In this paper, we study the achievable rate region of Gaussian multiuser channels with the messages transmitted being from finite input alphabets and the outputs being {\em quantized at the receiver}. In particular, we focus on the achievable rate region of $i)$ Gaussian broadcast channel (GBC) and $ii)$ Gaussian multiple access channel (GMAC). First, we study the achievable rate region of two-user GBC when the messages to be transmitted to both the users take values from finite signal sets and the received signal is quantized at both the users. We refer to this channel as {\em quantized broadcast channel (QBC)}. We observe that the capacity region defined for a GBC does not carry over as such to QBC. We show that the optimal decoding scheme for GBC (i.e., high SNR user doing successive decoding and low SNR user decoding its message alone) is not optimal for QBC. We then propose an achievable rate region for QBC based on two different schemes. We present achievable rate region results for the case of uniform quantization at the receivers. Next, we investigate the achievable rate region of two-user GMAC with finite input alphabet and quantized receiver output. We refer to this channel as {\em quantized multiple access channel (QMAC)}. We derive expressions for the achievable rate region of a two-user QMAC. We show that, with finite input alphabet, the achievable rate region with the commonly used uniform receiver quantizer has a significant loss compared to the achievable rate region without receiver quantization. We propose a {\em non-uniform quantizer} which has a significantly larger rate region compared to what is achieved with a uniform quantizer in QMAC.
Achievable rate region for three user discrete broadcast channel based on coset codes
基于嵌套陪集码,我们提出了一个一般三用户离散无记忆广播信道的可达速率域。我们的特点是3至1离散广播信道,一类广播信道,其中最有名的编码技术\footnote{We henceforth refer to this as Marton's coding for three user discrete broadcast channel.},这是通过一个自然的概括,由马顿提出的一般两个用户离散广播信道,是严格次优的。特别是,我们确定了一种新的3比1离散广播信道,其中马顿的编码被证明是严格次优的\textit{analytically}。我们提出了可实现的速率区域为一般的3比1离散广播信道,嵌套陪集码的基础上,严格扩大马顿的速率区域为上述通道。我们推广到目前的可达速率区域一般三用户离散广播信道。结合马顿的编码和这里提出的,我们提出了最知名的编码技术,一般的三个用户的离散广播信道。
For the two-user multiple-input multiple-output (MIMO) broadcast channel with delayed channel state information at the transmitter (CSIT) and arbitrary antenna configurations, all the degrees-of-freedom (DoF) regions are obtained. However, for the three-user MIMO broadcast channel with delayed CSIT and arbitrary antenna configurations, the DoF region of order-2 messages is still unclear and only a partial achievable DoF region of order-1 messages is obtained, where the order-2 messages and order-1 messages are desired by two receivers and one receiver, respectively. In this paper, for the thre…
Reconfigurable intelligent surfaces (RISs) represent a new technology that can shape the radio wave propagation and thus offers a great variety of possible performance and implementation gains. Motivated by this, we investigate the achievable sum-rate optimization in a broadcast channel (BC) that is equipped with an RIS. We exploit the well-known duality between the Gaussian multiple-input multiple-output (MIMO) BC and multiple-access channel (MAC) to derive an alternating optimization (AO) algorithm which optimizes the users' covariance matrices and the RIS phase shifts in the dual MAC. The o…
In optical wireless communications, a broadcast channel (BC) employing intensity modulation and direct detection (IM/DD) is often modelled as a peak-constrained BC. A closed-form expression for its capacity region of the peak-constrained BC is not known. This paper presents an analytical capacity inner bound for the peak-constrained Gaussian BC achieved by a class of discrete input distribution, specifically, the evenly-spaced discrete uniform distribution (ESDU). In contrast to the continuous input distribution that provides the benchmark, ESDU is more promising in the application of peak-con…
This paper focuses on $ K $-receiver discrete-time memoryless broadcast channels (DM-BCs) with private messages, where the transmitter wishes to convey $K$ private messages to $K$ receivers respectively. A general inner bound on the capacity region is proposed based on an exhaustive message splitting and a $K$-level modified Marton's coding. The key idea is to split every message into $ \sum_{j=1}^K {K\choose j} $ submessages each corresponding to a set of users who are assigned to recover them, and then send these submessages through codewords that are jointly typical with each other. To guar…
Reconfigurable intelligent surfaces (RISs) represent a new technology that can shape the radio wave propagation and thus offers a great variety of possible performance and implementation gains. Motivated by this, we investigate the achievable sum-rate optimization in a broadcast channel (BC) in the presence of RISs. We solve this problem by exploiting the well-known duality between the Gaussian multiple-input multiple-output (MIMO) BC and the multiple-access channel (MAC), and we correspondingly derive three algorithms which optimize the users' covariance matrices and the RIS phase shifts in t…
Achievable Rate Region of the Zero-Forcing Precoder in a 2 X 2 MU-MISO Broadcast VLC Channel with Per-LED Peak Power Constraint and Dimming Control
在本文中,我们考虑2 × 2多用户多输入单输出(MU-MISO)广播可见光通信(VLC)信道的两个发光二极管(LED)在发送端和一个单一的光电二极管(PD)在两个用户的每一个。我们提出了在每LED峰值和平均功率约束下的该2 X 2 MU-MISO VLC信道中的迫零(ZF)预编码器的可实现速率区域,其中从每个LED发射的平均光功率对于恒定照明是固定的,但是是可控的(在VLC上的IEEE 802.15.7标准中称为调光控制)。我们分析了所提出的速率区域边界的特征,并表明它是帕累托最优的。进一步的分析表明,当固定的每LED平均光功率是允许的每LED峰值光功率的一半时,实现了最大速率区域。我们还提出了一种新颖的收发器架构,其中信道编码器和调光控制分离,这大大简化了收发器的复杂性。一个室内VLC信道与建议的收发器的案例研究表明,可实现的信息速率是敏感的LED和PD的位置。一个有趣的观察是,对于在5 m X 5 m X 3 m房间中的LED的给定放置,即使用户从其最佳放置有相当大的位移,可实现速率的降低也不显著。因此,该观察结果可用于定义房间内的“覆盖区”,其中,对两个用户的信息速率的降低在可接受的容限内。
Capacity Bounds for Broadcast Channels with Confidential Messages
在本文中,我们研究了离散无记忆广播信道的容量界与机密消息。两个私人消息以及一个公共消息被传输;公共消息将由两个接收者解码,而每个私人消息仅用于其预期的接收者。此外,每个私人信息都要对非预期的接收者保密,其中保密性是通过模棱两可来衡量的。我们提出了内部和外部边界的速率模糊区域的广播信道与机密消息。建议的内界推广Csiszár和Körner的速率模糊区域的广播信道与一个单一的机密消息,刘{ \em et al}的可达速率区域的广播信道与完美的保密性,马顿和Gel'fand和Pinsker的可达速率区域的一般广播信道。我们提出的外边界,连同内边界,有助于建立几类离散无记忆广播信道的速率模糊区域的机密消息,包括少噪声,确定性和半确定性的信道。此外,专门为一般的广播信道通过删除的机密性约束,我们提出的外边界减少到新的容量外边界的离散内存广播信道。
We study the problem of coding over a general discrete memoryless broadcast channel controlled by random parameters. The parameters are available at the transmitter in a non-causal manner and are subject to a state masking constraint on the receivers. We derive inner and outer bounds on the achievable region and show that for the special case of Gaussian broadcast channel with private messages, these bounds are tight.
A novel class of achievable rate regions is obtained for the K-receiver broadcast channel with two groupcast messages. The associated achievability schemes are parameterized by an expansion of the message set which then determines how random coding techniques are employed, which include generalized versions of {\em up-set} message-splitting, the generation of possibly multiple auxiliary codebooks for certain compositions of split messages using superposition coding, partial interference decoding at all receivers, and joint unique and non-unique decoding. New capacity results are established fo…
Network Oblivious Transfer via Noisy Broadcast Channels
Institute for Communications Technology, Technische Universität Braunschweig(不伦瑞克工业大学通信技术研究所);Technische Universität München(慕尼黑工业大学);Munich Quantum Valley (MQV)(慕尼黑量子谷);Munich Center for Quantum Science and Technology (MCQST)(慕尼黑量子科学与技术中心)
In this letter, we characterize the performance of broadcast approach with continuum of transmission layers in random wireless networks where the channel state information (CSI) is assumed to be known only at the receiver. By modeling the transmitter-receiver pairs using bipolar Poisson point process, we derive analytical expressions for the mean and variance of achievable transmission rate and the network transmission capacity under broadcast approach. Our analysis shows that the broadcast approach provides better mean transmission rate with lower variance compared to outage strategy.
Secret-sharing building blocks based on quantum broadcast communication are studied. The confidential capacity region of the pure-loss bosonic broadcast channel is determined, both with and without key assistance, and an achievable region is established for the lossy bosonic broadcast channel. If the main receiver has a transmissivity of η<1/2, then confidentiality solely relies on the key-assisted encryption of the one-time pad. We also address conference key agreement for the distillation of two keys, a public key and a secret key. A regularized formula is derived for the key-agreement capac…
This work considers a layered coding approach for efficient transmission of data over a wireless block fading channel without transmitter channel state information (CSI), which is connected to a limited capacity reliable link, known as the bottleneck channel. Two main approaches are considered, the first is an oblivious approach, where the sampled noisy observations are compressed and transmitted over the bottleneck channel without having any knowledge of the original information codebook. The second approach is a non-oblivious decode-forward (DF) relay where the sampled noisy data is decoded,…
In this paper, we consider a general K-user Gaussian multiple-input multiple-output (MIMO) broadcast channel (BC). We assume that the channel state is deterministic and known to all the nodes. While the private-message capacity region is well known to be achievable with dirty paper coding (DPC), we are interested in the simpler linearly precoded transmission schemes. In particular, we focus on linear precoding schemes combined with rate-splitting (RS). First, we derive an achievable rate region with minimum mean square error (MMSE) precoding at the transmitter and joint decoding of the sub-mes…
This paper considers the single antenna, static Gaussian broadcast channel in the finite blocklength regime. Second order achievable and converse rate regions are presented. Both a global reliability requirement and per-user reliability requirements are considered. The two-user case is analyzed in detail, and generalizations to the $K$-user case are also discussed. The largest second order achievable region presented here requires both superposition and rate splitting in the code construction, as opposed to the (infinite blocklength, first order) capacity region which does not require rate spl…