Mimo ofdm by abhishek pandey

  • View

  • Download

Embed Size (px)

Text of Mimo ofdm by abhishek pandey


2. In this project we show the performance of MIMO-OFDMsystem in Rayleigh Fading Channel MIMO-OFDM system is very popular technique for mobilecommunication now a days .We compares Ergodic andOutage Capacity , with taking various numbers ofTransmitting and Receiving antennas and variousperformance measures such as SNR, BER etc. MIMO-OFDM, Ergodic Capacity, BER, SNR Outage Capacity 3. Ever-increasing demands in communication industrytowards wireless Challenges:- to improve spectral efficiency- efficient bandwidth utilization- economical Signal Processingalgorithms- high speed processing h/w 4. - Multiple i/p multiple o/pantenna array- Used to increase data rates,improve capacity and BER(bit error rate) of the systemDiagram of a MIMO wireless transmissionsystem. - Typically used with OFDM soas to suit best needs in nextgeneration comm. i.e. 4G 5. SU-MIMO (Single User - MIMO)this utilizes MIMO technology to improve the performance towards a single user. MU-MIMO (Multi User - MIMO)this enables multiple users to be served through the use of spatial multiplexing techniques. 6. Definition The first OFDM schemes presented in 1966 Development of OFDM over years 7. - Converts a frequency selectivechannel into a parallel collectionof frequency flat sub channels- Orthogonal frequency divisionmultiplexing uses bandwidthefficiently- Improves multipath fading issues- Reduces the effect of ISI (inter-sub carrier interference) OFDM System block Diagram 8. It distributes the data over a large number of carriers thatare spaced apart at precise frequencies.This spacing provides the "orthogonality" in thistechnique which prevents the demodulators from seeingfrequencies other than their own. 9. Two conditions must be considered for theorthogonality between the subcarriers. Each subcarrier has exactly an integer number of cycles in the FFT interval. The number of cycles between adjacent subcarriers differs by exactly one. 10. STTD (space time transmit diversity) SM (spatial multiplexing) AMC (adaptive modulation & coding) with modulation techniques such asQPSK, 16-QAM, 64-QAM H-ARQ (Hybrid automatic repeat request) Shared access and MAC (medium access control) used for schedulingpacket access with Qos 11. Coupling MIMO and OFDM concepts to improve data rates indownlink of wireless communication networks. Analyzing the performance and building a prototype ofWireless WANS using MIMO-OFDM Use of adaptive loading algorithms such as Chows andCompellos. Employing SVD (singular value decomposition) method toincrease the performance incase of MIMO 12. Survey, Implementation and performance analysis of existing MIMO Learning s/w and h/w Developing efficient algorithms Software synchronization development Various candidate coding and receiver strategies Identification of Equipment Implementation of prototype 13. The results obtained from these tests indicate very goodperformance for the MIMO-OFDM prototype. Concept is proving to be very robust in highly dispersivechannels Cost reduction is being investigated through various methods Simulation results show that at any given BER the adaptiveSISO system will be outperformed by the adaptive MIMOsystem Other future work areas involve the improvement of MIMOprocessing complexity and practical implementation issues.