EC4011D: Lecture 12

Which of the following sequence of symbols provides time diversity when sending symbols A, B, C, D, E, F, G, H... over a fading channel?

• A, B, C, D, E, F, G, H...

• A, A, B, B, C, C, D, D, E, E, F, F, G, G, H, H...

Which of the following sequence of symbols provides the most time diversity when sending symbols A, B, C, D, E, F, G, H... over a fading channel?

• A, B, C, D, E, F, G, H...

• A, A, B, B, C, C, D, D, E, E, F, F, G, G, H, H...

• A, A, A, B, B, B, C, C, C, D, D, D, E, E, E, F, F, F, G, G, G, H, H, H...

Which of the following sequence of symbols provides the most time diversity when sending symbols A, B, C, D, E, F, G, H... over a fading channel?

• A, B, C, D, E, F, G, H...

• A, A, B, B, C, C, D, D, E, E, F, F, G, G, H, H...

• A, B, A, B, C, D, C, D, E, F, E, F, G, H, G, H,...

• A, B, C, D, E, F, G, H, A, B, C, D, E, F, G, H,...

For achieving time diversity with repetition coding which of the following operations is performed at the receiver

• Energy detector

• Phase detector

• Maximal Ratio Combining

• Rake receiver

Assuming that channel gains across slots are independent, how does probability of error scale when using repetition coding and sending symbol sequence as follows:

A, A, A, B, B, B, C, C, C, D, D, D, E, E, E, F, F, F, G, G, G, H, H, H...

• SNR^-1

• SNR^-2

• SNR^-3

• SNR^-4

Assuming that channel gains across slots are independent, how does probability of error scale when using repetition coding and sending symbol sequence as follows:

A, B, C, D, E, F, G, H, A, B, C, D, E, F, G, H,...

• SNR^-1

• SNR^-2

• SNR^-3

• SNR^-4

Which of the following is a deep-fade event when using repetition coding with MRC at receiver?

• ||h|| is "small"

• For any l, |h_l| is "small"