OFDM for Underwater Acoustic Communications

Chapter 13Co-located MIMO OFDM

Chapters 9–12 presented receiver designs for single-transmitter OFDM systems in different scenarios. From this chapter to Chapter 15, we will look into receiver designs for multi-input multi-output (MIMO) systems, where multiple transmitters could be co-located or spatially distributed.

• Chapter 13: Co-located MIMO OFDM. This chapter focuses on the MIMO-OFDM reception for a MIMO system with co-located transmitters, in which, as illustrated in Figure 13.1, multiple parallel data streams are used to increase the bandwidth efficiency. The signals from co-located transmitters are quasi-synchronized at the receiver and experience similar Doppler scaling effects.
• Chapter 14: Distributed MIMO OFDM. This chapter considers a particular scenario with multiple geometrically distributed users, where the moving velocity could be drastically different from user to user. The signals from different users are assumed to be quasi-synchronized at the receiver, and the focus is on how to deal with different moving velocities of users.
• Chapter 15: Asynchronous multiuser OFDM. This chapter looks into a communication system with multiple geometrically distributed users in which signals from users are misaligned at the receiver but have a similar Doppler effect. It will present an OFDM receiver for asynchronous multiuser reception.

Figure 13.1 Illustration of a co-located ...