“…As a novel, multiple‐input multiple‐output (MIMO) scheme, spatial modulation (SM), has emerged as an attractive candidate to achieve the spectral and energy efficiency fulfilment of the next‐generation wireless communications. As of today, the issue of widely introduced MIMO‐SM is still relevant and the construction of new classes of efficient signals is essential [8–15]. We would like to pay special attention to the fact that we consider the constellations with atypical sizes (when the size of the constellation ), as such constellations are widely used in MIMO systems, and especially in SM systems [12, 13, 15].…”