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Ofdm Systems

Synchronization in MIMO OFDM systems

Synchronization in MIMO OFDM systems

... (OFDM) systems is presented. It is well-known that multicarrier systems suffer from their high sensitivity to mismatches of transmitter and receiver oscilla- tor ...

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An Overview of PAPR Reduction Techniques in OFDM Systems

An Overview of PAPR Reduction Techniques in OFDM Systems

... OFDM is a very attractive technique for communications due to its spectrum efficiency and channel robustness. One of the serious drawbacks of OFDM systems is that the composite transmit signal can ...

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Adaptive Modulation and Coding Rate for OFDM Systems

Adaptive Modulation and Coding Rate for OFDM Systems

... For practical OFDM systems, the frequency spacing is less than the coherence bandwidth and the symbol time is less than the coherence time. This means that a receiver and pilot estimation pattern that take ...

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Semiblind channel estimation for MIMO–OFDM systems

Semiblind channel estimation for MIMO–OFDM systems

... MIMO–OFDM systems based on a specific and non-redundant precoding scheme, say, circular pre- coding, since the circular precoding allows channel esti- mation at the receiver and simplifies the encoding scheme ...

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OFDM systems design using harmonic wavelets

OFDM systems design using harmonic wavelets

... in OFDM systems is an important tool for increasing the power efficiency of HPA in digital communica- tion ...systems. OFDM symbols exhibit high peaks which may appear within the nonlinear ...

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Opportunistic Scheduling for OFDM Systems with Fairness Constraints

Opportunistic Scheduling for OFDM Systems with Fairness Constraints

... in OFDM systems has attracted a lot of research interest [26, ...diversity. OFDM has been used in several applications in cognitive ...is OFDM due to its inherent ...radio systems and ...

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Bit Loading Algorithms for Cooperative OFDM Systems

Bit Loading Algorithms for Cooperative OFDM Systems

... In this paper, we investigated resource allocation for coop- erative OFDM systems. Aiming at minimizing the total two- stage transmission power for a given transmission rate, we formulated the optimization ...

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Time and Frequency Synchronisation in 4G OFDM Systems

Time and Frequency Synchronisation in 4G OFDM Systems

... In this paper, fast and accurate timing and frequency synchronisation algorithms are proposed. The synchronisa- tion is a two-stage process. First, coarse timing and frac- tional frequency offset synchronisation are ...

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CHANNEL ESTIMATION FOR OFDM SYSTEMS WITH TRANSMITTER DIVERSITY

CHANNEL ESTIMATION FOR OFDM SYSTEMS WITH TRANSMITTER DIVERSITY

... The LMMSE channel estimation requires a large number of complex multiplications in OFDM systems that operate in channels with an exponentially decaying power delay profile. In this chapter, a low complexity ...

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An Improved Technique to Reduce ICI in OFDM Systems

An Improved Technique to Reduce ICI in OFDM Systems

... The researches at ICI reduction techniques for OFDM systems were begun in very early date. Among all the frequency offset reduction techniques like Frequency Domain Equalization [11], Time Domain Windowing ...

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Synchronization and channel estimation in MIMO OFDM systems

Synchronization and channel estimation in MIMO OFDM systems

... MIMO- OFDM systems which are ...for OFDM systems based on pilot arrangement are ...in OFDM- based systems have been published so ...

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Timing and Frequency Synchronization in Practical OFDM Systems

Timing and Frequency Synchronization in Practical OFDM Systems

... practical OFDM systems for downlink and uplink communications ...every OFDM burst to facilitate timing, frequency, and channel ...certain OFDM symbols are allocated to the ranging channel via ...

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PERFORMANCE ANALYSIS OF SPECTRUM SENSING IN OFDM SYSTEMS APPLICATIONS

PERFORMANCE ANALYSIS OF SPECTRUM SENSING IN OFDM SYSTEMS APPLICATIONS

... On the other hand, the pilot symbol-aided method uses the multiplexed pilot in the transmitted signal to estimate the channel. Recently, diverse orthogonal frequency division multiplexing (OFDM) systems ...

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Training Based Channel Estimation in MIMO OFDM Systems

Training Based Channel Estimation in MIMO OFDM Systems

... In this paper, we have considered the training based channel estimation for MIMO-OFDM systems. It is seen that there is ample scope for performance improvement even in the presence of the channel mismatch ...

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Joint CFO Estimation and Data Detection in OFDM systems

Joint CFO Estimation and Data Detection in OFDM systems

... for OFDM systems over frequency selective fast fad- ing ...communication systems, channels are frequency ...for OFDM systems over frequency selective channels is stimulated by this ...

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Low Complex PAPR Reduction Schemes for OFDM Systems

Low Complex PAPR Reduction Schemes for OFDM Systems

... Some researchers proposed nonlinear processing to reduce high PAPR, through which, the undesirable distortion generated by passing through DAC and HPA can be avoided. Companding is a technique that compresses the signal ...

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An Opportunistic Error Correction Layer for OFDM Systems

An Opportunistic Error Correction Layer for OFDM Systems

... We propose a novel cross layer scheme to reduce the power consumption of ADCs in OFDM systems. The ADCs in a receiver can consume up to 50% of the total baseband energy. Our scheme is based on ...

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Pulse shaping design for OFDM systems

Pulse shaping design for OFDM systems

... pulse-shaped OFDM with small overlap- ping factor K should be chosen, basically extending the symbol duration by up to half the symbol interval at maximum, ...for OFDM/W-OFDM systems described ...

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Design of FFT Processor for OFDM Systems

Design of FFT Processor for OFDM Systems

... Now a day, there is requirement of high speed multimedia transmission in wireless communication system. So, in order to the increase the speed we are using the FFT and IFFT designs in OFDM systems. In ...

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Resource allocation in MIMO-OFDM Systems

Resource allocation in MIMO-OFDM Systems

... filling algorithm. The simulation model accepts inputs as text or audio files, binary, sinusoidal, or random data. The channel simulation allows examination of common wireless multipath channel characteristics such ...

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