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Theory

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Simulation

Posttest

References

Contributors

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Spatial Multiplexing

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After pre-processing and post-processing using SVD, what happens to the MIMO system?

a: It works as an effective combining technique providing diversity gain Explanation

Explanation

b: It decomposes the channel into rank(H) parallel independent channels Explanation

Explanation

c: Since it involves multiplying input and output by a weight vector, it leads to increased power (array gain) Explanation

Explanation

d: None of the above Explanation

Explanation

Given H = [[1, 1], [1, -1]] × [[5, 0, 0], [0, 3, 0]] × [[1, 1, 0], [1, -1, 4], [2, -2, 1]], how many independent parallel streams can be formed?

a: 1 Explanation

Explanation

b: 2 Explanation

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c: 3 Explanation

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d: Cannot be determined from given info Explanation

Explanation

Find the SVD of the matrix [[3, 0], [4, 5]].

a: U = [[0.6, -0.8], [0.8, 0.6]], Σ = [[5, 0], [0, 3]], Vᵀ = [[1, 0], [0, 1]] Explanation

Explanation

b: U = [[0.6, 0.8], [-0.8, 0.6]], Σ = [[6, 0], [0, 2]], Vᵀ = I Explanation

Explanation

c: Correct SVD values as computed Explanation

Explanation

d: None of the above Explanation

Explanation

Find the capacity of the above-given channel given that B = 10 Hz, the total power available at the transmitter is 10 dB, and the noise variance is 1.

a: 20 bps Explanation

Explanation

b: 33.22 bps Explanation

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c: 40 bps Explanation

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d: 15 bps Explanation

Explanation

In spatial multiplexing, what happens when the number of transmit antennas exceeds the number of receive antennas?

a: All transmitted streams can always be reliably separated Explanation

Explanation

b: System capacity always increases linearly Explanation

Explanation

c: Some spatial streams may interfere with each other, degrading performance Explanation

Explanation

d: The receiver can ignore extra streams without any performance loss Explanation

Explanation

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