Differential space-time modulation (DSTM) for multiple antenna communication systems has been recently proposed for frequency-nonselective fading channels. In broadband multirate systems, frequency-selective fading may occur. In this paper, the DSTM in frequency-selective fading channels is considered. A linear equalizer for the DSTM is proposed over frequency-selective fading channels. Further...

In this paper we introduce a new 2D modulation technique called OTFS (Orthogonal Time Frequency & Space) that transforms information carried in the Delay-Doppler coordinate system to the familiar time-frequency domain utilized by traditional modulation schemes such as OFDM, CDMA and TDMA. OTFS converts the fading, time-varying wireless channel into a non-fading, time-independent interaction rev...

in this paper the problem of minimizing the total transmitting power subject to a fixedtotal bit rate in ofdm systems is considered. upper bounds on transmitting power and bit rate ofeach subcarrier can also be taken into account. in practice, the number of bits of each subcarriershould be integer and nonnegative. in this paper an analytical optimal solution is derived for thecase of assuming t...

The bandwidth efficient modulation format OQPSK is implemented up to now merely in mobile radio systems which do employ spread spectrum techniques, i.e. it is not used in narrow band systems. This is due to the fact, that, in spite of its reduced performance degradation in non-linear channels in comparison to other linear modulation formats, for OQPSK no receivers were derived up to now, which ...

250 Abstract—Trellis coding combined with expanded signal sets has been considered in this paper to improve error performance over uncoded modulation. New communications services have created the demand for highly linear high power amplifiers (HPA's). Traveling Wave Tubes Amplifiers (TWTA) continue to offer the best microwave HPA performance in terms of power efficiency, size and cost, but lag...

A blind (non-data aided), open loop, joint frequency offset and delay estimation algorithm for a linearly modulated signal in additive stationary noise is developed by exploiting the cyclostationarity of the signal. By considering the sample cyclic autocorrelation function of the received signal and the probability distribution of the estimation error, a general linear model representation of t...

orthogonal frequency division multiplexing (ofdm) has become a promising method for many wireless communication applications. however, one main drawback of ofdm systems is the high peak-to-average power ratio (papr). selected mapping (slm) is a well-known technique to decrease the problem of high papr in ofdm systems. in this method, transmitter is obliged to send some bits named side informati...