Results 1 
9 of
9
Degrees of Freedom of RankDeficient MIMO Interference Channels
"... Abstract — We characterize the degrees of freedom (DoF) of multipleinput and multipleoutput (MIMO) interference channels with rankdeficient channel matrices. For the twouser rankdeficient MIMO interference channel, we provide a tight outer bound to show that the previously known achievable DoF ..."
Abstract

Cited by 5 (4 self)
 Add to MetaCart
Abstract — We characterize the degrees of freedom (DoF) of multipleinput and multipleoutput (MIMO) interference channels with rankdeficient channel matrices. For the twouser rankdeficient MIMO interference channel, we provide a tight outer bound to show that the previously known achievable DoF in the symmetric case is optimal and generalize the result to fully asymmetric settings. For the Kuser rankdeficient interference channel, we improve the previously known achievable DoF and provide a tight outer bound to establish optimality in symmetric settings. In particular, we show that for the Kuser rankdeficient interference channel, when all nodes have M antennas, all direct channels have rank D0, all cross channels are of rank D, and the channels are otherwise generic, the optimal DoF value per user is min(D0, M − (min(M, (K − 1)D)/2)). Notably for interference channels, the rankdeficiency of direct channels does not help and the rank deficiency of crosschannels does not hurt. The main technical challenge is to account for the spatial dependences introduced by rank deficiencies in the interference alignment schemes that typically rely on the independence of channel coefficients. Index Terms — Channel capacity, degrees of freedom, interference channel, multipleinput multipleoutput (MIMO), rank deficient channels, interference alignment I.
On the Capacity of the Finite Field Counterparts of Wireless Interference Networks
, 2013
"... This work explores how degrees of freedom (DoF) results from wireless networks can be translated into capacity or linear capacity results for their finite field counterparts that arise in network coding applications. The main insight is that scalar (SISO) finite field channels over Fpn are analogous ..."
Abstract

Cited by 5 (3 self)
 Add to MetaCart
This work explores how degrees of freedom (DoF) results from wireless networks can be translated into capacity or linear capacity results for their finite field counterparts that arise in network coding applications. The main insight is that scalar (SISO) finite field channels over Fpn are analogous to n × n vector (MIMO) channels in the wireless setting, but with an important distinction – there is additional structure due to finite field arithmetic which enforces commutativity of matrix multiplication and limits the channel diversity to n, making these channels similar to diagonal channels in the wireless setting. Within the limits imposed by the channel structure, the DoF optimal precoding solutions for wireless networks can be translated into capacity or linear capacity optimal solutions for their finite field counterparts. This is shown through the study of capacity of the 2user X channel and linear capacity of the 3user interference channel. Besides bringing the insights from wireless networks into network coding applications, the study of finite field networks over Fpn also touches upon important open problems in wireless networks (finite SNR, finite diversity scenarios) through interesting parallels between p and SNR, and n and diversity.
Fundamental limits and insights: from wireless communication to DNA sequencing
, 2013
"... ..."
(Show Context)
DOI: 10.1109/SPAWC.2013.6612061 Degrees of Freedom of Certain Interference Alignment Schemes with Distributed CSI
, 2013
"... Abstract—In this work, we consider the use of interference alignment (IA) in a MIMO interference channel (IC) under the assumption that each transmitter (TX) has access to channel state information (CSI) that generally differs from that available to other TXs. This setting is referred to as distribu ..."
Abstract
 Add to MetaCart
(Show Context)
Abstract—In this work, we consider the use of interference alignment (IA) in a MIMO interference channel (IC) under the assumption that each transmitter (TX) has access to channel state information (CSI) that generally differs from that available to other TXs. This setting is referred to as distributed CSIT. In a setting where CSI accuracy is controlled by a set of power exponents, we show that in the static 3user MIMO square IC, the number of degreesoffreedom (DoF) that can be achieved with distributed CSIT is at least equal to the DoF achieved with the worst accuracy taken across the TXs and across the interfering links. We conjecture further that this represents exactly the DoF achieved. This result is in strong contrast with the centralized CSIT configuration usually studied (where all the TXs share the same, possibly imperfect, channel estimate) for which it was shown that the DoF achieved at receiver (RX) i is solely limited by the quality of its own feedback. This shows the critical impact of CSI discrepancies between the TXs, and highlights the price paid by distributed precoding. I.
COMMUNICATION STRATEGIES FOR THE MIMO INTERFERENCE CHANNEL
, 2011
"... Managing interference for wireless networks is crucial for meeting future demand for higher mobile data rates. Interference can be viewed through the interference channel (IC) in which pairs of transmitters and receivers interfere with each other, so an interesting way to manage interference is to d ..."
Abstract
 Add to MetaCart
Managing interference for wireless networks is crucial for meeting future demand for higher mobile data rates. Interference can be viewed through the interference channel (IC) in which pairs of transmitters and receivers interfere with each other, so an interesting way to manage interference is to develop communication strategies for the IC. We consider the problem of designing signals to transmit over the multiple input and multiple output (MIMO) interference channel by extending the Max SINR algorithm. The Max SINR algorithm starts with arbitrary beamformers and then designs optimal receivers to maximize the SINR at each receiver. The Max SINR algorithm then alternates the direction of communication and repeats this process. This algorithm is known to perform well, but there is no proof that it converges. We propose a modification to Max SINR using a power control step to make a metric similar to sum rate converge. With successive interference cancellation (SIC), then the new metric is exactly the sum rate. Finally, simulations show that the performance of the modified Max SINR
Spécialité ”Communication et Électronique“
, 2012
"... pour obtenir le grade de docteur délivré par ..."
(Show Context)
1Degrees of Freedom of Certain Interference Alignment Schemes with Distributed CSIT
"... In this work, we consider the use of interference alignment (IA) in a MIMO interference channel (IC) under the assumption that each transmitter (TX) has access to channel state information (CSI) that generally differs from that available to other TXs. This setting is referred to as distributed CSIT. ..."
Abstract
 Add to MetaCart
(Show Context)
In this work, we consider the use of interference alignment (IA) in a MIMO interference channel (IC) under the assumption that each transmitter (TX) has access to channel state information (CSI) that generally differs from that available to other TXs. This setting is referred to as distributed CSIT. In a setting where CSI accuracy is controlled by a set of power exponents, we show that in the static 3user MIMO square IC, the number of degreesoffreedom (DoF) that can be achieved with distributed CSIT is at least equal to the DoF achieved with the worst accuracy taken across the TXs and across the interfering links. We conjecture further that this represents exactly the DoF achieved. This result is in strong contrast with the centralized CSIT configuration usually studied (where all the TXs share the same, possibly imperfect, channel estimate) for which it was shown that the DoF achieved at receiver (RX) i is solely limited by the quality of its own feedback. This shows the critical impact of CSI discrepancies between the TXs, and highlights the price paid by distributed precoding.
Channel Diversity needed for Vector Interference Alignment Tradeoff between DoF and Diversity For 3user interference channel [2],
"... interference channel Each receiver wants to obtain a message from its corresponding transmitter, but the signal is superimposed by interferences from other transmitters [1] V. Cadambe and S. A. Jafar, “Interference alignment and degrees of freedom of the Kuser interference channel, ” IEEE ..."
Abstract
 Add to MetaCart
(Show Context)
interference channel Each receiver wants to obtain a message from its corresponding transmitter, but the signal is superimposed by interferences from other transmitters [1] V. Cadambe and S. A. Jafar, “Interference alignment and degrees of freedom of the Kuser interference channel, ” IEEE