在GNU Radio中实现CC1110的PN9扰码器时结果不符，寻求技术帮助

Hey there! Let's work through getting your CC1110 data whitening working correctly in GNU Radio Companion. I can see where the parameter mismatch is happening, so let's break this down step by step.

First, let's recap the CC1110 whitening specs we need to match: #

• PN9 LFSR with polynomial (x^9 + x^5 + 1)
• Initial seed: 0x1FF (9 bits all 1s)
• Whitening is done by XOR-ing each input bit with the corresponding bit from the PN9 sequence

The main issue: Your Scrambler module mask is wrong #

You currently have the mask set to 0x11, which corresponds to a 4th-order polynomial ((x^4 + 1))—this doesn't match the 9th-order polynomial required for CC1110's PN9 sequence. Here's how to fix the parameters:

Correct Scrambler Module Configuration:

• Mask: Set this to 0x221 (decimal 545). This binary value is 1000100001, which maps directly to our polynomial: the leftmost bit represents (x^9), the 5th bit from the right represents (x^5), and the rightmost bit represents the constant term (1).
• Seed Value: Keep this at 0x1FF—this is correct for the CC1110's initial LFSR state (9 bits all high).
• Length: Keep this at 8—since you're processing 8-bit bytes, this tells the module to handle each input symbol as 8 bits.
• Scramble/Descramble: Ensure this is set to Scramble (you want to apply whitening, not reverse it).
• Bit Order: Double-check this setting! CC1110's whitening processes bits in the order they're transmitted (usually MSB-first for the example you shared). If your output still doesn't match, try toggling between "MSB First" and "LSB First"—this is a common gotcha for byte-wise processing.

Let's verify with your example data #

Your input byte 0x0A (binary 00001010) should XOR with the first PN9 byte 0xFF (binary 11111111) to produce 0xF5 (binary 11110101)—exactly what the application note shows. With the corrected mask, the Scrambler module should generate the correct PN9 sequence to make this happen.

Troubleshooting tip #

If you're still seeing odd output (like the repeated 0x01 bytes), double-check that your input file is being read correctly (make sure you're using a "File Source" module set to read bytes, not packed bits) and that the Scrambler is connected properly in your flowgraph.

内容的提问来源于stack exchange，提问作者aloomis