Frequency domain equalization for continuous phase modulation

Abstract

In the next generation of wireless communication systems operating at higher frequencies, the efficiency of the power amplifier becomes important to consider in long distance transmission. Power efficiency is especially crucial in situations where the base station is at remote locations with limited electricity or relies on renewable sources. Using the knowledge of the relation of input power and efficiency of the amplifier, a selection of modulation method can make possible the improvement of efficiency. Using energy efficient modulation methods from the category of continuous phase modulation leads to problems in complexity of implementation which can be mitigated using frequency domain channel equalization. In this work, such an equalizer is to be presented and its functionality verified. In order to investigate the function of the equalizer, a simulation model based on the theory presented in chapters 2, 3, 4, and 5 is constructed. The results are presented in the form of bit error rate analysis in comparison to theoretical values and results found in literature. In the comparisons, the implemented equalizer was found to function well in simple situations with some limitations in performance in more extreme circumstances. In cases with no multipath effects in the channel, the equalizer did not degrade the performance of the system. When operating in situations with multipath spreads within the theoretical limits of functionality, the equalizer managed to perform as well. When pushed beyond the limits of expected functionality, the performance suffered greatly. From the results obtained, the possibility of implementing a system using the equalizer presented may be viable in some practical cases.