Hafez Hadinejad-Mahram

On the equivalence of linear MMSE chip-level equalizer and generalized RAKE

Several linear equalization schemes have been proposed for the downlink of direct-sequence code-division multiple-access systems. Previous numerical performance evaluation of such algorithms showed the equivalence of the linear minimum mean-square error chip-level equalizer and a slightly modified version of the generalized RAKE. In this letter, we establish this equivalence analytically.

Matched-filter bound for binary signaling over dispersive fading channels with receive diversity

The matched-filter bound (MFB) for continuously dispersive Rayleigh fading channels with receive diversity is derived. The treatment is quite general, as the case of discrete multipath channels with correlated fading is included in our model as a special case, and we impose no constraints with regard to the selectivity of the channel. It is assumed that a statistical characterization of the channel is available through its direction-delay-Doppler power spectral density. The Karhunen-Loe/spl grave/ve expansion for vector processes is used to describe the received signal. The MFB is analyzed with respect to several parameters characterizing the mobile radio channel, the waveform, and the antenna configuration.

Matched filter bound for space-time block coded MIMO systems in correlated multipath fading

The matched filter bound for space-time block coded multiple-input multiple-output systems in a frequency-selective Nakagami fading channel is derived for binary phase shift keying. Arbitrary correlation among the elements of the transmitter and the receiver antenna arrays is taken into account. Moreover, in the special case of Rayleigh fading the effect of the pulse shape is also considered. The resulting expressions allow for evaluation of the impacts of different system design parameters and the characteristics of the propagation environment on the bit-error rate performance of the system.

Joint sequential decoding and noncoherent multiuser detection for synchronous signaling over a flat fading channel

This paper considers the problem of joint multiuser detection and decoding of data transmitted over a frequency nonselective Rayleigh fading channel, where the detection is performed without previous knowledge of the channel coefficients. Both detection and decoding are carried out jointly by means of a sequential decoder. We derive a metric matched to the above problem which is based on the well-known Fano (1963) metric and discuss its properties. Using computer simulation, we evaluate the performance of a sequential decoder that uses this metric in conjunction with the stack algorithm. Our simulation results show that the proposed algorithm outperforms a receiver that uses optimum multiuser detection and optimum soft decision decoding as two separate steps, however at the cost of even larger time complexity.

Sequences and sequence pairs with imaginary correlation sidelobes

Time-discrete signals with good correlation properties are used in various applications in communications engineering. In this paper, the construction of quadriphase and 8-phase sequences and sequence pairs with purely imaginary aperiodic, periodic and odd-periodic correlation sidelobes is discussed. Using coherent detection, these imaginary sequences show perfect correlation properties if only the real part of the correlation function is used. Copyright

Matched filter performance of receive antenna arrays in dispersive Rayleigh fading channels

The matched filter bound for binary signaling in continuous Gaussian WSSUS channels with receive diversity is derived. The treatment is quite general as the case of discrete multipath channels with correlated fading is a special case of our results. Furthermore, we impose no constraints with regard to the selectivity of the channel, i.e. the channel may or may not be time, frequency, and space selective. It is assumed that a statistical characterization of the channel is available through its direction-delay-Doppler power spectral density. The derivation is based on using a discrete representation of the received signal obtained by the Karhunen-Loeve-expansion. Arbitrary propagation directions of the waves impinging at the antenna array can be taken into account. The behavior of the matched filter bound is analyzed with respect to the parameters characterizing the mobile radio channel and the properties of the antenna array, i.e. the number of sensors, the antenna pattern, and the array geometry.

Quadriphase and 8-phase sequences and sequence pairs with imaginary correlation sidelobes

In this paper, the construction of quadriphase and 8-phase sequences and sequence pairs with purely imaginary aperiodic or periodic correlation sidelobes is discussed.

Second-Order statistics of Closed-Loop Power Controller Signals in Multi-Path Rayleigh Fading Channels

The second-order statistics of power controlled signals in multi-path Rayleigh fading channels are considered. These statistics can be used e.g. in design and evaluation of channel estimation and channel coding schemes. The simulation results presented here provide a comprehensive comparison between the figures obtained with and without power control. The measures considered include the autocorrelation function and the power spectrum of the received signal, the autocovariance function of the signal power, and finally the mean and variance of the received signal power. The results are based on single-user link level simulations with a fixed-step power control scheme.