International Journal of Computer Applications |
Foundation of Computer Science (FCS), NY, USA |
Volume 40 - Number 12 |
Year of Publication: 2012 |
Authors: Hardeep Kaur, M. L Singh |
10.5120/5014-7340 |
Hardeep Kaur, M. L Singh . Bit Error Rate Evaluation of IEEE 802.16 (WiMAX) in OFDM System. International Journal of Computer Applications. 40, 12 ( February 2012), 10-13. DOI=10.5120/5014-7340
This paper investigates several modulation techniques for IEEE 802.16 (WiMAX) based OFDM system including BPSK, QPSK, 8PSK and various levels of QAMs. The system performance is gained by dynamically choosing the modulation technique based on the channel conditions. The performance of OFDM system is accessed by using computer simulations performed using MATLAB 7.3. In this paper, transmitter and receiver models are simulated according to the parameters established by the standard, to evaluate the performance. Also, convolution coding is used to improve the system performance. Use of adaptive modulation can effectively control the BER of the transmission, as sub carriers that have a poor Eb/No (db) can be allocated a low modulation scheme such as BPSK. For good Eb/No (db), the high modulation scheme giving priority to spectral efficiency can be considered. Eb/No of the channel is estimated before the transmission. The modulation scheme is set based on the SNR of the channel.