Interference management strategy under cognitive dual-layer heterogeneous network system

Abstract

The invention discloses an interference management strategy under a cognitive dual-layer heterogeneous network system, particularly discloses a cell regionalization interference management strategy in a cognitive heterogeneous network, and relates to the technical field of wireless communication interference management. The interference management strategy is characterized in that a macro-cell user (MU) in a cell covered by a dual-layer heterogeneous network is taken as a main user, a femto-cell user (FU) is taken as a secondary user, the interference of the FU changes correspondingly on the basis of the change of the position where the MU is positioned, an area where the MU is positioned is judged through channel information, and interference alignment is performed on the interference of the FU and the interference of the MU respectively according to different characteristics of interference distribution in different areas, thereby lowering interference to the FU and the MU. The inference alignment is realized through pre-coding design of each transmitting end of the FU and the MU. A higher rate is provided for a next-generation wireless cellular network. Particularly, under the condition of rare frequency band resources, a solid physical foundation is laid for the utilization of idle frequency band resources, appropriate access to idle frequency bands and increase in the frequency utilization ratio.

Description

technical field [0001] The present invention relates to the technical field of wireless communication interference management, in particular to a cell-regional interference management strategy in a cognitive heterogeneous network. This interference management strategy ensures that femto Communication quality of cellular users (FU) and macrocellular users (MU). Background technique [0002] Femtocells are mainly designed for indoor wireless communications, providing higher rates for next-generation wireless cellular networks. The introduction of femtocells alleviates the load on macrocell base stations and the coverage problems that often exist. However, femtocell networks share the same frequency band resources with existing macrocellular networks, which will cause unavoidable co-channel interference. At the same time, frequency band resources are scarce resources. How to use idle frequency band resources has become a hot spot in wireless communication research in recent ye...

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Problems solved by technology

After searching the articles of the existing interference alignment technology, it was found that the literature Amir, M., EI-Keyi, A., Nafie, M.P: 'Constrained Interference Alignment and the Spatial Degrees of Freedom of MIMO Cognitive Networks' (IEEE Trans. Inf.Theory, 2011, 57, (5), pp.2994-3004), studied the coexistence of cognitive users and primary users in the channel, the cognitive user sender is limited by external constraints by designing precoding In order to reduce the interference to the transmitting end of the primary user, and study the spatial degree of freedom of the cognitive MIMO system, this paper only discusses the reduction of the interference received by the primary user and the degree of freedom achieved by the cognitive user, and does not discuss the primary user and Cognitive user transfer performance is discussed

[0004] Literature Maso M, Cardoso L S, Debbah M, et al. Cognitive interference alignment for OFDM two-tiered networks[C] / / Signal Processing Advances in Wireless Communications (SPAWC), (2012IEEE13th International Workshop on.IEEE,2012:244-248 In ), the interference alignment technology is used to optimize the precoding, which improves the spectrum utilization rate under the double-layer heterogeneous network. However, the interference caused by the secondary user communication to the primary user is simply regarded as background noise

[0005] Literature Guler B, Yener A. Selective Interference Alignment for MIMO Cognitive Femtocell Networks[J]. (Selected Areas in Communications, IEEE Journal on, 2014439-450) proposes a selective interference alignment for ensuring the communication quality of femtocell users Alignment, the main cross-layer interference is selected for interference alignment, and the minimum mean square suppression is performed on the same-layer interference. While reducing the bit error rate of femtocell users, it also speeds up the convergence of the interference alignment algorithm. Does not guarantee the communication quality of macro cell users

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