Extended tail-biting schemes for turbo codes

In this letter, we investigate the problem of using tailbiting recursive systematic convolutional (RSC) codes in turbo codes. Tailbiting is not always possible for a given RSC code with fixed length. We propose an extended tailbiting method for RSC codes and compare it with another extension method proposed by Van Stralen, et al. (IEE Electron. Lett., vol. 35, pp. 1461-1462, 1999). Several schemes using these extended tailbiting RSC codes in turbo code systems are developed and compared.