Abstract—In this letter, we propose an efficient decoding algorithm

for turbo product codes as introduced by Pyndiah. The proposed

decoder has no performance degradation and reduces the

complexity of the original decoder by an order of magnitude. We

concentrate on extended Bose–Chaudhuri–Hocquengem codes as

the constituent row and column codes because of their already low

implementation complexity. For these component codes, we observe

that the weight and reliability factors can be fixed, and that

there is no need for normalization. Furthermore, as opposed to

previous efficient decoders, the newly proposed decoder naturally

scales with a test-pattern parameter that can change as a function

of iteration number, i.e., the efficient Chase algorithm presented

here uses conventionally ordered test patterns, and the syndromes,

even parities, and extrinsic metrics are obtained with a minimum

number of operations.