1 / 30

Performance of LTE Uplink in Impulsive Noise Environment

This project aims to analyze the performance of LTE uplink over a frequency selective fading channel in an impulsive noise environment. The study will consider the impact of impulsive noise on the system and propose efficient techniques to mitigate its effects.

jdahl
Download Presentation

Performance of LTE Uplink in Impulsive Noise Environment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Projects (1) Performance of LTE uplink over frequency selective fading channel in impulsive noise environment (2) Performance of LTE downlink over frequency selective fading channel in impulsive noise environment. (3) Performance of LTE uplink in impulsive noise environment and non-fading channel.(4) Performance of LTE downlink in impulsive noise environment and non-fading channel(5) Channel estimation of OFDM system

  2. LTE (4G)

  3. Long Term Evolution (LTE) • LTE commonly marketed as 4G LTE. It is a standard for wireless communication of high-speed data for mobile phones. • The main requirements for the new access network are high spectral efficiency, high peak data rates, short round trip time as well as flexibility in frequency and bandwidth. • In LTE, both Frequency-division duplex (FDD) and time-division duplex (TDD) transmission are supported.

  4. Long Term Evolution (LTE) • Orthogonal Frequency Division Multiple Access (OFDMA) is considered the most appropriate scheme for achieving high spectral efficiency for the LTE downlink. • Since, OFDMA suffers from power distortion that may be particularly troublesome in uplink transmissions where excessive complexity in user terminal is an issue. Therefore, for the uplink, the LTE employs SC-FDMA due to its low PAPR properties compared to OFDMA. • These multiple access solutions provide orthogonality between the users, reducing the interference and improving the network capacity.

  5. Long Term Evolution (LTE) Figure 2

  6. Downlink: OFDMA Figure 3. OFDMA system model for downlink.

  7. Problems of OFDMA • Peak to average power ratio. When the independently modulated subcarriers are added coherently, the instantaneous power will be more than the average power. Fig. High peaks in OFDM signal generated by summing multiple sinusoids

  8. Problems of OFDMA Such high peaks will produce signal that goes into nonlinear region of operation of the power amplifier (PA) at the transmitter, thereby leading to nonlinear distortions and spectral spreading. High peak-to-average-power ratio (PAPR), requiring linear transmitter circuitry, which suffers from poor power efficiency.

  9. Problems of OFDMA (2) Carrier frequency offset. The ability of OFDMA systems to achieve higher data rates and facilitate bandwidth friendly communication is impaired by the necessity of accurate frequency synchronization between the receiver and the transmitter. With frequency deviation, the sub-carriers will no longer be orthogonal causing inter-carrier interference.

  10. UpLink: SC-FDMA System Figure 4. SC-FDMA system Model for UPlink

  11. Class-A Impulsive Noise

  12. Class-A Impulsive Noise • Sources for man-made noise are e.g. radio frequency emissions from all sorts of electronic devices used in all daily life, automotive ignition noise, and power transmission line. • The white Gaussian noise component is presented in the class-A noise model to describe the influence of thermal noise which is naturally present in the real physical receiver. • The impulsive noise is defined by two parameters which are the impulsive index A and the Gaussian factor Γ. As A decreases the noise becomes more impulsive. On the other hand, As A increases the noise becomes more Gaussian.

  13. Class-A Impulsive Noise • For A=0.1: • For A=0.01:

  14. Class-A Impulsive Noise • The class-A impulsive noise has a probability density function (pdf): • Where: • Ais called the impulsive index of noise. • is given by : • Where: • is the mean variance of class A impulsive noise. • Гis the ratio of the mean power of the Gaussian noise component to the non- Gaussian impulsive noise component .

  15. Impulsive Noise PDF • The impulsive noise PDF is only considered for m=0,1,2.

  16. Projects (6) Resource allocation for device to device communications

  17. 5G: versus Conventional Cellular Networks

  18. Device to Device Communications

  19. Resource Allocation Algorithms

  20. Device to Device Communications

  21. Projects (7) Multi-Source cooperative communication with interference cancellation in amplify and forward protocol (8) Multi-Source cooperative communication with interference cancellation in decode and forward protocol (9) Incremental Hop selection scheme for amplify and forward relaying (10) Incremental Hop selection scheme for decode and forward relaying

  22. Cooperative Communication with Relays

  23. Cooperative Communication with Relays

  24. Relay Transmission Strategies • Decode and Forward • Amplify and Forward • Compress and forward • Most popular are: Decode and Forward (DF) and Amplify and Forward (AF)

  25. Decode and Forward (DF) • During the first interval, the transmitter sends the signal to the relay: • The relay decode and re-encode the received signal and during the second interval it forwards it to the destination:

  26. Amplifyand Forward (AF) • During the first interval, the transmitter sends the signal to the relay: • relay multiplies its received signal by a coefficient (Gain) and during the second interval it forwards it to the destination.

  27. Multi-Source cooperative communication with interference cancellation

  28. Incremental Hop selection scheme

  29. Cooperative Communication with Relays

More Related