AN2254 Freescale Semiconductor / Motorola, AN2254 Datasheet - Page 17

• Manufacturer Part Number: AN2254
• Description: Scrambling Code Generation for WCDMA
• Manufacturer: Freescale Semiconductor / Motorola

In Figure 4 and Figure 5, the x-axis represents the number of the chip, and the y-axis represents the magnitude of
each of the chips. The StarCore DSP output is scaled up by a factor of 2 to account for the scaling factors used by
the DSP in an implementation of complex scrambling code. The complex scrambled signal obtained from the DSP
implementation matches the Matlab result. Figure 6 shows the signal constellation for the I-Q/code multiplexed
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−0.5
−1.5
−0.5
−1.5
1.5
0.5
−1
−2
1.5
0.5
1.915
−1
−2
1.915
2
1
0
2
1
0
Scrambling Code Generation for WCDMA on the StarCore™ SC140/SC1400 Cores, Rev. 1
Figure 5. Imaginary Part of Complex Scrambled Signal (Chips 19150–19250)
Figure 4. Real Part of the Complex Scrambled Signal (Chips 19150–19250)
1.916
1.916
1.917
1.917
1.918
1.918
Imaginary part of Scrambled Signal
Real part of Scrambled Signal
1.919
1.919
chip segment number
chip segment number
1.92
1.92
1.921
1.921
Green − DSP output
Blue −− Matlab output
Green − DSP output
Blue −− Matlab output
1.922
1.922
1.923
1.923
1.924
1.924
x 10
x 10
1.925
1.925
4
4
Results
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