Multicarrier communication method and device having no time and frequency protection intervals

Abstract

The invention provides a multicarrier communication method and device having no time and frequency protection intervals, and belongs to the technical field of information transmission. Orthogonality, required by a multicarrier system, between sub carriers waves is abandoned; from the point of a sub carrier wave modulation signal extraction, through combinations with a sine and cosine frequency conversion technology and a basic characteristic of a Hilbert conversion, sub carrier wave modulation signals are extracted from received signals one by one, and separate demodulation is performed on the sub carrier wave modulation signals then, so the common problem that an orthogonal system multicarrier system has the high dependence degree of the orthogonality between the sub carrier waves, multicarrier transmission having no time and frequency protection intervals is achieved, and frequency spectrum efficiency and power efficiency of the multicarrier system are improved. In a multi-path attenuation channel, compared with an OFDM multicarrier technology, the method and device have an obvious performance advantage. The communication method device provided by the invention are suitable for any communication frequency band, and a set of new scheme is provided for design of a 5G mobile communication system, a new-generation broadband satellite broadcast television system and other communication systems.

Description

technical field [0001] The present invention relates to radio communication technology, more specifically, the present invention relates to a multi-carrier communication method and device without time and frequency guard interval, belonging to the field of information transmission technology. The invention can be applied to all wired and wireless communication systems using multi-carrier modulation and demodulation technology and common communication lines using single carrier modulation and demodulation technology. Background technique [0002] In recent decades, multi-carrier modulation technology has been greatly developed. This type of modulation technology has been widely used for its outstanding spectral efficiency and anti-interference ability. OFDM (Orthogonal Frequency Division Multiplexing) modulation technology is a typical multi-carrier modulation Technology has been widely used in wired, radio and optical communications, and has formed a variety of wired and wir...

AI Technical Summary

Problems solved by technology

Due to the existence of multipath interference and the unsatisfactory characteristics of the transmission channel, the modulated signal will inevitably be distorted during transmission, which will inevitably affect the orthogonality between subcarriers, and then affect the performance of the system.

In a typical OFDM multi-carrier modulation system, the influence of multipath interference on signal orthogonality is overcome by inserting a cyclic prefix (Cyclic Prefix, CP). The cyclic prefix does not transmit information, and its existence reduces the spectral efficiency and power efficiency

The length of the cyclic prefix is ​​usually 1 / 5-1 / 4 of the symbol period. Taking the cyclic prefix of 1 / 5 symbol period as an example, its system bandwidth utilization rate in the most ideal case is 1.6Baud / Hz / s, which is the same as 2Baud There is a gap of 0.4Baud in the theoretical limit of / Hz / s, and the loss of spectral efficiency is as high as 20%. At the same time, the cyclic prefix will also cause a loss of signal-to-noise ratio of about 1dB in the system.

Furthermore, the role of the cyclic prefix is ​​limited, and it cannot solve the problem of orthogonality destruction caused by more serious multipath interference and other distortions

In addition, OFDM multi-carrier transmission systems usually need to use virtual carrier technology for carrier synchronization and channel estimation, which will further increase the system spectrum efficiency and power efficiency overhead, and reduce the actual transmission efficiency of the multi-carrier system

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