Explain MIMO and its impact on wireless performance.

• A. MIMO uses a single antenna to simplify design and reduce cost.
• B. Multiple Input, Multiple Output uses multiple antennas to increase data rate and link reliability through spatial multiplexing and diversity.
• C. MIMO reduces the data rate to improve reliability.
• D. MIMO is a technique to encrypt wireless transmissions.

Answer: (B)

MIMO uses multiple antennas at both the transmitter and receiver to exploit multipath signals and improve wireless performance. It boosts data rates through spatial multiplexing, which sends several independent data streams over different spatial paths, provided the channel supports it. It also enhances reliability via spatial diversity, using multiple paths to carry information so the link remains strong even if some paths fade. Together, these mechanisms raise spectral efficiency and can extend usable range in real-world environments with reflections and scattering. The other statements miss the mark: using a single antenna doesn’t leverage MIMO, reducing data rate isn’t what MIMO does, and encryption isn’t the purpose of MIMO.