AN2254 Freescale Semiconductor / Motorola, AN2254 Datasheet - Page 18

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

Results
signal before complex scrambling, and Figure 7 shows the signal constellation after the complex scrambling
operations. The I-Q/code multiplexed signal with complex scrambling results in a rotated QPSK constellation.
Figure 7 shows the resulting constellation achieved by both the Matlab and the StarCore DSP implementations.
Table 2 shows the assembly code results for PN code generation and formation of the pn_generation complex
scrambling sequence function for one frame. The second row of the table shows the results for scrambling of an I-
Q/code multiplexed signal in the cmplx_scrambling function for one frame.
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Scrambling Code Generation for WCDMA on the StarCore™ SC140/SC1400 Cores, Rev. 1
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Figure 7. QPSK Constellation Map after Complex Scrambling
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Figure 6. QPSK Constellation Before Complex Scrambling
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X (Blue) − DSP output
O (Green) − Matlab output
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