Catalin Lacatus

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In this paper, we present an adaptive algorithm for interference avoidance, which can be applied in a distributed manner by active users in a CDMA wireless system to obtain optimal codewords and powers for specified target signal-to-interference plus noise ratio (SINR). The algorithm is derived using a game-theoretic approach in which separable cost(More)
The paper presents a distributed algorithm for joint codeword and power adaptation in the uplink of a code division multiple access (CDMA) system, in which users sequentially adjust codewords and powers using gradient-based updates to maximize their individual spectral efficiency subject to constraints on the signal-to-interference plus-noise ratios (SINR).(More)
A definition of total weighted square correlation (TWSC) for an overloaded multicellular synchronous DS-CDMA system in the presence of multipath on the uplink is introduced. We assume the channel state information is known perfectly both at transmitter and receiver. The optimum solutions for minimizing TWSC are the orthogonal generalized WBE (Welch bound(More)
The paper presents a distributed algorithm that allocates the minimum user powers for the optimal codewords in the uplink of a code division multiple access (CDMA) system. The user cost function will be the user power written as a convex function of user codeword for a defined signal-to-interference plus-noise ratios (SINR) target. The optimization problem(More)
— The paper presents an interference avoidance algorithm for codeword and power adaptation in the uplink of a Code Division Multiple Access (CDMA) system with variable number of active users. The algorithm tracks changes in the system configuration, and transitions incrementally from one optimal point corresponding to a given number of active users to a new(More)
The paper presents a new approach of optimal spectrum and power allocation for orthogonal frequency-division multiplexing (OFDM) modulation schemes. The algorithm is implemented using a parallel processing method, where each transmitted bit will minimize its cost functions, by choosing the spectrum and powers that suit better the interference pattern. The(More)