This paper presents a novel adaptive direct-sequence code-division multiple-access (DS-CDMA) slotted-ALOHA (S-ALOHA) packet random-access scheme with transmitter-based spreading codes for mobiles. It is aimed at improving throughput and message delay delivery when traffic load values below the saturation point of the conventional DS-CDMA S-ALOHA system are sensed in the channel. For this purpose, one mobile-station (MS) and two base-station (BS)-assisted algorithms are envisaged to control the change of the transmission rate according to the traffic load. These algorithms revealed that the optimum behavior, obtained using a Markov chain model, may almost be reached at a low-complexity cost. A traffic model based on a realistic statistical length distribution of the messages illustrates how the delay delivery can be greatly reduced with the proposed algorithms. Finally, the impact of forward-error-correction (FEC) coding on the adaptive system is also studied.
CitationSallent Roig, J.O; Agustí Comes, R. A proposal for an adaptive S-ALOHA access system for a mobile CDMA environment. IEEE Transactions on Vehicular Technology, 1998, vol. 47, núm. 3, pàg. 977-986
All rights reserved. This work is protected by the corresponding intellectual and industrial property rights. Without prejudice to any existing legal exemptions, reproduction, distribution, public communication or transformation of this work are prohibited without permission of the copyright holder. If you wish to make any use of the work not provided for in the law, please contact: email@example.com