Channel resolvability codes based on concatenation and sparse linear encoding

A concatenation of two encoders is used to construct channel resolvability codes. The code of the first encoder has large minimum distance and the second encoder is linear and has a sparse generator matrix. If the first encoder has encoding complexity O(n) or O(n log n), where n is the length of the codewords, an overall encoding complexity O(n log n) can be achieved. One can tune the sparsity to trade off the complexity of the second encoder against the minimum distance requirement of the first code, and to trade off the complexity of one of the encoders and the informational divergence scaling.