ELEC report Group33.pdf - Group 33 Fung Chun Sing 20200230...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Group 33 Fung Chun Sing 20200230 Ho Kwan Chak 20196336 WiMAX Summary WiMAX stands for Worldwide Interoperability for Microwave Access, which is one of the 4G standard is developed in 2005. It aims at providing wireless communication at high speed and large coverage area comparing with Wi-Fi and 3G. Signals are modulated using scalable OFDMA and transmitted using MIMO. Even devices or base stations capable of WiMAX are manufactured since 2005, WiMAX market share declines sharply after LTE is released. Objective This project aims at investigating how signals modulate and transmit in WiMAX, comparing WiMAX with other wireless technology and studying the reason of why WiMAX is outcompeted. Mechanism of WiMAX Scalable OFDMA: Both uplink and downlink signals are modulated with scalable OFDMA, which can be said as a combination of OFDM and TDMA. A channel is divided into different sub- carriers which are orthogonal to each other in small bandwidth. This can minimize intersymbol interference within a sub-carrier. However frequency may offset because of Doppler Effect due to high speed movement. This leads to interference between symbols in different sub-carriers. Each sub-carriers are only assigned to one user in a timeslot. However, unlike TDMA, the time slot will be enlarge or reduce depending on the number of users subscribed and volume of data transmitted. OFDMA utilizes FFT for signal modulation and demodulation. FFT can greatly reduce the number of instructions from 𝑛 2 to n log 𝑛 . Therefore the signals can modulated and transmitted in a short time. WiMAX utilize scalable OFDMA which FFT sizes and channel spacing changes depending on the bandwidth of sub-channels and data transmitted.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern