27/08/2019: ThS. Ngô Khắc Hoàng (Univ. Paris-Saclay, France), Constellation Design for Non-coherent Communications in SIMO Block-Fading Channel

The communication without a priori channel state information is called non-coherent communication. For the non-coherent Rayleigh block-fading channel, it was shown that the optimal signaling is to encode information in the subspace of the signal matrix in the space-time domain. Therefore, a constellation for this channel can be designed as a collection of subspaces. Such constellations belong to the Grassmann manifold, which is the space of subspaces, and thus are called Grassmannian constellations. In this talk, we focus on the single-transmit-antenna (SIMO) case. We first present the optimality of Grassmannian signaling and the constellation design criteria. Then, we introduce a practical Grassmannian constellation so-called the cube-split constellation. This constellation is constructed with a structure that facilitates low-complexity symbol decoder and bit log-likelihood computation while achieving a high packing efficiency. Numerical results show that the performance of the cube-split constellation is close to that of a numerically optimized constellation, and better than other structured constellations. It also outperforms a coherent pilot-based scheme in the case of short coherence time and large constellation size.

Speaker: ThS. Ngô Khắc Hoàng, Univ. Paris-Saclay

Time: 15:30, Tuesday, August 27, 2019

Venue: G2-315, 144 Xuan Thuy, Cau Giay, Hanoi