Design and Implementation of Shared Memory for Turbo and LDPC Code Interleaver

Abstract

In 4G turbo and 5G LDPC, in order to realize a flexible, low-power, low-cost shared general-purpose block interleaving hardware module, it faces the challenges of interleaving structure integration, fewer gate circuits, parallel multistream operation, and switching between standards. Facing these challenges, after studying 3GPP TS 36.212 V15.4.0 and 3GPP TS 38.212 V15.4.0 protocols, common part of two major interleaving module standards is found. For the block interleave module in the rate matching of the 4G downlink turbo code and the bit interleave module after the rate matching of the 5G NR downlink LDPC code, this paper first designs a memory and implements the two codes interleaving on it. Then, based on the Altera Quartus prime platform and ModelSim for functional verification. Experimental results show that under SMIC 28 nm, operating frequency 50MHz, after synopsys synthesis, the memory module area is $0.17\mu {\text{m}}^2$ , and the power consumption is 6.45 mW. Through the shared design, 32 bits parallel access, and switching between standards, the proposed scheme reduces the hardware cost, power consumption, and clock overhead, and improves the flexibility of 4G LTE and 5G NR communication downlink hardware implementation.