In this paper, we propose a noncoherently non-catastrophic trellis-coded modulation scheme, in which the transmitter includes a differential encoder, a rotator, an inverse signal mapper, a convolutional encoder and a signal mapper. We present examples of the proposed scheme including MPSK (M-ary phase shift keying), QAM (quadrature-amplitude modulation), and TAPSK (twisted amplitude and phase shift keying). For trellis-coded QAM, a differential encoder with which the complexity of the proposed scheme can be reduced is proposed. Simulation results demonstrate that for noncoherent decoding, the proposed trellis-coded QAM has much better error performance than conventional trellis-coded QAM, and the proposed trellis-coded 16APSK outperforms trellis-coded 16QAM for short observation length.

In this paper, we propose a new noncoherent trellis-coded QAM (quadrature-amplitude modulation) scheme, in which a differential encoder, a rotator and an inverse signal mapper are added in front of the convolutional encoder. Trellis codes of the proposed scheme are shown to be noncoherently non-catastrophic and have better error performances than conventional trellis-coded QAM. %for short observation length. New trellis codes which, for the proposed cheme, have better bit error rates than Ungerboeck's codes are found by computer searches.

In this letter, we propose a novel bandwidth-efficient noncoherent trellis-coded MPSK scheme, in which a particularly designed differential encoder is added in front of the trellis encoder. With this differential encoder, trellis-coded MPSK proposed by Ungerboeck is no longer noncoherently catastrophic and thus achieves better error performance. Moreover, new trellis codes which, for the proposed scheme, have better bit error rates than Ungerboeck's codes are found by computer searches.