Advantages of SDR | Disadvantages of SDR, Software Defined Radio
This page covers advantages and disadvantages of SDR (Software Defined Radio). It mentions benefits or advantages of SDR and drawbacks or disadvantages of SDR.
What is SDR?
The term SDR stands for Software defined radio. It is programmable transceiver which supports various wireless technologies without the need to update hardware. It is required to have easy migration during product developments from one standard based device to the other. Examples of such standards include LTE to LTE-advanced or 4G to 5G or WiFi-11ac to WiFi-11ax and so on. SDR deals with software defined wireless communication protocols (e.g. PHY, MAC) rather than hardware based solutions.
There are various approaches to design and implement SDR modules on hardware platforms viz. GPP (General Purpose Processor), DSP (Digital Signal Processor) and FPGA (Field Programmable Gate Array) etc. Following table mentions comparison between different SDR design methods based on various parameters such as power efficiency, throughput, cost, execution etc. This table helps in selecting appropriate method for your SDR designs.
|Computation||Fixed Arithmetic Engine||Fixed Arithmetic Engine||User Configurable Logic|
|Input/Output||Dedicated ports||Dedicated ports||User Configurable Ports|
|Execution||Sequential||Partially Parallel||Highly Parallel|
The figure depicts SDR architecture of transmitter and receiver modules. SDR transmitter consists of baseband modules such as FEC encoder, modulation, IFFT etc. The digital IF is converted to analog IF using DAC (D/A converter). Analog IF is converted to analog RF and is being amplified using Power Amplifier (PA) before transmission by antenna into the air. The SDR receiver usually consists of PA, tuner, ADC, digital front end modules (DDC, LPF) and signal processing modules (FFT, demodulator, FEC decoder etc.).
As shown, entire chain involving digital front end, RF front end and signal processing algorithms are implemented using SDR approach. Refer article on basics of SDR >>.
Benefits or advantages of SDR
Following are the benefits or advantages of SDR:
➨SDR based prototypes help researchers and developers during realization of 3GPP or IEEE standard based communication protocols. SDR mainly used for physical layer and RF implementation as per WiFi (802.11b/a/g/n/ac/ax), Bluetooth, Zigbee, Zwave, WiMAX, LTE, 5G, 6G standards etc. Hence time to market can be met.
➨It offers flexible, reconfigurable and programmable framework. This helps to meet varied needs of different users in terms of hardware specifications. The same SDR hardware can be used for various radio system architectures.
➨SDR hardware prototypes are ready to adapt any future upgrades and protocols.
➨As same prototype hardware can be used, SDR approach leads to less development costs.
➨It helps in selection of RF carrier frequency, modulation type, FEC techniques, sampling frequency as per system requirements.
➨It offers high level of performance which can be tuned by software.
Drawbacks or disadvantages of SDR
Following are the challenges or drawbacks or disadvantages of SDR commonly found during SDR implementations.
➨Poor dynamic range in some SDR prototype designs.
➨It is difficult to write software to support different target platforms.
➨SDR architecture consists of analog RF front end and digital front end. Hence it is challenging to implement interfacing between analog and digital modules or blocks.
➨ADC limits maximum frequency to be used by digital part of SDR (Software Defined Radio).
➨SDR development requires software and hardware engineers.
➨For few simple radio system designs, SDR platform may be very expensive to afford.