Bipolar binary shift pulse keying modulation and demodulation method

Abstract

The present invention discloses a bipolar binary shift pulse keying modulation and demodulation method. The method is characterized by carrying out the pulse modulation on a symbol 0 having the reverse polarity with the pulse modulation of a symbol 1 on the basis of a binary shift pulse keying modulation mode in a uniform orthogonal binary shift keying modulation and demodulation method and in the initial information modulation interval of each symbol cycle, thereby greatly reducing and even completely eliminating the all discrete line spectrums containing a carrier frequency, and substantially expanding the constellation point distances among the symbols. By adopting a dual matching filtering method of impact filtering-multiplying coherent carrier-low pass filtering or band-pass filtering- related demodulation to demodulate, and by utilizing the dual filtering noise reduction removing interference capability of the impact filtering and the low pass filtering or band-pass filtering and the dual symbol energy maximization effect of the coherent demodulation and related demodulation, a received signal to noise ratio and an energy utilization rate can be improved remarkably, and the noise restraint anti-interference performance of a system can be enhanced substantially.

Description

technical field [0001] The invention belongs to the technical field of high-efficiency digital information transmission, and relates to information modulation and demodulation in digital communication, in particular to a bipolar binary offset pulse keying modulation and demodulation method. Background technique [0002] The high-speed growth of multimedia data services puts forward higher and higher requirements for wireless communication, especially with the development of 3G and 4G broadband mobile communication networks, the continuous spectrum of lower frequency bands is almost exhausted. Like energy and water resources, spectrum is also an important strategic resource of the country. On the other hand, in order to improve the spectrum utilization rate, the bandwidth and the transmission power of the ultra-wideband wireless system are increased, and the noise background of almost the entire radio spectrum range is gradually raised from quantitative to qualitative changes...

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Problems solved by technology

[0017] However, there are still obvious deficiencies in unipolar ABSK pulse modulation, which are mainly manifested in: first, as figure 2 As shown in (a), there are a lot of high discrete line spectra in its spectrum, although it does not carry modulation information and affect the demodulation performance, it is obviously not conducive to the improvement of spectrum efficiency, and if no protection measures are taken, the Cause serious energy leakage to interfere with adjacent channel signals; in addition, whether it is figure 2 Spectrum analysis in (a) shows that its higher carrier component occupies part of the transmit power, or considering the unipolar characteristics shown in (3), its demodulation must depend on the amplitude of the actual receiver input signal A certain preset threshold makes unipolar ABSK pulse modulation sensitive to changes in channel characteristics, and the performance is not excellent enough

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