OFDM is already widely used in non-cellular technologies and was considered by ETSI for UMTS in 1998
CDMA was favoured since OFDM requires large amounts of baseband processing which was not commercially viable ten years ago
OFDM advantages
* Wide channels are more resistant to fading and OFDM equalizers are much simpler to implement than CDMA
* Almost completely resistant to multi-path due to very long symbols
* Ideally suited to MIMO due to easy matching of transmit signals to the
uncorrelated RF channels
OFDM disadvantages
* Sensitive to frequency errors and phase noise due to close subcarrier spacing
* Sensitive to Doppler shift which creates interference between subcarriers
* Pure OFDM creates high PAR which is why SC-FDMA is used on UL
* More complex than CDMA for handling inter-cell interference at cell edge
