Multiaccess Communication via a Broadcast Approach Adapted to the Multiuser Channel

Abstract

A broadcast strategy for multiple access communication over slowly fading channels is introduced, in which the channel state information is known to only the receiver. In this strategy, the transmitters split their information streams into multiple independent information streams, each adapted to a specific actual channel realization. The major distinction between the proposed strategy and the existing ones is that in the existing approaches, each transmitter adapts its transmission strategy only to the fading process of its direct channel to the receiver, hence directly adopting a single-user strategy previously designed for the single-user channels. However, the contribution of each user to a network-wide measure (e.g., sum-rate capacity) depends not only on the user's direct channel to the receiver, but also on the qualities of other channels.Driven by this premise, this paper proposes an alternative broadcast strategy in which the transmitters adapt their transmissions to the combined states resulting from all users' channels. This leads to generating a larger number of information streams by each transmitter and adopting a different decoding strategy by the receiver. An achievable rate region and an outer bound that capture the trade-off among the rates of different information layers are established, and it is shown that the achievable rate region subsumes the existing known capacity regions obtained based on adapting the broadcast approach to the single-user channels.

Broadcast Approach to Multiple Access With Local CSIT

“…Compared with a similar network with no CSIT investigated in [35], the major distinction is that the transmitters do not have a pre-fixed layering strategy, and each transmitter selects its layering approach dynamically, and based on the known instantaneous channel realization. Furthermore, the major distinction with a similar network with partial CSIT investigated in [36] is adapting the number of encoded layers proportionately to the strength of combined channel state.…”

“…Furthermore, we evaluate the average achievable rate region corresponding to the encoding and decoding approach proposed in [36] for the same channel settings to demostarate the gleaned gains. Finally, we illustrate the role of the partially available CSIT incorporated in the proposed approach by comparing the average rate regions with that of the approach proposed in [35] for the two-user MAC with no CSIT.…”

“…However, when the transmitters can only acquire the probability distribution of the fading channel state, without any instantaneous CSIT, the performance limits are not fully known. The broadcast approach is investigated for the two-user MAC with no CSIT in [32]- [35]. In [32], the broadcast approach proposed in [10] is applied to the Gaussian slowlyfading MAC channel and average rates for the individual users are analyzed.…”

“…In [33], the single-user broadcast approach is directly applied to the random access MAC with no CSIT, where the each user adpats its information layers to its own channel state. In [34] and [35], the same problem is studied, where in contrast to [33], the information layers of each transmitter are adapted to the combined state of the channels of all users, rendering a significantly larger achievable rate region. In this paper, we consider the two-user multiple access channel in which the transmitters have local CSI.…”

Design of Information Hiding Algorithm for Multi-Link Network Transmission Channel

“…If the preprocessing method does not change the size of secret information, the capacity of information hiding based on block channel coding is M max ; if the secret information is preprocessed by error-correcting coding (Wang et al 2015) and the error-correcting coding parameter is (n 2 , k 2 , t 2 ), the capacity of information hiding based on block channel coding for multi-link network transmission channel is: 5If the channel coding type is convolutional code (Galdino et al 2016), let the channel coding parameter as (n 1 , k 1 , t 1 ), where L denotes the length of coding constraint, and its value is generally L = (t 1 + 1)n 1 , indicating that the current code group is related to the previous code group (Kazemi & Tajer 2018), and t 1 denotes the number of correctable errors in the length of coding constraint, then the multi-link network transmission based on convolutional channel coding is carried out. The capacity of channel information hiding is:…”