Multi-user OFDM modulation method based on imbedded training sequence and LDPC code

Abstract

The invention discloses a multiuser OFDM modulation method based on embedded training sequence and LDPC coding, which includes the following steps: 1) each user inserting zero even in its own training sequence to form discrete FFT training sequence block; 2) each user performing LDPC coding to its own input data bit stream to further form an FFT coding data block; 3) directly superimposing the discrete FFT training sequence block and the FFT coding data block to form an FFT embedded training sequence coding data block; 4) adopting IFFT to switch the FFT embedded training sequence coding data block into a time-domain discrete sample block; 5) taking circulating prefix as guard interval to insert into the time-domain discrete sample block to from a signal frame; 6) using a Raised Cosine Roll-off Filter to perform pulse shaping to the signal frame; 7) upconverting the baseband signal to carrier. The method has advantages of short synchronization time, channel dwindle resistance and multiuser disturbance resistance and the like.

Description

technical field [0001] The invention belongs to the field of wireless communication, and more specifically relates to a multi-user OFDM (low density parity check code, Low Density Parity Check, LDPC; Orthogonal Frequency Division Multiplexing) based on embedded training sequences and LDPC codes , OFDM) modulation method. Background technique [0002] Wireless communication is one of the most important infrastructures in the modern information society. It has become a basic requirement for national progress and social development, and plays an important role in sustainable economic development and modern military defense construction. However, in the field of wireless communication, on the one hand, spectrum resources are limited; on the other hand, with the increase in the number of users and the expansion of business scope (especially the emergence of various high-speed data services) With the growth of broadband wireless communication, it plays an increasingly important r...

AI Technical Summary

Problems solved by technology

When LDPC coding was first discovered, it was not widely used in most cases due to the computational complexity of algorithms and encoders being too large for practical application.

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