Structured Pilot Sequence Design And Their Low Complexity Detection Algorithm

Massive machine type communication is one of the three major application scenarios of5 G.In this scenario,in order to realize rapid active user detection,we need to construct a pilot sequence set to support massive users,and design active user detection algorithm with low complexity.In this paper,the following two kinds of structured pilot sequences and their corresponding fast detection algorithms are analyzed:1.The pilot sequence set with Toeplitz cycle structure is generated based on the deterministic sequence set,and the active user detection algorithm with low complexity is implemented by using the Toeplitz cyclic structure of the pilot sequence and fast Fourier transform.2.A pilot sequence set with equal ratio property is constructed.Then,based on the covariance matrix of the received information,a fast active user detection algorithm with low complexity is implemented.The research shows that compared with the traditional random pilot sequence,the pilot sequence proposed in this paper has the advantages of simple implementation and small storage space.Furthermore,based on its corresponding fast detection algorithm with low complexity,the active user detection process is accelerated.The numerical simulation results show that the structured pilot sequence set constructed in this paper has better performance than the Gaussian random sequence set of the same size.