Future broadband wireless communication systems will need to use advanced technologies to effectively deal with the detrimental time dispersive mobile radio environment. Single carrier frequency domain equalization (SC-FDE) has been recently receiving much attention for its ability to perform as well as orthogonal frequency-division multiplexing (OFDM) and sometimes even better while having almost the same signal processing complexity as OFDM. Because of its single carrier transmission, FDE has lower peak-to-average power ratio (PAPR) and reduced sensitivity to carrier frequency offsets (CFO) than OFDM....[ Read more ]

Future broadband wireless communication systems will need to use advanced technologies to effectively deal with the detrimental time dispersive mobile radio environment. Single carrier frequency domain equalization (SC-FDE) has been recently receiving much attention for its ability to perform as well as orthogonal frequency-division multiplexing (OFDM) and sometimes even better while having almost the same signal processing complexity as OFDM. Because of its single carrier transmission, FDE has lower peak-to-average power ratio (PAPR) and reduced sensitivity to carrier frequency offsets (CFO) than OFDM.

In this thesis, we investigate the use of SC-FDE for ubiquitous broadband wireless communications from two aspects: System design and performance analysis. From the system design point of view, we first investigate the design of frequency domain equalization with decision feedback processing (FD-DFE) in the systems with multiple transmit antennas to effectively achieve both spatial and frequency diversities. We also propose the design of frequency domain equalization with noise prediction (FDE-NP), which has lower complexity and achieves better performance and complexity trade-off than FD-DFE. The basic FDE-NP structure is further applied in multi-input and multi-output (MIMO) systems to achieve multiplexing gain and/or perform multiple access over frequency selective channels. It is also shown that the FDE-NP MIMO scheme can be combined with successive interference cancellation (SIC) to detect different transmit streams sequentially. We combine the Tomlinson-Harashima precoding (THP) with MIMO-FDE and propose a joint transmit-receiver FDE scheme, which does not have the error propagation problem as in FD-DFE and FDE-NP. In addition, we shall investigate the design of frequency domain pre-equalization (FDPE) in broadcast MIMO channels. By combining FDPE with parallel and successive transmit precoding, the broadcast MIMO transmission can be achieved over frequency selective channels with limited processing at the multiple receivers.

From the performance analysis point of view, we will investigate the performance analysis of FD-DFE in a general single-input and single output (SISO) system. We propose a design approach that leads to a simple minimum mean-square error (MMSE) expression. The derived MMSE can be related to the symbol or bit error probability using a modified Chernoff bound (MCB). It is shown that MCB is much tighter than the conventional bound, and is very close to the true simulated results at reasonable signal-to-noise ratio (SNR) values. The analysis approach is further extended in the analysis of FDE MIMO systems. It is also shown that the same approach can be applied as an excellent performance approximation to the proposed THP-FDE MIMO systems. Finally, in the performance analysis of the proposed FDPE scheme, which could be seen as a transmit MIMO processing in the downlink broadcast channel, we show that the proposed FDPE scheme is a dual structure of FD-DFE, which could be seen as a receive MIMO processing in the uplink multiple access channel. By considering the uplink and downlink MMSE relationship, the average BER in the downlink (uplink) transmission can be approximated from the knowledge of the MMSE in the uplink (downlink) transmission.