What Is a Wireless Transceiver?

A wireless transceiver is a central component of wireless communication systems. The quality of the wireless transceiver determines the reliability and efficiency of information delivery in the wireless system.

A wireless transceiver consists of two functional layers: a physical (PHY) layer and a media access control (MAC) layer. The PHY layer consists of an RF front end and a baseband processor. The baseband processor modulates a bitstream to a constellation symbol stream for transmission. The receiver demodulates a symbol stream to recover the transmitted signal.

The wireless transceiver RF front end adds an RF carrier to the baseband symbol stream for transmission and downconverts the received RF signal to baseband. The MAC layer provides link traffic control for the wireless transmitter to access the wireless links, avoid collisions, and optimize data throughput.

The radio front end has power and low noise amplifiers with variable gain for transmitter and receiver, respectively. The two quadrature mixers are used to upcovert the baseband signal to RF and vice versa. A zero-IF architecture is commonly employed in radio front ends. ADC and DAC implement the conversions between the analog and digital baseband signals.

The digital baseband component of a wireless transceiver consists of the following functional blocks:

• Modulation/demodulation
• Coding/decoding
• Scrambler/descrambler
• CRC

The MAC layer acts as a finite state machine. Based on the status of the channel, the received signal frames, and the frames to be transmitted, the MAC determines what and when to transmit next.

The design of a wireless transceiver requires multiple engineering disciplines to make it work. Using Model-Based Design with Simulink and Stateflow provides a seamless design workflow from the top-level system design of the interaction of wireless transceivers with the radio channels to the generation of an FPGA bitstream for SDR/FPGA prototyping.

Simulink^®, Communications Toolbox™, WLAN Toolbox™, LTE Toolbox™, 5G Toolbox™, RF Toolbox™, RF Blockset™, and Stateflow^® offer building blocks for the PHY and MAC layers of wireless transceivers, as well as different radio channel models for wireless links. For hardware implementation, Fixed-Point Designer™ and HDL Coder™ can convert the wireless transceiver model to a prototype with design space exploration. Several examples of Simulink modeling and SDR implementation on wireless transceivers are available. These examples demonstrate the process of Model-Based Design for complex wireless transceiver systems and give a quick ramp-up for wireless engineers to master this design approach.