Single-rate and multi-rate multi-service systems for next generation and beyond communications

Abstract

Abstract-To flexibly support diverse communication requirements (e.g., throughput, latency, massive connection, etc.) for the next generation wireless communications, one viable solution is to divide the system bandwidth into several service subbands, each for a different type of service. In such a multi-service (MS) system, each service has its optimal frame structure while the services are isolated by subband filtering. In this paper, a framework for multi-service (MS) system is established based on subband filtered multi-carrier (SFMC) modulation. We consider both single-rate (SR) and multi-rate (MR) signal processing as two different MS-SFMC implementations, each having different performance and computational complexity. By comparison, the SR system outperforms the MR system in terms of performance while the MR system has a significantly reduced computational complexity than the SR system. Numerical results show the effectiveness of our analysis and the proposed systems. These proposed SR and MR MS-SFMC systems provide guidelines for next generation wireless system frame structure optimization and algorithm design.

Multi-Service System: An Enabler of Flexible 5G Air Interface

“…4 (a and b), the orthogonality between the subcarriers in one service is ensured by taking the corresponding columns of the full-size inverse discrete Fourier transform (IDFT) modulation [14]. One of the important roles of subband filter is to reduce the ISvcBI among the services.…”

“… Due to the subband filtering, the filter gain at different subcarriers in one subband may be different, resulting in uneven power allocation among subcarriers and, hence, performance loss [3].  Multi-rate (MR) implementation may be essential to make the multi-service system complexity affordable [14]. However, compared with single-rate (SR) implementation, MR may degrade the system performance due to the intersubband-interference (ISubBI) generated in up/downsampling process.…”

“…Note that this article will focus on the fundamental limitations and applicable scenarios for the multi-service systems based on F-OFDM and UFMC waveforms. The original waveform signal model can be found in [4] [14]; while the mathematical model of a multiservice system and the details of algorithms used in the article can be found in [3] [14]. It must be noted that in a singleservice system (such as LTE) with single numerology, intercarrier-interference (ICI) defines the interference generated among the subcarriers.…”

Cyclic Prefix-Based Universal Filtered Multicarrier System and Performance Analysis

“…1, and unlike the original UFMC system (where CP is an option can be added after subband filtering) [1], we add the CP before subband filtering. In addition, the proposed CP-UFMC system has exactly the same receiver implementation as CP-OFDM system, which avoids zero padding (and down-sampling) as well as high-order DFT operation as implemented in the original UFMC system [1], [2], [4].…”

“…Universal filtered multi-carrier (UFMC) systems offer a flexibility of filtering subbands consisting of arbitrary number of consecutive subcarriers to suppress out of band (OoB) emission, while keeping the orthogonality between subbands and subcarriers in one subband [1], [2], [3], [4]. Comparing to other candidate waveforms for the next generation wireless communication systems, it employs low complexity one-tap channel equalization similar to the orthogonal frequency division multiplexing (OFDM) system but offers much lower OoB emission.…”