# Performance Analysis of NR-DCSK Based Copper Cable Model for G.fast Communication
## 1 Introduction
However, under certain extreme circumstances they could reach 30 to 80% through favorable coupling conditions. The study [7] compared Minimum Mean Square-Error (MMSE) precoding with linear Zero-Forcing (ZF) and TH-ZF precoding, which showed its feasibility for G.fast. It was shown that TH-ZF precoding performs better than linear ZF precoding and that MMSE precoding performs better than ZF precoding. Under 212 MHz G.fast conditions, spectrum optimization was found to improve the performance of all three methods for pure G.fast FTTdp. However, one of the algorithms was criticized for being extremely complex and TH precoding required more sophisticated hardware. Vectoring operations were found in [8] to be affected when the original channel matrix of a vectoring group was disrupted by an abrupt termination change caused by a disorderly leaving event (DLE). A reflective crosstalk coefficient model was introduced and residual crosstalk sources and paths were found using the FEXT-reflected-NEXT (FRN) model. Hence, a method was proposed for updating the downstream precoder and estimating the channel parameters. The old precoder was retained for a short time after a DLE, significantly reducing the perturbation time and reducing the estimation complexity from \(O(K^{2})\) to \(O(K)\). This was achieved by reducing the remaining crosstalk on the direct channel of the outgoing line. The aim of [9] was to analyze the impact of spectrally compatible bandplans and synchronization on coexistence problems between G.fast and vectored VDSL2. Using realistic FTTdp network distributions and developed FEXT and NEXT channel models, G.fast and vectored VDSL2 were operated together from the distribution point. It was found that Vectored VDSL2's performance was minimally affected by synchronization, while G.fast's performance actually improved. The feasibility of synchronous transmission methods was questioned, but spectrally compatible band plans were seen as promising as they offered G.fast low-cost vectorized VDSL2 with near-optimal performance. In [10], some strategies have been considered to improve the coverage and data rates of G.fast systems. The performance impact of increasing bit constellation size, power spectrum density (PSD) mask level, and maximum aggregate transmit power (MAXATP) was investigated. It was found that larger bit constellations and MAXATP, while beneficial for G.fast systems, also result in higher transfer rates, which negatively impacts coexisting systems. To mitigate this, a G.fast PSD mask modification was proposed along with a PSD shaping method of VDSL2 systems. The simulation results showed that this approach reduced the performance degradation of coexisting systems with a moderate loss in G.fast performance, although it was not optimized for G.fast. It was recommended that future studies investigate more complex spectrum shaping methods and the effects of modified PSD masks on electromagnetic leakage. G.fast has updated DSL technology with FTTH, enabling operators to provide multiple broadband services with low propagation delay and aggregate bit rates of up to 1 Gbit/s as in [11]. These services included interactive games, high quality audio and voice, and multi-channel High Definition (HD) video. In-house cabling and low-quality copper drop cables were used to operate G.fast. Panel power issues were resolved through regeneration, and customer self-installation improved system management, reduced costs, and improved customer convenience. THP has been investigated in [12] as a G.fast replacement. THP losses and their advantages over linear precoding, particularly modulo losses, have been the main topics of discussion. A method was presented that avoids bit error rate simulations and produces similar results-estimating the modulo loss based on the SNR. It was found that higher coding gain is accompanied by larger modulo loss. To support legacy devices, a mixed receiver approach has been proposed, allowing CPE-side modulo receivers to be activated on demand.