Mimo System Channel Correlation And The Closed-loop Space-time Algorithm

In recent years, with the rapid development of mobile communication and emergingservices, the demands for the limited frequency resource are booming. It is becoming asignificant goal in mobile communication to use limited spectrum resource to achievehigher system capacity. Meanwhile, MIMO (Multiple In, Multiple Out) which utilizesmultiple antennas to transmit and receive has drawn considerable attention for its highspectrum efficiency. There is a popular view that MIMO will likely be a key technique innext-generation mobile communication system.So far, many works have point out that times of capacity can be achieved by MIMOtechnique, most of which make an assumption of independent and identically distributedi.i.d. fading. However, in real propagation environments, the fades are not independentdue, for example, to insufficient spacing between antenna elements. The impact of channelcorrelations on the capacity of MIMO systems has been discussed in many recent papers.All studies point out that fading correlations degrade, sometimes severely, the MIMOergodic capacity when compared to the ideal case of independent identically Rayleighdistributed (IID) channels. The thesis beginning with MIMO system emphasizes theresearch of impact of channel correlations on capacity and BER in STBC system.Moreover, it is significant that the validation to theoretic analysis is done with real dadafrom MIMO experimental systems associated with 863 plan. In addition, the thesisanalyzes information theoretic MIMO capacity, simulating average capacity of severaltypical systems ,such as SISO,MISO,SIMO,MIMO ,comparing the difference amongthem and discussing the relationship between the capacity and the variation of antennanumber. We make a research on space-time algorithm in close loop MIMO system,detailing a scheme of optimizing transmit antenna in STBC systems. The rest part of thethesis details software platform of MIMO experimental system, deep analyzing the datafrom hardware system, including the probability density function (pdf) of channelcoefficient's envelops, channel correlations at transmitter/receiver side. Comparing the pdfabove with that of ideal Rayleigh distribution and Ricean distribution. Putting the realdata's correlations into theoretic simulation for STBC system to validate whether the BERcurve from real data can match the theoretic BER curve.