The implementation of beamforming and spatial diversity in Orthogonal Frequency Division Multiplexing (OFDM) systems reveals challenges in terms of complexity, feedback, and scenario dependencies. In this paper we discuss the differences and limitations of OFDM transmission over scenarios with different angular spread, which can viewed clearly from the base station antenna (BSA), signals departing to or arriving from the UE appear to be spread over a range of angle and evaluate the issues arising from the implementation of beam-forming and spatial diversity in OFDM systems.
This paper describes the Matlab simulation results of receiving signals with quadrature modulation, such as OQPSK, using modified phase detector. As the result, the ber-to-snr diagrams were presented for modified and classical detector. The conclusions about its effectiveness were made. There are new methods of modulation signals that allow effective use of the frequency band, and communication systems (eg. trunking) that can effectively distribute the network traffic.