Guest Editorial Recent Advances in Capacity Approaching Codes

The papers in this special issue address the topic of capacity approaching codes. This issue reflects a further shift of interest in coding theory research, this time toward polar codes, a new class of capacity achieving codes introduced in 2008. Of the 17 papers appearing in this issue, 9 are devoted to various aspects of polar codes, with 6 papers devoted to LDPC codes, including 3 on spatially coupled (convolutional) LDPC codes, and 2 on other coding topics.