Further Investigation on Pilot Design for MIMO OFDM Systems in Multi-Cell Environment

Optimal pilot design in massive MIMO systems based on channel estimation

“…In the conventional MIMO‐orthogonal frequency division multiplexing (OFDM) systems, optimal pilot sequences design and channel acquisition were extensively investigated in the literature [29–31]. For massive MIMO systems, the optimal pilot sequences design to alleviate the pilot contamination and improve system performance were presented in [32–37].…”

Time Domain Correlation Based Joint Channel Estimation for Multi-Cell Cooperative OFDM Networks

“…In conventional non-cooperative cellular systems, general method for channel estimation is to mitigate or eliminate ICI with estimation of interference characteristic of adjacent cells firstly and then to estimate channel information, the results are not satisfactory and have a high computational complexity. In cooperative cellular systems, joint channel estimation (JCE), which is initially applied in a multi-user scheme, could be extended to a multi-cell environment and obtained better system performance as depicted in publications [3]- [6] when pilot sets of multiple cells are known. Assuming that the power delay profiles (PDP) of all channels (in this paper, we exploit the concept of PDP to precisely represent multipath delays power and multipath tap location [7] and the below is same) do not overlap and the pilot sequences of all cells remain the same, Ref.…”

“…[5] explained the relationship between time and frequency domain JCE in these systems. In [6], for enhancing the practical value of multi-cell JCE, the author further investigated on pilot design and presents two general optimal pilot sequences based on minimizing the MSE. However, the mentioned above multi-cell JCE algorithms need PDP knowledge of all multiple cells remained the same and known by receiver or pilot sequence sets of all cells being identical and other limitations.…”