The paper presents the construction of encoders and decoders turbo codes with different number of states. Simulation results of the transmission quality of turbo codes were presented. Decoders for turbo codes have been tested with a fixed number of iterations and with mechanisms that reduce the number of iterations. The data were transmitted in an Outdoor to Indoor & Pedestrian B environment for a data rate of 384 kbps. The SOVA algorithm was used for turbo decoders.

Multi-carrier code division multiple access (MC-CDMA) technique is a combination of two radio access techniques: CDMA and orthogonal frequency division multiplexing and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface. It also presents encoders and decoders of turbo codes which were used in simulation of the MC-CDMA technique. Two turbo codes with 8-state recursive systematic convolutional were used in the simulation. The simulation results of the transmission quality in additive white Gaussian noise (AWGN) channel presented in the paper show bit error rate and frame error rate performance of MC-CDMA technique with the turbo codes and allow for comparison the performance of both turbo codes.

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The paper presents issues related to the cooperative communication in wireless networks. Cooperative communication involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. It is also possible to use several different data transmission standards. The paper presents the methods used to implement cooperative communication. The types of cooperative communication networks are also presented.

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