Comparison of OFDM with CDMA system in wireless telecommunication for multipath delay spread

摘要

Orthogonal frequency division multiplexing (OFDM) is a parallel transmission scheme, where a high-rate serial data stream is split up into a set of low-rate sub streams, each of which is modulated on a separate subcarrier. Increasing the number of parallel transmission reduces the data rate that each individual carrier must convey and that lengthens the symbol period. This is extremely useful in environments where multipath fading is high. Most third generation mobile phone systems are using code division multiple access (CDMA) as their modulation technique. Hence, this paper compares the performance of OFDM with that of CDMA. The analysis of bit error rate (BER) performance suggests, OFDM is clearly better than CDMA. This performance is analyzed against extreme multipath delay spread conditions and with same number of users and total data transmitted. The channel effects are also same for both systems.