Multiplexing is a method by which multiple analog message signals or digital data streams, coming from different sources are combined into one signal over a shared medium. In this paper, we present an overview of different multiplexing techniques in bandwidth utilization. We focus on the three well-known multiplexing technique used in bandwidth utilization which are Frequency-Division Multiplex...

In a fast fading channel, the orthogonality of the two consecutive Space Time Block Codes (STBC)-Orthogonal Frequency Division Multiplexing ( OFDM) symbols will be destroyed and the received signals cannot be perfectly separated. TR(Tone Reservation) is a technique designed to combat this problem by reserving a number of carries(tone) in the frequency domain to generate a cancellation signal in...

In this contribution, we investigate the effect of carrier phase errors on the performance of orthogonal frequency division multiplexing (OFDM) and multicarrier code-division multiple access (MC-CDMA). We show that OFDM and MC-CDMA have essentially the same sensitivities to carrier phase errors. A constant carrier phase offset yields no degradation of the system performance. We show that OFDM a...

Space-frequency coded Orthogonal Frequency Division Multiplexing (OFDM) is capable of realizing both spatial and frequency-diversity gains in multipath multiple-input multipleoutput (MIMO) fading channels. This naturally leads to the question of variable allocation of the channel’s degrees of freedom to multiplexing and diversity transmission modes. In this paper, we provide a systematic method...

The high Peak to Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) and MIMO-OFDM systems reduces the system efficiency. In this paper, an extension of Tone Reservation (TR) method is introduced for PAPR reduction in Space Frequency Block Coded OFDM (SFBC-OFDM) systems. The proposed algorithm is based on a time domain kernel which is added to the signal of the anten...

Orthogonal Frequency Division Multiplexing (OFDM) is one of recent years multicarrier modulation used in order to combat the Inter Symbol Interference (ISI) introduced by frequency selective mobile radio channel. The circular extension data symbol, commonly referred as cyclic prefix key elements an OFDM transmission scheme. This paper study influence duration on BER performance OFDM-VCPL (Ortho...

This work explores the performances of Space-Time and Space Frequency Coded Orthogonal Frequency Division Multiplexing (OFDM) with simple two branches transmit diversity scheme. The combination of multiple-antenna and orthogonal frequency division multiplexing (OFDM) provides reliable communications over frequency selective fading channels. We focus on the application of space-time block codes ...

This paper presents a new model for systems beyond 3G of cellular communication techniques. The proposed scheme includes several new techniques: multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), and smart antennas (beamforming). The performance analysis was done in an interference-rich environment, and closed form expression for SINR was also determined. ...

Orthogonal Frequency Division Multiplexing (OFDM) is a well-known modulation technique for transmission of large amount of digital data with high data rate in both wired and wireless communication systems. High peak-to-average power ratio (PAPR) is the main problem of OFDM system which can be improved by using single carrier frequency division multiple access (SC-FDMA) technique. The simulation...