On the DoF Region of the K-user MISO Broadcast Channel with Hybrid CSIT

Mohanty, Kaniska; Varanasi, Mahesh K.

doi:10.48550/arxiv.1312.1309

Cited by 6 publications

(15 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rx 1 supplying instantaneous CSIT, while Rx 2 , Rx 3 supply delayed CSIT) the prior results suggest that LDoF sum ≤ 17 9 [17], [21], while by Theorem 1, LDoF sum is indeed equal to 9 5 . Similarly, for the case of P P D, the prior results [17], [21] imply that LDoF sum ≤ 7 3 , while by Theorem 1, LDoF sum = 9 4 Remark 2. Theorem 1 implies that the state-of-the-art achievable schemes presented in [18] for P P D and P DD are both optimal from the perspective of LDoF sum .…”

Section: -User Miso Broadcast Channel With Hybrid Csitmentioning

confidence: 83%

“…) can be proven similarly using symmetry. Moreover, the bound d1 3 + d2 2 + d 3 ≤ 1 follows directly from the existing state-of-the-art arguments used in [3], [17]. Henceforth, we focus on proving d1 2 + d2 4 + d 3 ≤ 1.…”

Section: A Proof Of Converse For 3-user Miso Broadcast Channel With H...mentioning

confidence: 96%

“…For instance, for P DD (i.e. Rx 1 supplying instantaneous CSIT, while Rx 2 , Rx 3 supply delayed CSIT) the prior results suggest that LDoF sum ≤ 17 9 [17], [21], while by Theorem 1, LDoF sum is indeed equal to 9 5 . Similarly, for the case of P P D, the prior results [17], [21] imply that LDoF sum ≤ 7 3 , while by Theorem 1, LDoF sum = 9 4 Remark 2.…”

Section: -User Miso Broadcast Channel With Hybrid Csitmentioning

confidence: 99%

See 2 more Smart Citations

MISO Broadcast Channel With Hybrid CSIT: Beyond Two Users

Lashgari

Tandon

Avestimehr

2016

IEEE Trans. Inform. Theory

View full text Add to dashboard Cite

We study the impact of heterogeneity of channel-state-information available at the transmitters (CSIT) on the capacity of broadcast channels with a multiple-antenna transmitter and k single-antenna receivers (MISO BC). In particular, we consider the k-user MISO BC, where the CSIT with respect to each receiver can be either instantaneous/perfect, delayed, or not available; and we study the impact of this heterogeneity of CSIT on the degreesof-freedom (DoF) of such network. We first focus on the 3-user MISO BC; and we completely characterize the DoF region for all possible heterogeneous CSIT configurations, assuming linear encoding strategies at the transmitters. The result shows that the state-of-the-art achievable schemes in the literature are indeed sum-DoF optimal, when restricted to linear encoding schemes. To prove the result, we develop a novel bound, called Interference Decomposition Bound, which provides a lower bound on the interference dimension at a receiver which supplies delayed CSIT based on the average dimension of constituents of that interference, thereby decomposing the interference into its individual components. Furthermore, we extend our outer bound on the DoF region to the general k-user MISO BC, and demonstrate that it leads to an approximate characterization of linear sum-DoF to within an additive gap of 0.5 for a broad range of CSIT configurations. Moreover, for the special case where only one receiver supplies delayed CSIT, we completely characterize the linear sum-DoF.This work has been presented in part in [1], [2].

show abstract

Section: -User Miso Broadcast Channel With Hybrid Csitmentioning

confidence: 83%

Section: A Proof Of Converse For 3-user Miso Broadcast Channel With H...mentioning

confidence: 96%

Section: -User Miso Broadcast Channel With Hybrid Csitmentioning

confidence: 99%

See 1 more Smart Citation

MISO Broadcast Channel With Hybrid CSIT: Beyond Two Users

Lashgari

Tandon

Avestimehr

2016

IEEE Trans. Inform. Theory

View full text Add to dashboard Cite

show abstract

“…In [9] the synergistic benefits of alternating CSIT over fixed CSIT was presented in a two user MISO BC with two transmit antennas. In [10] and [11], the MISO BC with hybrid CSIT was considered, however our definition of hybrid CSIT is quite different with that of the aforementioned papers in the sense that instead of having a fixed state (either P or D) for the CSIT of a particular user, the state is allowed to alternate among P, D and N as in [9].…”

Section: Introductionmentioning

confidence: 99%

DoF analysis of the K-user MISO broadcast channel with hybrid CSIT

Rassouli

Hao

Clerckx

2015

2015 IEEE International Conference on Communications (ICC)

View full text Add to dashboard Cite

We consider a K-user multiple-input single-output (MISO) broadcast channel (BC) where the channel state information (CSI) of user i(i = 1, 2, . . . , K) may be either instantaneously perfect (P), delayed (D) or not known (N) at the transmitter with probabilities λ i P , λ i D and λ i N , respectively. In this setting, according to the three possible CSIT for each user, knowledge of the joint CSIT of the K users could have at most 3 K states. Although the results by Tandon et al. show that for the symmetric two user MISO BC (i.e., λ i Q = λQ, ∀i ∈ {1, 2}, Q ∈ {P, D, N }), the Degrees of Freedom (DoF) region depends only on the marginal probabilities, we show that this interesting result does not hold in general when K ≥ 3. In other words, the DoF region is a function of all the joint probabilities. In this paper, given the marginal probabilities of CSIT, we derive an outer bound for the DoF region of the K-user MISO BC. Subsequently, we investigate the achievability of the outer bound in some scenarios. Finally, we show the dependence of the DoF region on the joint probabilities. 1

show abstract

“…We present novel schemes for these two configurations which exploit hybrid channel knowledge to achieve sum DoF values of 9/5 and 9/4 respectively. The paper that is most relevant to this work is [8], in which outer bounds for the (K, K) MISO BC are obtained for general hybrid CSIT configurations. In addition, a coding scheme for (3, 3) MISO BC with PDD configuration is given which achieves 5/3 DoF.…”

Section: Introductionmentioning

confidence: 99%

On the degrees-of-freedom of the 3-user MISO broadcast channel with hybrid CSIT

Amuru

Tandon

Shamai

2014

2014 IEEE International Symposium on Information Theory

View full text Add to dashboard Cite

Abstract-The 3-user multiple-input single-output (MISO) broadcast channel (BC) with hybrid channel state information at the transmitter (CSIT) is considered. In this framework, there is perfect and instantaneous CSIT from a subset of users and delayed CSIT from the remaining users. We present new results on the degrees of freedom (DoF) of the 3-user MISO BC with hybrid CSIT. In particular, for the case of 2 transmit antennas, we show that with perfect CSIT from one user and delayed CSIT from the remaining two users, the optimal DoF is 5/3. For the case of 3 transmit antennas and the same hybrid CSIT setting, it is shown that a higher DoF of 9/5 is achievable and this result improves upon the best known bound. Furthermore, with 3 transmit antennas, and the hybrid CSIT setting in which there is perfect CSIT from two users and delayed CSIT from the third one, a novel scheme is presented which achieves 9/4 DoF. Our results also reveal new insights on how to utilize hybrid channel knowledge for multi-user scenarios.

show abstract

On the DoF Region of the K-user MISO Broadcast Channel with Hybrid CSIT

Cited by 6 publications

References 12 publications

MISO Broadcast Channel With Hybrid CSIT: Beyond Two Users

MISO Broadcast Channel With Hybrid CSIT: Beyond Two Users

DoF analysis of the K-user MISO broadcast channel with hybrid CSIT

On the degrees-of-freedom of the 3-user MISO broadcast channel with hybrid CSIT

Contact Info

Product

Resources

About