Research On Resource Allocation Algorithms Of OFDMA Systems

With the rapid economic development, people's day-to-day communications activities have become increasingly frequent. In the future wireless communication systems, the rapid growth of mobile business has put forward higher requirements for wireless network by people. Then this has brought two most serious challenges: multipath fading channel and frequency efficiency.Because of the ability to combat multipath interference and high spectral efficiency, OFDM has become the first choice of physical layer technology in future broadband wireless access systems. OFDM is a multi-carrier modulation technology, when the signals based on OFDM transmit through wireless channel, there will be diversity effect, which means that different sub-carriers of one user may exhibit different fading condition and different users may undergo different loss for one special sub-carrier. So when some user undergo deep fading on a sub-carrier, the other users' condition may be good, then we can allocate resource according to the wireless environment dynamically so that it can boost the frequency efficiency. This is also the significance of the research on resource allocation algorithms in OFDMA systems.The development of mobile communications and radio resource management were reviewed first, and the theories of OFDM and radio resource management were presented. Then the basic concepts and principles about OFDM systems and radio resource allocation were given. Next is my main work in this paper: An OFDMA system level simulation platform was designed and developed which mainly did performance analysis of resource allocation algorithms; A new semi-static interference coordination algorithm was proposed and have been simulated and verified.The OFDMA system level simulation platform was introduced. The five main function blocks include initialization, service generate, scheduling, CQI feedback , performance statistic and the parameter of platform were presented. Meaningful conclusions were gained from the simulation of MLWDF, PF and EXP algorithms.At last interference depression in multi-cell OFDMA systems was researched and my focus is interference coordination. Based on deep investigation a semi-static interference coordination algorithm was proposed and performance evaluation was completed by simulation.