Digital Modulation Schemes Evolution Systems - MyAssignmenthelp.com

Question: Discuss about the Digital Modulation Schemes Evolution Systems. Answer: Introduction The case is about the LTE cellular networks which is mainly for handling the mobile communication technology using the Orthogonal Frequency Division Multiplexing. It is mainly based on the increased capacity and the speed that makes use of the different interface of the radio with the network improvements. The specifications are related to the working and handling the 4G LTE which relates to the advancements of the WiMAX, evolvement of the high-speed packet access and the LTE to bring the change in the 3G technologies. The LTE Advanced is for the 3GP standards which includes the technological advancements with the higher flexibility of the radio interface that mainly aims to handle and bridge the gap between the 3rd and the 4th generation. The 3GPP works on the requirements which includes the systems that support the peak data rates for 100Mbps in the downlink. The downlink is averaged with the user throughput and the spectrum efficiency. The OFDM is for the utilization of the digita l multi-carrier modulation methods, where the data is transmitted on the different narrow band subcarriers. The LTE downlink make use of OFDM, where the uplink is mainly for the different types of the modulation schemes, which is known as the single-carrier frequency division multiplexity. The OFDM is for the high peak to average the power ratio that requires to work on the linear power amplifier with the overall forms of the lower efficiency. The poor quality is for the operations of the battery handsets with the SC FDMA that has a lower PAPR which is for the portable implementation. The LTE provides the spectral efficiency which is mainly for the higher data rates with the permits that are set for the different multiple users. [3] There are divisions which are for the specific channels and for carrying the spacing in the subcarriers that are orthogonal. It mainly comes with the subcarrier spacing and handling the LTE Channel spacing, where the high speed of the serial data need to be transmitted which is then divided into the slower streams as well with the modulation to one of the subca rriers. OFDM makes the use of the frequency and the time that is mainly for the handling of data spread. With this, there is a need to analyze the higher speeds with the signal reliability. It is based on the subcarriers and how the data is set with different symbols that are for the multiple bits like Q PSK 2 bits, 16QAM 4 bits, and 64QAM 6 bits. [4] The range with the higher-level modulation is set with the higher rate of data. The check is on handling the deals with the assignment of the multiple users with the shared forms of the communication resource. The OFDMA scheme is based on working with the DFT processing and handling the elements which are related to the lower PAPR with the benefits related to the reduced cost of the power amplifier. With this, the analysis is based on the performance gaps which are small and the SC-FDMA advantage is mainly of the lower PAPR that is for the uplink wireless transmission taking hold of the communication system. [5] The constellation symbols are for the sequence of bits which are transmitted like BPSK (Size=1), QPSK (L=M2), and M-Quadrature Amplitude Modulation. There are different transmitter users which are assigned for the different Fourier coefficients to mainly handle the mapping and the de-mapping of the blocks. The receiver side is for the de-mapping block with IDFT and detection for the user signals. The guard intervals with the cyclic repetition are introdu ced with the symbols which are mainly for the time spread factors mainly by the multi-path proportion. In SC-FDMA, the multiple access is mainly among the users which is made possible through the assignment of the different users that tends to take a set for the non-overlapping of the Fourier coefficients and the sub-carriers. [6] The SC-FDMA is mainly to take hold of the single carrier transmit signal with OFDMA that is for the transmission scheme. The subcarrier mapping could be localized and the distributed mapping. The localized mapping is set with the DFT outputs that are set of the consecutive subcarriers mainly to confine to the system fraction. Here, the case is related to the occupied forms of the subcarriers that are spaced over the entire bandwidth. The major advantages of OFDM are the efficient use of the spectrum which is set for the overlapping with divisions of the channel that is set into the narrowband flat fading sub channels. It is mainly resistant to the frequency which is for the selective fading than the single carrier systems. The elimination of the ISI and IFI is mainly using the cyclic prefix, where the use of the adequate channel coding and the interleaving is where one can easily recover the symbols that are lost due to the selectivity of the frequency. The channel equalization is simple with the use of adaptive equalization techniques and the single carrier systems. [7] The possibility is based on handling the reasonable forms of the complexity measures. The OFDM is also for the use of the maximum likelihood with the focus on the use of FFT techniques that are set with the modulation and the demodulation of the functions. It is seen that they are less sensitive to the sampling timing offsets and has been set for the different types of the system carriers. The protection is mainly against any type of co-channel interference with the parasitic noise that is set like the amplitude and the large dynamic range which requires to handle the RF power amplifiers with the higher peak to the average ratio of power. OFDM is the form of the signal modulation which can divide the higher rate of the data that has been set on the modulating stream and is then placed on the slow forms of the modulated narrowband spaced subcarriers. The modulation is mainly adopted with the Wi-Fi Arena where the standards like 802.11a, 802.11n, 802.11ac are equipped with the telecommunication. The broadcasting standards are set with the adoption to the Digital Radio Model which is for the long and the short-wave bands. The system includes the spaced modulated carriers where the modulation is in the form of the data and the voice. It is, then applied to the sidebands which is spread with all the important forms of the receiver to be able to handle the signal with the data demodulation. The signals are then transmitted to the other which are spaced and worked on through the easy processes. The requirements are based on working over the receiving and transmitting systems which are linear. For the non-linearity, there is an interference which is mainly set in between the carriers. This is the result for the inter-modulation distortion designing with introduction of some of the unwanted signals that leads to cause the interference with the impairing of the orthogonality of the transmission. The patterns are based on working over the multi-carrier systems with OFDM focusing on the RF final amplifier where the output of the transmitter can handle the peak with the lower average power. Along with this, the efficiency is also measured based on how the carriers of the signal are measured with easily handling the payload. [8] This reduce the data rate that is taken by each carrier. The major focus is on the interference with the distribution of data that is set with some advantages. The system is based on the handling of the peak data rates which are for 100 Mbps for the downlink and for 50 Mbps which is for the uplink. Here, the downlink and the uplink is for the user throughput per MHz where there are 5% point of the CDF. The requirements are based on the higher degree of commonality of functionality with flexibility to support and work on the different range of the services and the applications in the effective manner. This will help in improving the user-friendly applications, services and the equipment with the worldwide roaming capability and the enhancement in the peak data rates that are set for handling the advancement of the services and the applications. The LTE advanced requirements are based on meeting the increased peak data rates to reach the ITU requirements based on improvement of the cell edge data. The other requirements are based on working over the peak data rates which are related to the latency, system that can support the downlink peak sp ectral efficiency with the configurations based on defining the base of the coverage with inter-site distance of 500m and the pedestrian users. The advancement is set with the features of the downlink and the uplink implementation where the SC-FDMA is for the configuration with the equalization that is at the receiver side, with DFT calculations and handling the frequency selective fading and phase distortion. [9] The major advantage is based on working with the equalization process which is achieved through the receiver side after the calculation of DFT is done. With OFDM, the user requirements are based on the ability to handle the channel conditions and then work on the attenuation for the higher frequency with the long copper wire. The narrowband interference with the frequency selective fading is mainly set due to the multi-path. This is to take hold of the higher spectral efficiency which is then compared to the other kinds of the double sideband modulation schemes. They are important and efficiency based on the implementation using the FFT (Fast Fourier Transform). The accuracy with the frequency synchronization is mainly in between the receiver and the transmitter which includes the cross talk between the sub-carriers. The effects are based on the forms which include the worsening of the speed with the simplified type of the equalization process that is caused by the multipath propagation. [10] The OFDMA is for the multiuser version with the frequency that is defined for the multiple access and to handle the assigning of the subsets to the different individual users. They are mainly to allow the lower data rates that are set from the different users. The focus is on allowing the simultaneous low data rate transmission from the different users with the improvement of the robustness and the fading with the needs of the modification to the air interface. This will also enable the single frequency network coverage with resistance and gain to the frequency selective fading. Conclusion The performance of the systems of LTE is based on the Shannon limit which is based on managing the higher rates of the data. Along with this, there is a need to focus on the signal to noise ratios where the approaches are based on the improvement of the values. One can easily meet the higher peak data rate requirements with the compatibility set through the different LTE carrier components. [4] The implantation could also be helpful for the improvement of the data rates with the use of the different antenna system. The coordination is based on involving the transmission points and then setting the network node paths with the long distances where the other nodes are eliminated, thereby, allowing the higher data rate patterns. References Saleem M, Ali M, Ali A. Location Awareness Impact on Long Term Evolution (LTE) System. Evolution. 2016 Feb;135(3). Krishna P, Kumar TA, Rao KK. M-QAM BER and SER Analysis of Multipath Fading Channels in Long Term Evolutions (LTE). International Journal of Signal Processing, Image Processing and Pattern Recognition. 2016;9(1):361-8. Zhang G, Pan KJ, Tsai AY, inventors; Interdigital Technology Corporation, assignee. Method and apparatus for synchronization in an ofdma evolved utra wireless communication system. United States patent application US 15/094,720. 2016 Apr 8. 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