Space–time spreading–multiplexing for MIMO wireless communication systems using the PARATUCK-2 tensor model

Unified tensor model for space-frequency spreading-multiplexing (SFSM) MIMO communication systems

“…Note that the contracted received signal tensorȲ ∈ C I×N×P given by (19) follows a PARAFAC model with matrix factors (H( ), S, C). In fact, models (17) and (19) for the transmitted and received signal tensors, respectively, differ only in their first-mode matrix factors, which are related by (20).…”

“…In fact, models (17) and (19) for the transmitted and received signal tensors, respectively, differ only in their first-mode matrix factors, which are related by (20).…”

“…In the multiuser case, the total number of transmitted data streams (summed over all the users) is equal to R = R (1) + · · · + R (Q) , where R (q) denotes the number of space-frequency spread data streams transmitted by the qth user. With these definitions, the received signal model (19) can be rewritten as follows…”

“…Recently, tensor modeling has successfully been applied to the design of MIMO transceivers based on spatial multiplexing and/or space-time coding [13][14][15][16][17][18][19]. Relying on the use of spreading codes, the common feature of these works is the fact that the received signal can be modeled as a third-order tensor, the dimensions of which are associated with space, time, and code diversities [20].…”

“…The multiuser downlink case is treated in [16]. More general tensor-based space-time spreading and multiplexing structures were also proposed relying on the constrained factor (CONFAC) model [17,18] and on PARATUCK-type models [19,23].…”