Convergence Of 4G To 5G With Respect To Modulation Techniques

Abstract— the massive advancement in wireless communication has made the demand of latest technology drastically increasing day by day. It is the most active part of our lives to overcome the constraints of 4-G technology, a modified version 5G (fifth generation) technology is introduced. The goal of writing this paper is to compare these two technologies with respect to their coding techniques. What advantages and disadvantages they have? Which one is better? Also the comparison of simulated results of their coding techniques. OFDM (Orthogonal Frequency Division Multiplexing) is the coding technique of fourth generation while UFMC (Universal Filtered Multi-Carrier) is for fifth generation.

Keywords— OFDM, UFMC, Coding technique, 4G, 5G, Flat IP, Modulation technique, Wireless communication.

Introduction

The wireless technology has seen phenomenal revolution from 1G to 4G since the last four decades and now all set to explore the 5G which is yet to be released around 2020. Presently the world is revolving around 4G. The motive behind migrating from one generation to next has been to achieve low latency, high data rate and efficient use of bandwidth in communication system. It is supposed that by 2020 there will be billions of devices and 4G will not be much sufficient to provide them connectivity, high data rates and path to exchange information, this is why 5G is needed to be release.

After the successful deployment of 3G and 4G, the real time communication (Video calls etc. ) was allowed to users and now 5G is designed in a way to give more real time communication by making it 10 times faster than 4G and reducing the latency up to 1 millisecond, giving support to IoT devices, Ubiquitous computing and Wearable devices with Artificial Intelligence capabilities. 5G network uses Flat IP Concept unlike the previous generation which use normal IP Addresses and this makes 5G unique. The key feature in 4G is its data rate which is up to 1 Gbps. 4G uses frequency below 6 GHz while 5G is looking towards using extremely high frequency of range 3 to 300 GHZ. With high frequency there is greater ability to support high data rate without interfering other signals, as greater the frequency greater the data rate and shorter the wave length which results in short antenna length. 5G is introducing the software defined Cellular network, it is supposed that SDN will help the operators to simplify the network management and support the exponential traffic growth by programmable base station and packet gateways.

Architecture

5G architecture consist of user terminal and a number of autonomous radio access technologies. Fig 1 shows the network architecture of 5G. 5G architecture has reduced the number of elements which results in low cost and low latency. 5G supports different Radio Access Networks like CDMA, LTE, GSM, GPRS, EDGE, Wi-Fi, WiMAX, LTE-Advanced, etc. Aggregator controls all the traffic of Radio Access Networks and provide them route to the gateway. IP Network use the flat IP concepts for all devices and Nanocore provides nanotechnology, cloud computing through which users can access their data, application remotely. The global content service provides global search engines, private as well as public portals.

Key Technology Mechanism

Multiplexing and modulation is the key mechanism in wireless communication. It allows user to share a single media with low and sometime no interference and perform transmission of data in available frequency channel. Efficient usage of spectrum is dependent on the modulation scheme and multiplexing techniques. In the previous generations FDMA, TDMA, CDMA, OFDMA has been used. Single carrier modulation technique was used in 2G and 3G. Single carrier uses equalizers to achieve high spectrum efficiency while in 4G high data rates was achieved using multi carrier modulation technique. Multi-carrier modulation converts a wideband carrier into multiple orthogonal narrowband carrier. The main attraction of multi-carrier modulation is its good mitigation property because through this modulation technique high bit streams can broke down into many lower bit stream rates.

In 4G OFDM used as modulation and multiplexing strategy. The major drawback in OFDM was its high peak-to-average power ratio and synchronization error. One single synchronization error in orthogonality of two signals can destroy the whole signal and results in ISI. 5G is using UFMC technique to get around the drawbacks of OFDM. UFMC is the abstraction of OFDM and FBMC modulation scheme. In OFDM the overall band is filtered out and in FBMC individually single subcarrier of band is filtered out and delivers the high spectrum efficiency. So, in UFMC the group of sub carrier is filtered out which results in high spectral efficiency with reduced filtered length.

Simulation

In figure 2, 3 and 4 the simulation of UFMC and OFDM has shown on the basis of different parameters. The parameters includes Fast Fourier transform, number of sub bands, sub band size, sub band offset, side lobe attenuation, bits per carrier, filter length. The simulation result shows that the less side lobes are achieved in UFMC which allows the higher spectrum usage and decrease the interference of other subcarriers.

Key Features Of 5G

• Global Access.
• High Uploading and Downloading Speed.
• HD TV.
• Cognitive Radio.
• Artificial Intelligence capabilities.
• Low Interference.
• Cloud Computing.
• Machine to Machine Communication.
• Low Latency and Greater capacity.

5G Comparasion With Previous Generations

Starting from 1g and now stepping towards 5G the wireless technology gone through massive changes. 1G was introduced in 1982 which used analog signal and FDMA scheme and a core network of PSTN and circuit switching with the limited capacity of 30 KHz and poor security and quality. By late 1980s 2G was emerged as a new generation in Wireless communication with digital signal and TDMA scheme. This generation mainly focused on SMS service with the bandwidth usage of range 30 to 200 KHz. Next to 2G, 2. 5G came which boosted up the data speed up to 144 kbps. In 2000, 3G was launched. This technology offers high data rate and boosted up the data speed up to 14 Mbps with packet switching and Internet as a Core network. It uses CDMA scheme. 3G was called CDMA200 in America and Universal Mobile Telecommunication System in Europe. 3G increased the bandwidth, introduced new services likes Global roaming, Video Conferencing, 3D gaming, Faster communication. Later on in 2010 4G introduced with the speed of 100 Mbps and IP based core network. It provides same features like 3G and have some additional services. It is combination of WiMAX and Wi-Fi. It provides high security, services at any time anywhere, faster internet with low latency. 5G is to be released and has extra ordinary data capabilities as compared to all previous generation. 5G will focus on world-wireless World Wide Web. It will offer data rate higher than 1 Gbps with Internet based core network and UFMC scheme. It will be faster than 4G with very low latency of 1ms.

Conclusion

The 4th generation technology which uses OFDM scheme has some drawbacks related to lower spectral efficiency. In this paper, we have discussed above the comparison of UFMC and OFDM. UFMC is considered to be more advantageous as compared to OFDM. It uses higher spectral efficiency than OFDM. Other benefits like filtering between the sub-bands which reduce the guard band and also their filter length. In UFMC the cyclic prefix is not used whereas in OFDM cyclic prefix is used in which 5-10% of the bits repeated itself. The above modulation scheme shows the characteristics of both transmitting and receiving communication ends of UFMC. It explores the numbers of different parameters values of sub-bands, different carriers, filter length, GWN, and SNR.