# Performance Analysis of NR-DCSK Based Copper Cable Model for G.fast Communication
## 1 Introduction  
In response to growing customer demand for reliable, high-speed Internet, broadband networks using twisted pair copper, coaxial cable, and Fiber optics have been developed since the early 1990s. Digital Subscriber Line (DSL) technology is becoming increasingly popular due to its low cost and ability to provide high data rates using current copper infrastructure. With the advancement of DSL, expensive replacement of copper cables is no longer required for transmissions at very high bit rates. An experimental broadband system has been presented in [1] that uses telephone copper cables to support multimedia applications such as video-on-demand. The system uses discrete multi-tone modulation (DMT), which enables data rates between 10 and 55 Mbit/s depending on channel conditions. It describes the straightforward implementation of DMT and emphasizes the crucial role of synchronization for high data rates. It describes a newly introduced synchronization method that is critical to achieving optimal performance. To overcome new challenges [2], crosstalk cancellation, noise environments, and cable modeling were found to provide research opportunities. It was shown that improvements in digital modulation could reduce analog constraints, with the analog domain identified as a major bottleneck. It presented an overview for the necessity of reverse power supply in FTTdp and FTTB scenarios and presented the research methodology for selecting the best coding schemes. The characteristic impedance and propagation constant of twisted pair cables were described using a five-parameter causal model in [3]. The KHM model, whichfitted model parameters to measured data using a closed-form expression, was validated for frequencies as high as several hundred MHz. Applications in the frequency and time domains demonstrated the applicability of the model. According to experimental results, the model provides good accuracy for G.fast and can accurately model single segments as well as complex topologies with multiple segments and bridged branches. The XG-FAST system concepts were presented in [4] utilizing technology that could deliver 10 Gbit/s over short copper pairs. Using a hardware proof-of-concept platform, multi-gigabit speeds were demonstrated over typical drop lengths of up to 70 m. It has been demonstrated that 10 Gbps service up to 30 m is possible with an additional pair using bonding and phantom mode. It was predicted that fiber-to-the-door deployment would become possible with XG-FAST technology and it could overcome a number of traditional barriers to FITH deployment. The roll-out of FITH was expected to accelerate globally using XG-FAST single-subscriber devices; However, the physical layer and fiber network interface required standardization. In [5], two new ideas were presented that led to the highest minimum aggregate rate in the G.fast downstream: a novel Dynamic Ordering (DO) strategy and an ordered Tomlinson-Harashima Precoding (THP) scheme. In contrast to the current Equal Rate (ER) THP scheme, the proposed scheme showed superior adaptation to G.fast's asymmetric channel statistics. The scheme has been shown to be universally applicable in multi-input multi-output systems, with sum rates of THP consistently higher than ER-THP, although the results are specific to G.fast. Depending on the length of the loop and the use of vectoring, it was found in [6] that there was a proportional effect of Power Line Communication (PLC) interference on DSL technologies. Loops longer than 200 meters were not significantly affected by SPS interference. Vectored VDSL2 (VVDSL2) technology showed a 95% chance of data rate loss of less than 20% at a distance of 100 meters. This probability decreased to 75% and 60% at 300 and 700 meters, respectively. For non-vectorized VDSL2, the effect of crosstalk masking was less pronounced. For example, losses at fast data rates, although comparable to VVDSL2, were typically between 2 and 14%.