PPM-based Orthogonal Space-Time Coding for IR-UWB MIMO channels affected by Poisson-distributed Multipaths

In this contribution we develop a single multiple-input multiple-output impulse radio UWB (IR-UWB) transceiver for orthogonal (OPPM) data transmitted over (baseband) multipath faded MIMO channels. The proposed maximum-likelihood receiver results to be "partially coherent", because it is optimized to work without any information on the path gains, but only on the knowledge of the arrivals\´ times of the transmitted signals\´ replicas. The performance of the proposed transceiver are evaluated via three suitable versions of the Union-Chernoff bound related to several indoor and outdoor propagation scenarios, and through such limits we introduce a novel family of unitary orthogonal space-time block codes (e.g., the space-time OPPM (STOPPM) codes), that are able to attain the maximum of diversity and coding gains