Robust non-orthogonal space-time block codes over highly correlated channels: a generalisation

Little has so far been reported on the robustness of non-orthogonal space-time block codes (NO-STBCs) over highly correlated channels (HCC). Some of the existing NO-STBCs are indeed weak in robustness against HCC. With a view to overcoming such a limitation, a generalisation of the existing robust NO-STBCs based on a 'matrix Alamouti (MA)' structure is presented.

A robust non-orthogonal space-time block code for four transmit antennas

Several non-orthogonal space-time block coding (NO-STBC) schemes have recently been proposed to achieve full rate transmission. Some of these schemes, however, suffer from weak robustness: their channel matrices will become ill conditioned in the case of highly correlated channels (HCC). To address this issue, this paper derives a family of robust NO-STBC schemes for four Tx antennas based on the worst case of HCC. These codes turned out to be a superset of Jafarkhani's quasi-orthogonal STBC codes. A computationally affordable linear decoder is also proposed. Although these codes achieve a similar performance to the non-robust schemes under normal channel conditions, they offer a strong robustness against HCC (although possibly yielding a poorer performance). Finally, computer simulations are presented to verify the algorithm design.

Suck the living labour

The project, commissioned by Ort, Birmingham, explores geriatric vampirism. Austerity measures have indebted the young and the old through the privatisation of education and health. These age groups have been thrown into a relationship of mutual dependency and conflicting interests. As well as a new film, the exhibition featured six videos that have been outsourced using the services of sellers on the website Fiverr, ‘a place for people to share things they're willing to do for $5’. Interrogating the means of production and the meaning of work under post-Fordism, the Suck the Living Labour extends Marx’s metaphor, comparing Capital to a vampiric force that thirsts for infinite surplus.