Implementation Complexity Analysis of the Concatenated MIMO DMT-FMT Multiuser System

In this paper we address the implementation complexity of a recently proposed uplink transmission scheme. The scheme concatenates an inner filtered multitone (FMT) modulator with transmission over multiple antennas, and an outer space-time cyclically prefixed discrete multitone (ST-CP-DMT) modulator. We show that the transmitter can be implemented via a concatenation of IDoFTs and a single low rate polyphase filter bank independently of the number of transmit antennas. Further, we propose a multiuser receiver architecture that requires a single polyphase filter bank and a concatenation of DFTs, which allows for a deep complexity reduction. The multiuser receiver is capable of achieving the performance of the bank of synchronous single user receivers. Moreover we prove that the efficient implementation yields a significant reduction of the complexity for both the transmitter and the receiver.