| Abstrakt: |
The paper deals with research into use of wideband signals with direct spectrum spreading for reference signal formation in adaptive antenna arrays that work according to the mean squared error criterion. It is shown that in implementing the mean squared error criterion for adaptive antenna arrays in telecommunications, a problem arises of reference signal formation, especially in multipath propagation conditions. It is proposed to use for reference signal formation wideband signals with direct spectrum spreading with help of pseudo-noise coding sequences. It is stressed, that such sequences can be derived from a certain order primitive polynomials. Proposed procedure envisions use of RAKE scheme for establishing multipath propagation components delays to generate the reference signal for each of these components. With use of computer simulation methods, it is confirmed that if delays of multipath components are determined and, respectively, reference signals for each component are formed, adaptive antenna array is capable effectively extract multipath components with high SNR, even if shift of components one from the others is only one chip of the coding sequence. It is confirmed that this quality is related to the unique autocorrelative properties of pseudonoise sequences derived from the primitive polynomials of a certain order. It is further proposed to subject the multipath components, separated due to adaptive antenna array performance, to a weighted addition with compensation of relative delays and with account of the separate components SNR. It is stressed that proposed approach permits effectively implement the technology known as total MIMO. Further research is suggested to be concentrated on studying modulation impact of the transmitted signal on functioning of adaptive antenna arrays that implement proposed solutions. [ABSTRACT FROM AUTHOR] |
