The Research of ST-OFDM in Physical Layer of IEEE 802.16a

This paper briefly introduces one of the three physical layer implementations of IEEE 802.16a~1],WirelessMAN-OFDM PHY.Based on the implementation,the combination of Orthogonal Frequency Division Multiplexing(OFDM)and Space-Time Coding(STC)which is briefly called ST-OFDM in IEEE 802.16a,is investigated under thechannel provided in Ref.2].Especially,this paper is focused on the influence of the optimal decision threshold on the sys-tern Bit-Error-Rate(BER)performance based on unequal probabilities of sources.The simulations show that when Signal-Noise-Ratio(SNR)is low the optimal decision threshold is obviously superior to the usual one;when SNR is high to someextent,such as 10 dB for 4QAM and 16 dB for 16QAM,we can use the usual decision threshold instead of the optimal

The Research of ST-OFDM in Physical Layer of IEEE 802.16a

This paper briefly introduces one of the three physical layer implementations of IEEE 802.16a1], Wireless MAN-OFDM PHY. Based on the implementation, the combination of Orthogonal Frequency Division Multiplexing (OFDM) and Space-Time Coding ( STC ) which is briefly called ST-OFDM in IEEE 802.16a, is investigated under the channel provided in Ref . 2 ]. Especially, this paper is focused on the influence of the optimal decision threshold on the system Bit-Error-Rate ( BER ) performance based on unequal probabilities of sources. The simulations show that when SignalNoise-Ratio ( SNR ) is low the optimal decision threshold is obviously superior to the usual one; when SNR is high to some extent, such as 10 dB for 4QAM and 16 dB for 16QAM, we can use the usual decision threshold instead of the optimal one .