Wideband Code Multiple Access (WCDMA) systems is interference limited, it is also strongly linked with coverage. The greater the level of influx of users within the cell, the higher the interference and hence the lower the cell coverage becomes and vice versa. This is called Cell Breathing. In this paper a Walsh coding is used as a precoding stage to the Multiple-Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system. The results of this work are compared with a conventional work that is based on convolutional coding. This is in order to check its fitness to the current system structure and the enhancement of the E_b/N_o, which will directly result in a better cell coverage and continued reliable services for the area of the cell as the load increases. Based on the simulation results, Walsh coding shows a slight improvement of complemetary cumulative distribution function (CCDF). As a consiquence, the MIMO-OFDM systems´ performance is improved comparing with the covolutionally coded MIMO-OFDM system. Thus, not only the Peak-to-Average Power Ratio (PAPR) is saved, but also the frequency spectrum efficiency is improved.