Wireless Transceiver Architecture

1 The Digital Communications Point of View

When detailing how to dimension a transceiver, it can seem natural to first clarify what is expected from such a system. This means understanding both the minimum set of functions that need to be implemented in a transceiver line-up as well as the minimum performance expected from them. In practice, these requirements come from different topics which can be sorted into three groups. We can indeed refer to the signal processing associated with the modulations encountered in digital communications, to the physics of the medium used for the propagation of the information, and to the organization of wireless networks when considering a transceiver that belongs to such system, or alternatively its coexistence with such systems.

The last two topics are discussed in Chapter 2 and Chapter 3 respectively, while this chapter focuses on the consequences for transceiver architectures of the signal processing associated with the digital communications. In that perspective, a first set of functions to be embedded in such a system can be derived from the inspection of the relationship that holds between the modulating waveforms used in this area and the corresponding modulated RF signals to be propagated in the channel medium.

As a side effect, this approach enables us to understand how information that needs a complex baseband modulating signal to be represented can be carried by a simple real valued RF signal, thus leading to the key concept of ...