A New Technique for Incorporating RLL Properties into 5G LDPC Codes Without Additional Redundancy

In C-RAN research, different functional splits are considered for 5G mobile crosshaul networks. The typical fronthaul network based on optical fibers will be affected by the functional split. In some cases, it can be advantageous that the sequences of digital bits transmitted in fronthaul channels are runlength length limited (RLL). Therefore, in this paper a technique is presented which allows us to implement RLL properties into 5G LDPC codes specified in ETSI TS 138 212 without adding any additional redundancy and without changing the basic encoding and decoding algorithms. When compared with ordinary scrambling the new technique offers the advantage of guaranteeing the maximal runlength value.