Matched processors for two orthogonal signals for multiple access.

Question

The following worksheet specifies a pair of 10-sample CDMA orthogonal data signals: sA sub "1" in B5:B14 and sB sub "1" in C5:C14. Random transmitted bits DA sub "t" and DB sub "t" are computed in B1 and D1. The transmitted signal sAT sub "i" (in D5:D14) = sA "sub "i" if DAt=1 and =-sA sub "i" if DAt=0. The transmitted signal sBTi (in E5:E14) = sBi if DBt=1 and =-sBi if DBt=0. The Gaussian noise sequence Ni SD ? sub "N" is specified in F1. The detected signal X sub "i" is computed in G5:G14. The matched processor component sAiX sub "i" is computed in H5:H14 and VA is computed in H16. The detected bit DAr is computed in B2 from VA. The matched processor component sB sub "i" X sub "i" is computed in I5:I14 and VB is computed in I16. The detected bit DB sub "r" is computed in D2 from VB.





a. What is the formula in B1?

b. What is the formula in D1?

c. What is the formula in D2?

d. What is the formula in F2?

e. What is the formula in D10?

f. What is the formula in E10?

g. What is the formula in F10?

h. What is the formula in G10?

i. What is the formula in H10?

j. What is the formula in H16?

k. What is the formula in B2?

l. What is the formula in I10?

m. What is the formula in I16?

n. What is the formula in D2?

o. What is the formula in L1?

p. What is the formula in L4?

q. Compose ResetMA.

r. Compose XmitMA.

s. Compose AutoMA.

Answer 1

Sub ResetMA()

Range("L3").Value = 0

Range("L4").Value = 0

End Sub



Sub XmitMA()

Dim DAT As Integer

Dim DAR As Integer

Dim DBT As Integer

Dim DBR As Integer



Range("L3").Value = Range("L3").Value + 2 ' 2 bits xmitted

DAT = Range("B1").Value ' store w/o new transmit

DAR = Range("B2").Value DBT = Range("D1").Value

DBR = Range("D2").Value

If DAR <> DAT Then ' error

Range("L4").Value = Range("L4").Value + 1

End If

If DBR <> DBT Then ' error

Range("L4").Value = Range("L4").Value + 1

End If



End Sub

Sub AutoMA()

Dim Row As Integer

Row = 8

Range("K8:L15").Clear

Range("F1").Value = 0

Do While Row < 17

ResetMA

Do While Range("L3").Value < Range("L2").Value

XmitMA

Loop

Range("K" & Row).Value = Range("F1").Value

Range("L" & Row).Value = Range("L5").Value

Range("F1").Value = Range("F1").Value + Range("L1").Value

Row = Row + 1

Loop

End Sub