Can Sparse Arrays Outperform Collocated Arrays for Future Wireless Communications?

Understand

Multiple-input multiple-output (MIMO) has become a key technology for contemporary wireless communication systems.

• For typical MIMO systems, antenna arrays are separated by half of the signal wavelength, which are termed collocated arrays.
• In this paper, we ask the following question: For future wireless communication systems, is it possible to achieve better performance than collocated arrays by using sparse arrays, whose element spacing is larger than half wavelength? The answer to this question is not immediately clear since while sparse arrays may achieve narrower beam for the main lobe, they also generate undesired grating lobes.
• In this paper, we show that the answer to the above question is affirmative.