基于CP-free OFDM的上行SCMA收发机设计和性能分析

doi:10.11959/j.issn.1000-0801.2021132

摘要/Abstract

摘要：

典型稀疏码分多址（sparse code multiple access，SCMA）系统采用带循环前缀（cyclic prefix，CP）的OFDM实现抗多径衰落无线传输，其容量受限于CP开销。针对此问题，提出了一种基于时域预编码的稀疏码分多址（time domain precoding-OFDM SCMA，TDP-OFDM SCMA）上行接入方案。给出了发射机、接收机的主要结构并进行不同信道、不同过载率和不同信道估计误差下的系统容量以及误比特率性能仿真，最后对TDP-OFDM SCMA信号的功率效率展开了分析。仿真结果表明：在相同过载率下，TDP-OFDM SCMA系统容量较CP-OFDM SCMA最高可提升25%。

关键词: SCMA, MPA, 上行, CP-freeOFDM, 系统容量

Abstract:

A typical sparse code multiple access (SCMA) system utilizes orthogonal frequency division multiplexing (OFDM) technology with cyclic prefix (CP) to combat multipath fading in wireless channels.Therefore, its capacity is reduced by the CP-insertion.To address this issue, the SCMA scheme based on CP-free OFDM using the time domain precoding (TDP) algorithm was proposed and the proposed scheme was termed as TDP-OFDM SCMA.The transceiver structure was designed, and the capacity plus the bit error rate (BER) performances under various channels with different overload rates and with channel estimation errors were evaluated via the simulations.Also, the power consumption problem in TDP-OFDM SCMA was discussed.The simulation results show that under the same overload rate, the capacity of TDP-OFDM SCMA can be increased by up to 25% if compared with the SCMA based on CP-OFDM.

Key words: SCMA, MPA, uplink, CP-free OFDM, system capacity

中图分类号:

TN929.5

周立, 刘喜庆. 基于CP-free OFDM的上行SCMA收发机设计和性能分析[J]. 电信科学, 2021, 37(6): 23-32.

Li ZHOU, Xiqing LIU. Transceiver design and performance analysis for uplink SCMA based on CP-free OFDM[J]. Telecommunications Science, 2021, 37(6): 23-32.

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ETU		EVA		EPA
时延/ns	功率/dB	时延/ns	功率/dB	时延/ns	功率/dB
0	-1.0	0	0.0	0	0.0
50	-1.0	30	-1.5	30	-1.0
120	-1.0	150	-1.4	70	-2.0
200	0.0	310	-3.6	90	-3.0
230	0.0	370	-0.6	110	-8.0
500	0.0	710	-9.1	190	-17.2
1 600	-3.0	1 090	-7.0	410	-20.8
2 300	-5.0	1 730	-12.0	N/A	N/A
5 000	-7.0	2 510	-16.9	N/A	N/A