Maximum-likelihood block-size detection for MPSK signaling

In some communications systems, it is required to estimate the size of the received frame or block blindly; that is, using only the received frame. An example where such a problem arises is third-generation wideband code division multiple access universal mobile terrestrial systems (WCDMA UMTS), where it is sometimes required to perform a blind transport format detection. We propose and evaluate a novel method for block-size detection for M-ary phase-shift keying (MPSK) signaling based on the maximum-likelihood principle. Either the method we propose can be used to estimate the block size directly when the operating signal-to-noise ratio (SNR) yields a satisfactory "one-shot" detection error probability or it can be used as a good "coarse" estimate of the block size. In the latter, a good initial guess of only few potential block-size candidates is obtained instead of scanning all possible candidates and then a more accurate detection technique, however more complex, is used to narrow down the number of potential candidates to only one successful candidate