A class of high-rate N/(N + 1) low-complexity error-detecting RLL codes

We present a new methodology for the construction of high-rate channel modulation run-length-limited RLL(0,k) codes. Simple modulation encoders and decoders are constructed, with low error propagation during decoding. They combine partial error detection capability (PED) to boost the performance of a concatenated outer Error Correction Code (ECC) (Blaum, 1991). Moreover, current systems are using low redundancy ECC, and the overall rate is mainly determined by the inner modulation code rate, which critically is to be maintained high. Code rates Rc = N/(N + 1), for example, 16/17, 24/25 and higher are achievable, with efficiency exceeding 0.94 and 0.96, respectively. The proposed fixed length block decodable codes, are generalized schemes of the type N/(N + 1) (d = 0, k = [N/2]) for N ≥ 5.