Optimum modulation and coding for maximum coverage-Capacity In Cellular CDMA systems

The aim of this report is to present the results of the research project # 8/424 sponsored by the College of Engineering Research Center. The project objective is to study the effect of changing signal alphabet and error correcting codes on coverage and capacity of Cellular CDMA system employing single-user detection. For limited transmitted power, in-cell interference limits cell coverage. M-ary Quadrature Amplitude Modulation is considered and outage probability is calculated using the Guassian approximation for powers received at the base station. The number of active users is considered as a random variable with Poisson distribution. The results show that even without the use of error correcting codes, higher level modulations with M= 4,8,16 and 32 outperform binary modulation. Error correcting codes can further enhance coverage and capacity

A New MSE Approach for Combined Linear-Viterbi Equalizers

Combined linear-Viterbi equalization (CLVE) is a technique that employs a linear pre-filter in conjunction with the Viterbi algorithm (VA) to mitigate the effects of intersymbol interference. The aim of the linear pre-filter is to shape the original channel impulse response to some shorter desired impulse response (DIR) in order to reduce the complexity of the VA. In this paper, we presentanewMSEbased approach for optimizing CLVEs. This approach takes advantage of the recent modifications to the VA which are suitable for channels having coarsely located coefficients. Specifically, the new approach has the flexibilityinchoosing the positions and optimizing the values of nonzero coefficients of DIR. As a result, it includes the conventional MSE-based approaches as a special case. Simulation results have been presented to illustrate the performance of proposed method

New MSE approach for combined linear-Viterbi equalizers

Combined linear-Viterbi equalization (CLVE) is a technique that employs a linear pre-filter in conjunction with the Viterbi algorithm (VA) to mitigate the effects of intersymbol interference. The aim of the linear pre-filter is to shape the original channel impulse response to some shorter desired impulse response (DIR) in order to reduce the complexity of the VA. In this paper, we present a new MSE-based approach for optimizing CLVEs. This approach takes advantage of the recent modifications to the VA which are suitable for channels having coarsely located coefficients. Specifically, the new approach has the flexibility in choosing the positions and optimizing the values of nonzero coefficients of DIR. As a result, it includes the conventional MSE-based approaches as a special case. Simulation results have been presented to illustrate the performance of proposed method