Pragmatic Physical Layer Abstraction Method Based on Bit-LLR-Wise Exponential Effective SNR Mapping for Bit Interleaved Coded Orthogonal Frequency Division Multiplexing System

In this paper, we analyze the physical layer abstraction for bit interleaved coded orthogonal frequency division multiplexing(BIC-OFDM) system from a parallel bit channel perspective. By combining the exponential effective SNR(signal-to-noise ratio) mapping(EESM) with the maximum a posteriori(MAP) algorithm, a bit LLR(log-likelihood ratio) wise EESM(BL-EESM) method is proposed. This method can abstract the link performance with high accuracy, especially for the case when channel estimation is imperfect. Afterward, the BL-EESM method is simplified by utilizing the non-linear quantization idea, which can reduce the times of exponential operation by two orders of magnitude at wide system bandwidth, yet shows little loss in accuracy. Our proposal can be applied to both system level simulations to save the time consumption and to practical terminals to facilitate the adaptive modulation and coding(AMC) procedure, bringing about throughput improvement at low hardware cost.

Implementation of Abstract MAC Layer Under Jamming

In the past decades,with the widespread implementation of wireless networks,such as the Internet of Things,an enormous demand for designing relative algorithms for various realistic scenarios has arisen.However,with the widening of scales and deepening of network layers,it has become increasingly challenging to design such algorithms when the issues of message dissemination at high levels and the contention management at the physical layer are considered.Accordingly,the abstract medium access control(absMAC)layer,which was proposed in2009,is designed to solve this problem.Specifically,the absMAC layer consists of two basic operations for network agents:the acknowledgement operation to broadcast messages to all neighbors and the progress operation to receive messages from neighbors.The absMAC layer divides the wireless algorithm design into two independent and manageable components,i.e.,to implement the absMAC layer over a physical network and to solve higher-level problems based on the acknowledgement and progress operations provided by the absMAC layer,which makes the algorithm design easier and simpler.In this study,we consider the implementation of the absMAC layer under jamming.An efficient algorithm is proposed to implement the absMAC layer,attached with rigorous theoretical analyses and extensive simulation results.Based on the implemented absMAC layer,many high-level algorithms in non-jamming cases can be executed in a jamming network.