Signal demodulation method

Abstract

The invention discloses a signal demodulation method, specifically comprising the following steps of: obtaining an integral transmission code word; calculating estimated values of three non-differential phases according to majority logic; deciding the most unreliable one of the three non-differential phases, and judging the other two reliable phases; calculating decision values of the remaining two phases according to the two decided phases; and looking up a table according to the four obtained phases to get the input bits. The demodulation method provided by the invention can fully reduce noise influence on signals and effectively improve signal demodulation performance.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a signal demodulation method. Background technique [0002] The IEEE 802.11b protocol stipulates that a complementary code keying (CCK) modulation is used at a data rate of 11 Mbps. CCK is defined by a set of 256 codewords, each codeword has 8 complex code chips, and the codeword set has quasi-orthogonality. If the common phase of the codewords is not considered, the 256 codeword sets are actually composed of 64 codewords, and the set of the 64 codewords is called the basic codeword set of CCK. [0003] Complementary code keying modulation divides the input bit stream into groups of 8 bits, denoted as (d 0 , d 1 , d 2 , d 3 , d 4 , d 5 , d 6 , d 7 ), the first two bits in each group of 8 input bits (d 0 , d 1 ) is encoded according to Table 1 to obtain the phase The remaining 6 bits are coded in pairs according to Table 2, namely (d 2 , d 3 ), (d 4 , d 5 ) and (d...

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Problems solved by technology

[0026] The algorithm of large number logic decoding is very simple, requires few resources, and the processing speed is very fast, but the CCK demodulation performance of this decoding method is relatively poor

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