In this paper, we propose clipping noise cancellation scheme using compressed sensing (CS) for orthogonal frequency division multiplexing (OFDM) systems. In the proposed scheme, only the data tones with high reliability are exploited in reconstructing the clipping noise instead of the whole data tones. For reconstructing the clipping noise using a fraction of the data tones at the receiver, the...

This paper considers the physical layer security of frequency hopping (FH) systems. Mainly due to the collision effect among different users, the spectral efficiency of the conventional FH is very low. To overcome this limitation, in this paper, we first propose a general collision-free frequency hopping (CFFH) scheme based on secure spectrum access control; Second, we incorporate the CFFH sche...

We propose an orthogonal frequency division multiplexing frequency division multiple access (OFDMA) system with an adaptive multiple antenna transmission scheme for future wireless communkatlon systems. In the system, both a transmit diversity scheme with high order modulation and a spatial multiplexingscheme with low order modulation are employed for the given spectral efilciency, between whic...

Wireless communication is very vast and having lot of ideas for increasing capacity and BER performance. This paper describes the modeling and performance improvement of Wireless Regional Area Network (WRAN) ( IEEE 802.22 ) through different Forward Error Correction (FEC) Techniques.In this paper we have used different coding techniques over different modulation scheme. For simulation , we have...

Most standards for the forthcoming beyond 3G (B3G) and 4G technologies state Orthogonal Frequency-Division Multiple Access (OFDMA) as a very promising candidate to be used as a digital modulation scheme. OFDMA combines multiple access techniques with Adaptive Quadrature Amplitude Modulation (AQAM) to maximize system performance while keeping the errors below a certain target. In order to achiev...

In this paper we show how a fundamental result from information theory can be used to calculate the aggregate channel capacity in the uplink of an access point or a base station. The fundamental limits for this cell capacity provide an upper bound for any practically implementable multiple-access scheme. The capacity loss due to various implementation constraints is evaluated and a method for a...

In this paper, we investigate an efficient user selection and sub-band allocation algorithm in which each user transmits two-step partial CQI to reduce the amount of feedback in multi-user downlink OFDMA systems. Simulation results show that we can greatly reduce the feedback rate at the expense of negligible performance degradation compared to the full CQI feedback schemes or that we can great...

Radio over Fiber (RoF) Technology is integration of radio emission in optical fibre transmission at intervals network infrastructures that's thought of to be cost-efficient, sensible and comparatively versatile system configuration for long-haul transport wireless signals. This project propose a Next generation PON design supports RoF and OFDMA signal integration while not WDM lasers, and demon...

In recent years, large usage of wireless networks puts forward challenge to the utilization spectrum resources, and it is significant improve system sum data rates in premise fairness. However, existing algorithms have drawbacks efficiency maximize orthogonal frequency division multiple access (OFDMA) systems fairness threshold. To address issue, a novel artificial bee colony algorithm with upd...

In this paper, a resource allocation algorithm is proposed for OFDMA relay networks with inter-cell interference coordination. Simulation results show the effectiveness of the proposed algorithm.