In this article, we concerned with the performance of high rate space time block code (STBC) scheme for Frequency selective fading Environment. Due to large channel delay spread in Frequency selective channel inter symbol interference (ISI) occurred. In high rate STBC, ISI occurs due to loss of „quasi – static‟ assumption and Classical Zero forcing (ZF) receiver produces error floor in Bit erro...

--A novel technique to enhance the robustness of space–frequency block coded (SFBC) orthogonal frequency-division multiplexing (OFDM) systems. The proposed system shapes the channel matrix of a frequency-selective fading channel into a piecewise flat--fading over each block of two adjacent subcarriers. Analytical and simulation results show that the proposed scheme substantially outperforms the...

In a frequency-selective fading channel, the performance of non-spread-spectrum singlecarrier (SC) transmission degrades significantly due to severe intersymbol interference (ISI). The joint use of space–time transmit diversity (STTD), receive antenna diversity and frequency-domain minimum mean square error (MMSE) equalisation in non-spread SC transmission is studied. Space–time encoding and de...

Orthogonal multi-carrier direct sequence code division multiple access (orthogonal MC DS-CDMA) is a combination of time-domain spreading and orthogonal frequency division multiplexing (OFDM). In orthogonal MC DS-CDMA, the frequency diversity gain can be obtained by applying frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion to a block of OFDM symbols and can...

We introduce a new family of space–time trellis codes that space–time block codes as building blocks in our new trellis codes. These codes combine set partitioning and a super set of space–time block codes in a systematic way to provide full diversity and improved coding gain.. It is also possible to maintain a tradeoff between coding gain and rate.. Simulation result (i.e. frame error rate) sh...

This paper presents a maximum a posteriori (MAP) equalizer for bandlimited signals on frequency selective fading channels. A key contribution is the way in which the state-space of the MAP trellis is expanded for the purpose of joint channel estimation and equalization. The fading channel is estimated by coupling minimum mean square error techniques with the expanded MAP trellis. The symbol-by-...

OFDM renders multipath channels with nite memory equivalent to parallel at fading subchannels, over which equalization amounts to simple phase compensation. If the channel status information is known at the transmitter side, optimal power loading across subchannels is possible. Users mobility, time and carrier asynchronism introduce variations in the equivalent channel impulse response setting ...

In this paper, we investigate the performance of transmit diversity technique operating in IS-136 T D M A systems where the Doppler frequency can be as high as 184Hz. Transmit diversity transforms a pat fading channel into a frequency selective fading channel, thus we use finite length decision feedback equalizers to estimate the desired signal at the receiver. The channel parameters are traine...