Question 1: Assuming 4 stations with chip sequences defined as: A = (-1 -1 -1 +1

Question

Question 1:
Assuming 4 stations with chip sequences defined as:
A = (-1 -1 -1 +1 +1 -1 +1 +1)
B = (-1 -1 +1 -1 +1 +1 +1 -1)
C = (-1 +1 -1 +1 +1 +1 -1 -1)
D = (+1 +1 +1 -1 -1 +1 -1 -1)
1) A CDMA receiver gets the following chip sequence: (1 +1 3 +1 1 3 +1 +1).
Which stations transmitted, and which bits did each one send? Show your calculations.
2) Suppose that A, B, and D are simultaneously transmitting 0 bits, using a CDMA system. What is the resulting chip sequence? Show your calculations. Question 1:
Assuming 4 stations with chip sequences defined as:
A = (-1 -1 -1 +1 +1 -1 +1 +1)
B = (-1 -1 +1 -1 +1 +1 +1 -1)
C = (-1 +1 -1 +1 +1 +1 -1 -1)
D = (+1 +1 +1 -1 -1 +1 -1 -1)
1) A CDMA receiver gets the following chip sequence: (1 +1 3 +1 1 3 +1 +1).
Which stations transmitted, and which bits did each one send? Show your calculations.
2) Suppose that A, B, and D are simultaneously transmitting 0 bits, using a CDMA system. What is the resulting chip sequence? Show your calculations. Question 1:
Assuming 4 stations with chip sequences defined as:
A = (-1 -1 -1 +1 +1 -1 +1 +1)
B = (-1 -1 +1 -1 +1 +1 +1 -1)
C = (-1 +1 -1 +1 +1 +1 -1 -1)
D = (+1 +1 +1 -1 -1 +1 -1 -1)
1) A CDMA receiver gets the following chip sequence: (1 +1 3 +1 1 3 +1 +1).
Which stations transmitted, and which bits did each one send? Show your calculations.
2) Suppose that A, B, and D are simultaneously transmitting 0 bits, using a CDMA system. What is the resulting chip sequence? Show your calculations.

Explanation / Answer

1. ANS

S · A = (+1 -1 +3 +1 -1 +3 +1 +1)/8 = 1

S · B = (+1 -1 -3 -1 -1 -3 +1 -1)/8 = -1

S · C = (+1 +1 +3 +1 -1 -3 -1 -1)/8 = 0

S · D = (+1 +1 +3 -1 +1 +3 +1 -1)/8 = 1

So station A transmits 1,

Station B transmits -1,

Station C transmits zero and

Station D Transmits 1.

2. ANS

A = (-1 -1 -1 +1 +1 -1 +1 +1)

A¯= (+1 +1 +1 -1 -1 +1 -1 -1)

B = (-1 -1 +1 -1 +1 +1 +1 -1)

B¯= (+1 +1 -1 +1 -1 -1 -1 +1)

D = (+1 +1 +1 -1 -1 +1 -1 -1)

D¯= (-1 -1 -1 +1 +1 -1 +1 +1)

A¯+B¯+D¯ = (+1 +1 -1 +1 -1 -1 -1 +1)

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.