Adaptive Subband Bit and Power Loading Algorithm and its Application to OFDM Based IEEE 802 .16e

1IntroductionRecently,alarge amount of research has beenfocusedonthe high data rate transmissiontechniques over wire-less channels . One of the main requirements on thesetransmissiontechniques is the ability to combat the In-ter-Symbol Interference (ISI) ,a major problemin highdata rate transmission over multipath fading channels .OFDMis one of the promising solutions to this prob-lem1 ~3 ,12],andrecently IEEE802 .16e7]alsosuggest-ed using OFDM structure as its physical layer . Thecom…

Adaptive Subband Bit and Power Loading Algorithm and its Application to OFDM Based IEEE 802.16e

For OFDM systems with hundreds or thousands subcarriers with the adaptive bit and power loading according to each subcarrier, the signaling overhead will be awfully large. However, the adaptive bit and power loading according to "subband" is an effective solution to this problem, with which the signaling overhead is expected to be dramatically decreased at the cost of some performance loss. In this paper, based on Ref.5] but with some modification to the subband bit and power loading algorithm, we apply the algorithm to the IEEE 802.16e OFDM system. The results show that the modified subband bit and power loading algorithm can achieve better BER performance and the signaling overhead is reduced by 75% at the cost of performance loss less than 1 dB if the number of subcarriers per subband is 4 when the BER is around 10-3.