This paper is concerned with the design and performance of nonbinary LDPC-coded differential modulation systems. A low-complexity joint detection/decoding method for noncoherent demodulation is proposed, in which the hard-message-passing strategy is used for a joint factor graph. It combines trellis-based differential detection aided with channel prediction and the reliability-based decoding of nonbinary LDPC codes introduced in [1]. The Max-Log-MAP algorithm with soft-in hard-out is used for the differential detection. Simulation results show that the proposed method can offer good performances with a greatly reduced complexity.

SystemC, as a C++-based hardware description language, is used for system architecture design, large digital hardware, software, and their interaction. Its extension, SystemC-AMS, provides the capability of abstract modeling to deliver analog system-level simulation of “real-time” application scenarios. SystemC and SystemC-AMS help designers to analyze a whole mixed-signal system and further guide the circuit design to reduce the design cost. This paper presents SystemC (2.2.0) and SystemC-AMS (1.0 Beta2) modeling of a near-field communication (NFC) system working in passive mode, based on the proximity contactless identification cards ISO/IEC 14443 international standard. The NFC transceiver system includes reader and card analog blocks, digital blocks, and antennas. Problems caused by realistic imperfections are considered, simulated, and then solved by modifying the design at a system level, which is significant to high-level modeling. Systematic simulation is given to prove SystemC/SystemC-AMS is an accurate and efficient tool to model a heterogeneous mixed-signal system in an early-design stage.