A Cognitive Interference Management Strategy in Two-layer Heterogeneous Network System

Abstract

The invention discloses an interference management strategy under a cognitive two-layer heterogeneous network system, specifically refers to a cell regionalized interference management strategy in a cognitive heterogeneous network, and relates to the technical field of wireless communication interference management. It includes: in a cell covered by a two-layer heterogeneous network, the macro cell user (MU) is the main user, and the femto cell user (FU) is the secondary user. Based on the change of the location of the MU, the interference of the FU will be corresponding The area where the MU is located is judged by the channel information, and then according to the different characteristics of the interference distribution in different areas, the interference of the FU and the interference of the MU are respectively aligned to reduce the interference of the FU and the MU. The interference alignment is implemented through the precoding design of each transmitting end of the FU and MU. To provide a higher rate for the next generation of wireless cellular networks, especially in the case of scarce frequency band resources, how to use idle frequency band resources and opportunistically access idle frequency bands to improve spectrum utilization provides a solid technical and material foundation.

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 CognitiveNetworks' (IEEE Trans.Inf. In Theory, 2011, 57, (5), pp.2994-3004), when the cognitive user and the primary user coexist in the channel, the cognitive user sender is limited by external constraints by designing precoding to reduce The interference to the transmitting end of the primary user and the spatial degree of freedom of the cognitive MIMO system are studied. 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's transmission 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) Using interference alignment technology to optimize precoding and improve spectrum utilization under a two-layer heterogeneous network, but without considering the distribution of secondary user interference in the cell, the interference caused by secondary user communication to primary users is simply regarded as background noise

[0005] Literature Guler B, Yener A. Selective Interference Alignment for MIMOCognitive Femtocell Networks[J]. (Selected Areas in Communications, IEEEJournal on, 2014439-450) proposes a selective interference alignment to ensure the communication quality of femtocell users. 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 speeds up the convergence of the interference alignment algorithm, but the paper does not have Guarantee the communication quality of macro cell users

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