MISO model for improving performance of OFDM-CDMA system with pilot tone

In this paper, MISO OFDM-CDMA downlink scheme is proposed as a solution for improving performance of the OFDM-CDMA downlink system with pilot tone and threshold detection combining (optimum TDC). Space-time block coding (STBC) applied to two, three and four transmit antennas is implemented in the proposed scheme. Original simulation model is developed for obtaining bit error rate (BER) performance in the case of Ricean frequency selective fading. Evidently better BER performance can be achieved with proposed system, while maintaining the same spectrum efficiency. Besides that, spectrum efficiency can be improved with the proposed system, i.e. proposed scheme with decreased number of subcarriers retains better BER performance. Also, implementation of very complex equalization technique such as optimum TDC is avoided. Instead of that orthogonal restoring combining (ORC), as a considerably simpler equalization technique is implemented.