Analisis Optimalisasi Parameter Kinerja Sistem CDMA Dengan Menggunakan Kanal Propagasi Gelombang Radio Empiris

A study has been made on the analysis of optimizing the performance parameters of the CDMA system using the empirical radio wave propagation channel. For the construction of this analysis have been developed modeling of the transmission system of two Base transceiver station (BTS) to three and four base transceiver stations to serve the Mobile Station (MS). Development of a model of the transmission system from two to three and four base transceiver stations require the development of soft handover algorithm that can be handle from two to four base transceiver stations. By choosing the empirical radio propagation channel as a transmitting channel that connects the base transceiver stations with MS, then has obtained improvement of performance parameters of cdma system against a change of height of BTS and MS antena and also against a change of the parameter value of hysteresis add. System performance parameters are defined as objects of observation in this study is a call drop rate, decrease rate of radio link, average size of active set and handover rate. Furthermore, by utilizing locally optimal algorithm, then both of the system performance parameters, namely the average size of the active set and handover rate, still can be optimized with the same of radio link quality. The results of the simulation data analysis showed that the change in height of BTS antennas and antenna MS contribute to the improvement of the reception of the signal power level, so as to reduce the average rate of drop call , improve the quality of radio links and increase the average size of the active set. In terms of changes in the value of hysteresis add contribute to the increase in the average size of the active set. While the handover rate is dominated by fluctuations in the size of the active set in the system. Application of locally optimal algorithms on the threshold hysteresis algorithm gives a reduction in the average size of the active set and handover rate, thus increasing the efficiency of the use of radio channels and save the connection costs. Based on the comparison of the performance of the models of the empirical radio wave propagation against the performance of the soft handover parameters, then the hata propagation model gives a greater contribution to the improvement of system performance parameters compared to the okumura propagation model and the lee propagation model. Therefore, hata propagation model can be chosen as a more appropriate of propagation model based on the input parameters of the system have been determined .