Design and implementation of an adaptive coding and modulation system for microwave radio transmission in mobile backhaul networks

The design of an adaptive coding and modulation (ACM) system for microwave radio transmission in mobile backhaul networks must comply with a number of application related constraints. The system gain should be maximized within the block length limits imposed by the maximum admissible transmission delay. The microwave channel characteristics require that the ACM system possess a high flexibility in terms of code rates and modulation alphabet. This paper describes the industrial application of a pragmatic ACM system, starting from system design down to architectural design and implementation in FPGA and ASIC technologies. The performance of the implemented scheme is compared against traditional codes in simulations and in a real-time radio link FPGA-based prototype.