Flexible and scalable front-end tuner for software defined radio: Page 2 of 5

April 11, 2017 //By Nazzareno Rossetti, Kishore Racherla, Adam Heiberg
Traditional radio receivers require as many radio receiver chips as there are standards. In contrast, Software Defined Radio (SDR) architectures perform the baseband processing using software, enabling reception of a wide range of radio standards with a single radio platform. This article discusses different ways to handle the SDR baseband processing and proposes a cost effective, flexible and scalable implementation that best actualizes the potential of SDR.

Heavy integration approach to SDR

Although the baseband processing may be implemented in software with SDR, the software still needs to run on some hardware platform. One implementation, outlined in Figure 2, places two baseband signal processing cores on the same chip, each with its own front-end, to handle AM and FM. This architecture does not fully lend itself to the SDR strategy, since more standards exist. The demodulation algorithm is also hard wired inside the baseband signal processing section, hence there is no possibility for adapting to a variety of techniques and evolving standards as desired for an ideal SDR.

Figure 2: Highly integrated approach to SDR.

World Band Radio

In order to fully achieve the flexibility envisioned by SDR, a more flexible architecture is needed. A stand-alone front-end tuner (Figure 3) capable of implementing all primary analog and digital radio standards (Table 1), dubbed World Band Radio (WBR), has been proposed by Maxim Integrated. This flexible tuner, paired with an SDR backend, enables a single radio platform to receive all global radio standards.

Table 1: Radio standards.

Figure 3: World band radio IC.

Design category: