Flexible and scalable front-end tuner for software defined radio: Page 4 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.

Figure 5: MAX2175 World Band Radio receiver.

The MAX2175 provides a buffered differential output of the reference frequency to support multi-tuner systems. The design integrates all key blocks, enabling low-power, tuner-on-board designs with advanced baseband solutions. The tuner includes digital filtering to minimize the MIPS required in the baseband processor to demodulate the desired channel. The resulting I-channel and Q-channel data words are transferred to the baseband via an industry standard I2S digital interface. The MAX2175 IC is available in a 48-pin TQFN package (7- x 7-mm) with an exposed pad. Electrical performance is guaranteed over the extended -40°C to+85°C temperature range.

Conclusion

We have reviewed, at a high level the ideal software defined radio architecture. We discussed the system partitioning steps necessary to enable software control of the baseband signal processing, such that a wide range of radio standards can be received by a single radio platform.

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