Abstract—This paper presents an Irregular Distributed Hybrid Concatenated Differential (Ir-DHCD) coding scheme contrived for the relayaided differential decode-and-forward (DDF) cooperative system using multiple-symbol differential sphere detection (MSDSD), where no channel estimation is required. We proposed a practical design framework for a cooperative system, which is capable of performing close to the network’s corresponding non-coherent Discrete-input Continuous-output Memoryless Channel (DCMC) capacity. An adaptive-window-duration based MSDSD scheme is employed to further reduce the iterative detection complexity. Specifically, upon using the proposed near-capacity system design, the Ir-DHCD coding scheme devised becomes capable of