Certain investigations in cross layer techniques for downlink scheduling in wireless networks

Abstract

Recent research in cross layer design yields more number of integration techniques with physical layer to maintain a strategic distance from the short comings of Open System Interconnection (OSI) layer and to guarantee the Quality of Service (QoS) in heterogeneous systems. Among those integration techniques, the Rate-Adaptive Modulation and coding draws more attention of the researchers in the current scenario. The main objective of the thesis is divided into four contributions. First, an improved Adaptive Modulation and Coding (AMC) scheme has been proposed by consolidating slight modifications of the existing AMC scheme. The main objective of the cross layer approach in AMC is to improve the spectral efficiency of the transmission framework despite the fact that the channels are time varying in nature. In the existing AMC conspire, the wellknown modulation techniques like Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK) and Quadrature Amplitude Modulation (QAM) with different rates have been employed. An improved AMC has been proposed by including the Gaussian Minimum Shift Keying (GMSK) modulation that improves the overall spectral efficiency of the system. Numerical outcomes demonstrate that the proposed AMC has incredible spectral efficiency when contrasted with the existing modes. The AMC works well when there is no over flow in the queuing at the buffer. If the overflow occurs in the queuing, then the AMC has to be designed along with queuing to reduce the Packet Dropping Probability (PDP) and Packet Error Rate(PER) in order to achieve the desired throughput and spectral efficiency. newline