Synchronization sequence construction method in super cellular mobile communication device-to-device technology

Abstract

The invention discloses a synchronization sequence construction method in the super cellular mobile communication device-to-device technology, wherein the frequency domain synchronization sequences corresponding to each relay terminal node are all composed of periodic subcarrier groups, each subcarrier group comprises one non-zero subcarrier, and other subcarriers are all zero subcarriers. In the synchronization sequence constructed according to the method provided by the invention, a cyclic prefix is in the front of the sequence and a cyclic postfix is in the back of the sequence, influence of multi-path delay and timing difference of different trunk links on the performance of the synchronization algorithm is avoided, a cross-correlation operation and the corresponding weighted averaging can be performed for a receiving sequence and a transmitting sequence so as to get the timing estimation, and the frequency offset estimation is obtained by a subspace decomposition method. The method provided by the invention effectively solves the problem of multiple time bias and multiple frequency offset specially existing in a cooperative device-to-device scene in the cellular / super cellular mobile communication system, and is low in computation complexity, excellent in estimation performance and capable of effectively avoiding occurrence of abnormal value of frequency offset estimation.

Description

technical field [0001] The invention belongs to the technical field of synchronization in mobile communication, and relates to a method for constructing a synchronization sequence applicable to a cooperative transmission scenario in a cellular / super-cellular mobile communication system (D2D, Device-to-Device). Background technique [0002] The further improvement of network capacity in existing cellular mobile communication systems is subject to dual constraints of spectrum resources and energy consumption. Therefore, how to greatly increase network capacity with limited spectrum and energy is a huge challenge. Moderately separate the tightly coupled control coverage and service coverage in the existing cellular network, and then introduce flexible coverage of the network, elastic matching of resources, and a moderate service mechanism for services, so as to achieve energy efficiency and resources. Joint optimization, this is the core idea of ​​the newly proposed super cellu...

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Problems solved by technology

[0004] In the prior art, there is no synchronization sequence construction method specifically for the super-cellular communication system and the cooperative terminal direct technology; and for the same type of synchronization sequence constructed in the prior art, the subcarrier groups assigned to different cooperative relays are all composed of non-zero subcarriers. There is no zero subcarrier; frequency offset estimation based on the above-mentioned synchronization sequence will cause frequency offset estimation abnormal values ​​when the frequency offset parameters of each relay link take certain values, that is, estimation errors occur, and the abnormal value The occurrence is not a small probability; the existing multi-frequency offset parameter estimation method needs to do 2M dimensional search operations, even if the estimation algorithm can be simplified, it still needs 2M one-dimensional search operations, and the computational complexity is very large

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