A Note Upon Another Error Detecting Code That Is Not Proper

In this correspondence, the performance of the nonlinear error-detecting code, described in CCIR Recommendation 476-2, when used over a memoryless binary symmetric channel (BSC), is derived. From this, it is apparent that the probability of accepting an erroneous block is not a monotonic function of the bit error probability, but rather reaches a peak of 5.653 percent when the bit error probability is 11.66 percent. Consequently, this code is not proper [1]-[6].