The document discusses uplink power control for 5G networks. It analyzes the performance of turbo codes, subcarrier mapping schemes, and DFT precoded/non-precoded systems over linear and non-linear channels. Simulations were conducted to analyze inter-carrier interference, multi-access interference, and the near-far effect in multi-user systems with different clipping levels. Results showed that DFT precoded systems and BIFDMA mapping performed better than alternatives in non-linear environments. Performance decreased with more users due to increased multi-access interference.
LTE is required to support communication with terminals moving at speeds of up to 350 km/h, or even up to 500 km/h depending on the frequency band. The primary scenario for operation at such high speeds is usage on high-speed trains – a scenario which is increasing in importance across the world as the number of high-speed rail lines increases and train operators aim to offer an attractive working environment to their passengers. These requirements mean that handover between cells has to be possible without interruption – in other words, with imperceptible delay and packet loss for voice calls, and with reliable transmission for data services.
This documents will cover basic LTE principles along with some brief impression about LTE features. Additionally, LTE Link Budget, LTE Coverage & Capacity Planning and Cell Radius calculation methodology have been depicted comprehensively in this document.
LTE is required to support communication with terminals moving at speeds of up to 350 km/h, or even up to 500 km/h depending on the frequency band. The primary scenario for operation at such high speeds is usage on high-speed trains – a scenario which is increasing in importance across the world as the number of high-speed rail lines increases and train operators aim to offer an attractive working environment to their passengers. These requirements mean that handover between cells has to be possible without interruption – in other words, with imperceptible delay and packet loss for voice calls, and with reliable transmission for data services.
This documents will cover basic LTE principles along with some brief impression about LTE features. Additionally, LTE Link Budget, LTE Coverage & Capacity Planning and Cell Radius calculation methodology have been depicted comprehensively in this document.
Overview on LTE implementation using XILINX FPGA Graduation Project
Higher Institute of Engineering and Technology - Arish
2016-2017
Supervised by
Dr. Abdelfatah Saad
Eng. Abdelrhman Ahmed
2016-2017
Orthogonal Frequency Division Multiplexing, OFDM uses a large number of narrow sub-carriers for multi-carrier transmission to overcome the effect of multi path fading problem. LTE uses OFDM for the downlink, from base station to terminal to transmit the data over many narrow band careers of 180 KHz each instead of spreading one signal over the complete 5MHz career bandwidth. OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates.
The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions. Channel equalization is simplified. The low symbol rate makes the use of a guard interval between symbols affordable, making it possible to eliminate inter symbol interference (ISI).
"Visu" de fósiles para profesores
Fotografías de fósiles comunes en los examenes prácticos para profesores
Pictures for the identification of common fossils in the practical examinations for teachers.
Low Peak to Average Power Ratio and High Spectral Efficiency Using Selective ...theijes
A low complexity peak to average power ratio (PAPR) reduction scheme for orthogonal frequency division multiplexing (OFDM) systems is proposed. All pass filters technique used PAPR is reduction but small amount of reduction, So use Selective Mapping (SLM) technique reduce PAPR and SNR increases.
Matlab Based Decimeter Design Analysis Wimax Appliacationiosrjce
A Digital down Converter (DDC), which is basically used to convert an intermediate frequency (IF)
signal to its baseband form, forms an integral part of wireless receivers. The major functional blocks of a DDC
constitute a mixer, Numerically Controlled Oscillator (NCO) and an FIR filter chain. In this paper, We can
comparison of two window and see the costs of all Window filters
Digital Implementation of Costas Loop with Carrier RecoveryIJERD Editor
Demodulator circuit is a basic building block of wireless communication. Digital implementation of
demodulator is attracting more attention for the significant advantages of digital systems than analog systems.
The carrier signal extraction is the main problem in synchronous demodulation in design of demodulator based
on Software Defined Radio. When transmitter or receiver in motion, it is difficult for demodulator to generate
carrier signal same in frequency and phase as transmitter carrier signal due to Doppler shift and Doppler rate.
Here the digital implementation of Costas loop for QPSK demodulation in continuous mode is discussed with
carrier recovery using phase locked loop.
An Adaptive Approach to Switching Coded Modulation in OFDM System Under AWGN ...ijsrd.com
In this paper we have studied the OFDM for different Quadrature amplitude modulation technique (QAM) The scatter plot and their output signal to noise ratio, dependent bit error rate variation is analyzed for every type of modulation in OFDM. After observing the BER for each SNR in the system, switching threshold range has been prepared and now system is ready to face the Adaptive coded modulation (ACM).The results shows the switching of modulation technique.
Efficient Design of Higher Order Variable Digital Filter for Multi Modulated ...IJTET Journal
The electrocardiogram (ECG) analysis is commonly used technique in clinical examination proposes a method of designing reconfigurable warped digital filter with various low-pass, high-pass, band-pass and band-stop responses. The warped filter is obtain by replacing each element interruption of a digital filter with an all exceed filter. It is widely used for various video and audio processing applications. Warped filters require first-order all pass conversion to obtain low-pass and high-pass responses, and by using second-order all pass conversion to obtain variable band-pass and band-stop responses. To overcome this drawback, proposed method combines warped filters with the coefficient decimation technique. In VLSI circuits in order to reduce hardware cost Command Signals Decoder (CSD) based shift-and-add approach is used for multiplication. It offers extensive savings in opening count and power utilization more than other approaches.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Ber performance of ofdm with discrete wavelet transform for time dispersive c...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
Abstract (11Bold) : — In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR. Keywords (11Bold) –64 QAM, BPSK, OFDM, PDF, SNR.
18. Simulations Parameters WINNER C2 NLOS User Velocity=50 Km/h Coherence Bandwidth=680.27 KHz Coherence Time=5.8 ms Channel Perfect Channel Estimation MMSE Equalizer Turbo Coding, Code rate ½, [G1,G2]=[11111,10001] Coding QPSK Modulation 12 Chunk Width 4 SCs per Block 128 No of SCs per User (K) 1024 Total Number of SCs (M) 1.47ns Guard Interval 12.5ns Sampling Time 1/12.5ns Sampling Frequency 3.7GHz Carrier Frequency 80MHz Bandwidth
19.
20. Turbo Code performance over AWGN & Rayleigh Fading Channel BIFDMA & LFDMA Performance on AWGN Channel (1% Clipping) BIFDMA & LFDMA Performance on Rayleigh Fading Channel (1% Clipping)
21. Uncoded & Coded System Performance (Single User) Uncoded Vs Turbo Coded Performance for Single User on Rayleigh Fading Channel
32. Multi Access Interference (MAI) with Near Far Effect Multi Access Interference with Near Far Effect (8 Users)
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Editor's Notes
The Diff between the two modulations techniques, talking about the advantages of the SC-FDMA in the uplink The major advantage of using SC-FDE or SC-FDMA in the uplink is low PAPR ratio of the transmitted signal caused by DFT Precoding done at the transmitter. PAPR is basically the ratio between the peak powers to average power of the transmitted signal. PAPR is very important in relation with the power amplifier efficiency at the transmitter and in the amplifier the maximum efficiency is achieved when it operates at the saturation point. The low PAPR value will allow the amplifier to operate close to the saturation region.
T
In case of the AWGN BIFDMA and LFDMA are overlapping as both collects same diversity due to no frequency selectivity in the channel. They will experience the same channel. A little variation in the curve are due to the impact of non linearities in the system. In case of Rayleigh fading channel the schemes collects more diversity than AWGN channel due to frequency selectivity.But if we compare both, the BIFDMA collects more diversity than LFDMA as it is comprised of 4 subcarriers per block so it will be less affected by the channel.while in case of LFDMA it comprises of 128 subcarriers per block so its more affected by the channel
The coded performance is much better than Uncoded system. The coded system metigate with the channel errors and thus results in the low Bit error rate. In the uncoded system the three schemes curves almost overlapped but they differs on high SNR‘s due to the different diversity acheived by three schemes. In the coded system the Bit Error rates are low due to coding effect. While there is a difference in Bit Error rates in the schemes and the reason is that, IFDMA collects more diversity than BIFDMA, while BIFDMA collects more diversity than LFDMA.
Long term average Bit error rate for multiuser system is identical to single user Bit error rate because of no nonlinearities so there will be no out band interference.
Due to clipping the average energy of the signal is changed that can effect the BER so we have rescaled the clipped signal to prevent this and to see the major effects of ICI, MAI and DFT and Near Far.
The figure shows that as the clipping level is increased the performance becomes worse. This is expected as increasing the clipping level will cause increased non linearities and hence increased power leakage between adjacent sub carriers i.e. ICI. Rescaling ensures that the variation in BER with increased non linearities is only due to ICI and not due to any power variation of clipped signal with respect to the unclipped signal. It is noteworthy here that 10% clipping means clipping about 102 samples and 30% clipping means clipping about 307 samples of the total 1024 frequency samples of SC-FDMA symbol. Moreover the figure above also shows that the BIFDMA performs better than the LFDMA whether we have 10% or 30% clipping. This can be explained as the out of band radiation, caused due to non linear distortions produced by non linear amplifier, is dependent on the envelope of the input signal to the amplifier [15]. The envelope fluctuations of BIFDMA in turn are considerably lower than those of LFDMA when we have no over sampling and no windowing of the signal [6]. Thus these lower envelope fluctuations for BIFDMA may account for the relatively better
The Performance of DFT Precoded System is still better even in non linear environment as compared to the Non DFT Precoded System. In this section we analyze the performance of BIFDMA and LFDMA by introducing non linearities using two different clipping levels (10% & 30%). The figure shows the change in BER of BIFDMA and LFDMA at 10 % and 30 % clipping in presence of DFT and Non DFT Precoding. The BER of the Non DFT Precoded System is higher than that of DFT Precoded System due to the fact that the absence of DFT Precoding results in higher envelope fluctuations that would ultimately cause higher out of band interference. Furthermore the BER for BIFDMA is lower as compared to LFDMA as it has comparatively lower envelope fluctuations [6]. Another reason for the low BER for DFT Precoded system is the spreading of each data symbol over multiple subcarriers thus giving frequency diversity as mentioned before. The BER for the two schemes is higher for 30 % clipping
The figures above clearly indicate that increasing the number of users would worsen the BER performance for both BIFDMA and LFDMA. Again rescaling makes sure that any variation in the long term BER of multiple users relative to BER of single user is purely due to multi‐access interference. Increasing the number of users in multiuser non linear system should increase the multi‐access interference which in our case holds true but the variation in BER for different number of users and that for single user is not that evident from the figures above. More over the degradation
to the base station than the others. In this situation the user that is near to the base station will be receiving higher power than the ones far from it. In figure we have analyzed the near far effect in a system having eight users. In this scenario we have one user that is far away from base station while the rest of others are near to it. The affected user (farther from the BS) has been assigned 5dBs less energy as compared to the rest of seven users while we have introduced non linearities in our system by clipping 30% of the samples in the signal.
The performance of turbo code over AWGN channel is much better as compared to the fading channel. Moreover owing to the fact that there is no frequency selectivity in AWGN channel both the BIFDMA and LFDMA collects same frequency diversity and hence BER curves for both almost fall over each other. In case of fading channel however BIFDMA performs better than LFDMA owing to its ability to collect more frequency diversity. Non linearities on the other hand cause slight deviations in the BER curves for the two schemes in both AWGN and fading channel due to out of band interference resulting from non linearities. • In linear environments, the BER performance of single user is identical to the long term BER performance of multiple users because of lack of out of band interference as is the case in non linear environments. IFDMA performs the best in terms of BER which is followed by BIFDMA and then LFDMA. This is because of the ability of IFDMA to achieve more frequency diversity than the other two schemes. • DFT Precoding is mainly intended to keep the PAPR of the signal to a lower level and hence to ensure efficient use of HPA. However DFT Precoded system also shows an improvement in BER performance compared to non DFT Precoded system owing to the frequency diversity gain in frequency selective channels caused by spreading of each data symbol over multiple subcarriers. • BIFDMA and LFDMA perform differently in terms of their BER performances for a single user, in linear environments and in non linear environments. The reason for this difference in BER performance is the ICI that is caused due to the non linearities in the system. The ICI increases as the clipping percentage is increased that result in higher non linearities. This is evident from increased difference in the BER compared to linear case. • In non linear environments, DFT Precoded systems again have better BER performance compared to non DFT Precoded systems. The reason for this is the reduced PAPR caused by DFT Precoding which reduces not only envelope fluctuations but also reduces influence of out of band radiations caused by non linearities. Similarly BIFDMA also performs better compared to LFDMA in non linear environments, again due to lower degrades the BER performance of multiuser system compared to single user system. As the number of users is increased the BER performance worsens due to increased MAI. • In the multi‐user system with non linearities, the near far effect is evident when few users with high power (near to base station) creates interference for the users that are far away from the base
The performance of turbo code over AWGN channel is much better as compared to the fading channel. Moreover owing to the fact that there is no frequency selectivity in AWGN channel both the BIFDMA and LFDMA collects same frequency diversity and hence BER curves for both almost fall over each other. In case of fading channel however BIFDMA performs better than LFDMA owing to its ability to collect more frequency diversity. Non linearities on the other hand cause slight deviations in the BER curves for the two schemes in both AWGN and fading channel due to out of band interference resulting from non linearities. • In linear environments, the BER performance of single user is identical to the long term BER performance of multiple users because of lack of out of band interference as is the case in non linear environments. IFDMA performs the best in terms of BER which is followed by BIFDMA and then LFDMA. This is because of the ability of IFDMA to achieve more frequency diversity than the other two schemes. • DFT Precoding is mainly intended to keep the PAPR of the signal to a lower level and hence to ensure efficient use of HPA. However DFT Precoded system also shows an improvement in BER performance compared to non DFT Precoded system owing to the frequency diversity gain in frequency selective channels caused by spreading of each data symbol over multiple subcarriers. • BIFDMA and LFDMA perform differently in terms of their BER performances for a single user, in linear environments and in non linear environments. The reason for this difference in BER performance is the ICI that is caused due to the non linearities in the system. The ICI increases as the clipping percentage is increased that result in higher non linearities. This is evident from increased difference in the BER compared to linear case. • In non linear environments, DFT Precoded systems again have better BER performance compared to non DFT Precoded systems. The reason for this is the reduced PAPR caused by DFT Precoding which reduces not only envelope fluctuations but also reduces influence of out of band radiations caused by non linearities. Similarly BIFDMA also performs better compared to LFDMA in non linear environments, again due to lower degrades the BER performance of multiuser system compared to single user system. As the number of users is increased the BER performance worsens due to increased MAI. • In the multi‐user system with non linearities, the near far effect is evident when few users with high power (near to base station) creates interference for the users that are far away from the base
been able to assess the performance of IFDMA in non linear environments. In future the simulations can be carried out in presence of pulse shaping to have more realistic comparisons of the three mapping schemes in linear and non linear environments. Threshold clipping has been used to model the amplifier non linearities in this thesis work which can be replaced by more sophisticated non linearity models like the Rapp model. The impact of carrier frequency offset (CFO) and Doppler can also be included to in the future research work. Finally the channel scenario being used in this thesis work is the WINNER C2 NLOS. It can be an interesting option to use other channel scenarios.