Signals and Systems of 3 Familiar Devices
The structure of a smartphone is similar, but a smartphone also has a global positioning receiver (GPS) and multiband radio blocks that send and receive continuous-time signals from base stations (antenna sites) of a cellular network.
The GPS receiver acquires signals from multiple satellites to get your latitude and longitude. The primary purpose of the GPS in most smartphones is to provide location information when placing an emergency call (E911).
Four antennas are shown, but only a single multiband antenna is employed in most models, so only a single antenna structure is really needed.
The multiband cellular radio subsystem is thick with signals and systems. The multiband digital communications transmitter (tx) and receiver (rx) allows the smartphone to be backward compatible with older technologies as well as with the newest high-speed wireless data technologies. This transmitter and receiver enable the product to operate throughout the world. A smartphone is overflowing with signals and systems examples!