New improvement scheme about gaussian minimum shift keying (GMSK) modulation technology

Abstract

The invention relates to a digital modulation mode suitable for the wireless communication field. In the invention, firstly, a current existing gaussian minimum shift keying (GMSK) modulation technology is provided specifically. An insufficiency of the current existing GMSK modulation technology on a spectrum efficiency is analyzed. And then the new digital modulation mode based on the current existing GMSK modulation technology is provided. By using the modulation mode, contradiction between an error code function and the spectral efficiency can be fully considered to be solved. Binary information is converted into ternary data through precoding so that a transmission signal phase only has three kinds of hopping values. From aspects of emission and receiving, performance indexes of the frequency spectrum and the error code performance are measured. Using a matlab simulation platform can show that a frequency spectrum utilization rate and anti-interference performance of the modulation mode are higher and better than that of the GMSK modulation mode.

Description

technical field [0001] The invention belongs to the field of digital communication, in particular to a new scheme of GMSK modulation and demodulation technology. Background technique [0002] GMSK modulation technology is a high bandwidth efficiency constant envelope modulation scheme proposed in 1979. With its further development, it has been widely used in military radio, GSM system, GPRS system, digital TV, satellite communication and other fields. [0003] In fact, GMSK modulation is a partial response CPM modulation with a modulation factor of h=0.5, which is a binary modulation method evolved from MSK modulation. The MSK signal can be regarded as a continuous phase FSK signal with a modulation index of 0.5. Although MSK has the advantages of constant envelope, continuous phase, relatively narrow bandwidth and coherent demodulation, it cannot meet the strict requirements of some communication systems for out-of-band radiation. In order to compress the power spectrum o...

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Problems solved by technology

The simulation shows that with BT b , the more serious the inter-symbol interference, the bit error performance will gradually deteriorate, but on the other hand, the spectral bandwidth utilization of the signal at the transmitting end is increasing, so how to improve the GMSK modulation and demodulation scheme to make the spectral efficiency and bit error Reaching optimum performance at the same time is a problem to be considered in the present invention

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