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This work proposes an analytical model to investigate the behavior of a radio link control (RLC) protocol on the forward link of a mobile radio system and to relate its performance to transmission design. As a reference case, a multicarrier DS-CDMA architecture employing Walsh and quasi-orthogonal channelization codes, similar to the current cdma2000 system, is considered. Jointly modelling the features of the data link layer and of the underlying physical channels, it is possible to identify the interaction between transmission parameters and the RLC protocol behavior. The latter is assessed by analysis, determining the RLC protocol goodput and the average delivery time suffered by a data unit transferred over the radio channel, when two different coding approaches are adopted: namely, rate compatible punctured convolutional codes and code combining [ABSTRACT FROM PUBLISHER]

This paper proposes some novel techniques to accommodate users with different rate requirements in a wideband code-division multiple-access system employing orthogonal variable spreading factor codes. Two simple static code assignment strategies are first considered, and an improvement based on multicode assignment. Then the new idea of tree partitioning is introduced and used to devise a dynamic code reassignment algorithm. The behavior of these different techniques is experimentally investigated, in terms of call blocking probability and number of required reassignments. The tree partitioning method exhibits very good performances. [ABSTRACT FROM PUBLISHER]

This paper analyses the behavior of two hybrid time-code division multiple-access (T/CDMA) architectures on the up-link of a macrocellular mobile radio system. For the examined schemes two categories of users-voice and data-share the domain of available resources, made up of time slots and codewords, through two alternative assignment strategies. Both solutions attribute voice users one single resource pair, i.e., one time slot and a single code to employ on that time slot, but differ in the way data users requests are accommodated: they are either simultaneously granted several codes over the same time slot or are assigned a single code over several distinct time slots. Call admission control is performed by a channel assignment algorithm which dynamically attributes resources only if specified levels of transmission quality are met on the radio channels. The blocking and the outage probability of the two classes of users are determined and compared, showing that one of the proposed schemes exhibits better performance and allows to satisfyingly serve a significant percentage of data users [ABSTRACT FROM PUBLISHER]

Abstract-Alternative code assignment policies for the forward link of a multicarrier DS-CDMA system employing the recently proposed quasi-orthogonal sequences are put forth in this letter. It is demonstrated how different allocation strategies of quasi-orthogonal codes alter the interference level suffered by active units; it is also shown how to shape the rate of interference growth as a function of the number of active users within the reference cell, implementing some specific code allocation patterns. The performance achieved by various schemes is assessed in a frequency selective fading environment, in terms of average bit error probability. [ABSTRACT FROM PUBLISHER]

In this letter, an accurate analytic model to predict the send rate of the SQRT binomial congestion control protocol is derived, under the assumption that the protocol operates in an environment where the packet loss rate is relatively high. Based on this model, a study of its TCP-friendliness is performed, remarking the nonnegligible effects on fairness that different queue managements have. [ABSTRACT FROM PUBLISHER]

This letter determines the capacity of a TDD-TD/CDMA architecture which supports different classes of subscribers and adopts an interference-driven admission control policy. The blocking probabilities of the system users are evaluated under various traffic conditions for several uplink/downlink configurations of the time slots, demonstrating that the time division full duplex approach needs careful tuning in order to maximize system capacity [ABSTRACT FROM PUBLISHER]

This letter analyzes the behavior of two time-code division architectures serving voice and data applications on the uplink of a cellular radio system. Both solutions attribute speech users one code over a timeslot, whereas data users are granted several codes over the same timeslot or a single code over several time slots. Call admission control dynamically attributes resources if specified levels of transmission quality are met. The blocking probability of the two classes of users is determined, demonstrating that the multicode T/CDMA approach performs better than the multislot solution and than a pure CDMA system [ABSTRACT FROM PUBLISHER]