ABSTRACT

In our present society, wireless communication has become most prevalent and mobile units (hand held devices /GSM/ Computers) are one of the most common equipments for conveying messages wirelessly. Owing to the fact that most youths in our society today on the average make use of at least one wireless device that communicate with other wireless devices via the internet, has made engineers start to think about ways to improve the quality of service (QOS), throughput, spectral efficiency, signal to noise ratio (SNR) at a minimal bit error rate (BER) of the communication link to ensure less downtime during communication. This enhancement in communication can be achieved through some modulation techniques and channel enhancement but in the course of this project I will be focusing on adaptive modulation (link adaptation) as a technique in maintaining steady low bit error rate (BER) in mobile unit (terminals). At various Signal-to-Noise ratios (SNR), we will be generating corresponding minimized Bit-error-rate’s for various modulation schemes through an Additive white Gaussian noise channel (AWGN) and compare their difference and see the uniqueness of imbibing adaptive modulation which has the ability of automatically selecting the most suitable modulation scheme based on the inherent environmental/channel conditions instead of fixed modulation.