Corrections to “Error Vector Magnitude as a Performance Measure for Advanced Modulation Formats” [Jan 1, 2012 61-63]

In the above titled paper (ibid., vol. 24, no. 1, pp. 61-63, Jan. 1, 2012), equation (4) contains an error. The corrected equation is presented here. Additionally, the paper should include an Appendix, which is presented here.