Performance comparisons between greedy and lagrange algorithms in adaptive MIMO MC-CDMA systems

This paper describes two algorithms for adaptive power and bit allocations in a multiple input multiple output multiple-carrier code division multiple access (MIMO MC-CDMA) system. The first is the greedy algorithm, which has already been presented in the literature. The other one, which is proposed by the authors, is based on the use of the Lagrange multiplier method. The performances of the two algorithms are compared via Monte Carlo simulations. At present stage, the simulations are restricted to a single user MIMO MC-CDMA system, which is equivalent to a MIMO OFDM system. It is assumed that the system operates in a frequency selective fading environment. The transmitter has a partial knowledge of the channel whose properties are measured at the receiver. The use of the two algorithms results in similar system performances. The advantage of the Lagrange algorithm is that is much faster than the greedy algorithm. ©2005 IEEE

Understanding and analyzing the performance of MIMO systems from the microwave perspective

Multiple input multiple output (MIMO) wireless systems use multiple element antennas at the transmitter and receiver to offer improved capacity over conventional single antenna systems in a rich scattering environment. In this paper, the microwave perspective of operation of MIMO system is given. Following the new interpretation of operation, an electromagnetic model is introduced to assess the MIMO system transmission capacity. The proposed model is shown to provide good agreement with reported results in the literature.