Codebook based interference alignment in uplink coordinated multipoint systems

Abstract

Interference alignment (IA) in uplink coordinated multipoint (CoMP) has been proved to be able to improve the performance in next generation mobile cellular systems. In this paper, an efficient codebook-based Max-SINR IA aided uplink (UL) CoMP scheme with full cooperation at the receiver is proposed. Compared to conventional IA, codebook-based IA requires less feedback information and maintains the same significant improvement in system capacity. To avoid the exhaustive precoder search in codebook-based IA, the K-Best selection algorithm is adopted to efficiently perform precoder selection. Simulation results demonstrate that the proposed codebook-based IA and K-Best precoder selection algorithm can achieve a significant performance gain especially in severe interference environments.

A Low Complexity Configuration Selection Algorithm in IA-Aided Uplink Coordinated Multipoint Systems

“…5 to evaluate the performance in a more severe interference-limited environment. The transceiver design algorithm used here is the maximum SINR algorithm [10]. A typical scenario in 3GPP recommendation [5] is used with different number of antennas.…”

“…where In IA aided UL CoMP systems, the CU attempts to design decoder and precoder for each user with the goal to fulfill the constraints in (6). By adopting the iterative IA algorithms [10][11], the decoder and precoders for each user can be found. The corresponding achievable sum rate after the MMSE equalizing matrix in IA-aided UL CoMP systems is defined as…”

“…By aligning interference, the IA exploits the degree of freedoms (DoFs) for transmission of the desired signal, and improves the system sum rate in interference channel [6][7][8]. In addition to the interference channel, concepts of IA can also be used in CoMP systems to design practical IA-aided transceivers composed of precoders and a joint decoder in a CoMP system, and provide better performance than the conventional CoMP systems defined in LTE-A [9][10]. In those IA-aided transceiver design algorithms used in CoMP system, the design of precoders and decoders is based on the channel and the number of data streams transmitted by each user.…”

Interference alignment with efficient dynamic information selection for LTE-A uplink coordinated multipoint systems

“…The key idea is that users coordinate their transmissions, using linear precoding, such that the interference signal lies in a reduced dimensional subspace at each receiver. So far, there is no closed-form solution of IA for more than three users, so the iterative approached based on reciprocity have been employed to search the best IA algorithm [7][8][9][10][11][12]. In [8][9][10][11], authors use the iterative IA, i.e., the maximum signal to interference-plusnoise (Max-SINR) IA, to generate the nearly optimal solution.…”

“…So far, there is no closed-form solution of IA for more than three users, so the iterative approached based on reciprocity have been employed to search the best IA algorithm [7][8][9][10][11][12]. In [8][9][10][11], authors use the iterative IA, i.e., the maximum signal to interference-plusnoise (Max-SINR) IA, to generate the nearly optimal solution. However, the sum-rate performance can be further enhanced by selected information from other base stations properly by the CU in the uplink (UL) CoMP system of boundary communication.…”