Union Bound Analysis of Concatenated Twist Hadamard Codes

Concatenated twist Hadamard code (CTwHQ is a new class of low-rate error-correcting codes designed based on two single parity check constraints in bi-orthogonal Hadamard codes, which can present good error floor performance with low decoding complexity. To analyze CTwHC from a theoretical perspective, a simple recursive technique based on trellis structure is proposed to achieve union bound of CTwHC in this paper.