DTSC - GTSA - Capítulos de Monografías
http://hdl.handle.net/10016/26218
2021-05-06T21:20:58ZA High-SNR Normal Approximation for MIMO Rayleigh Block-Fading Channels
http://hdl.handle.net/10016/30906
A High-SNR Normal Approximation for MIMO Rayleigh Block-Fading Channels
Qi, Chao; Koch, Tobias Mirco
This paper concerns the maximum coding rate at which a code of given blocklength can be transmitted with a given block-error probability over a non-coherent Rayleigh block-fading channel with multiple transmit and receive antennas (MIMO). In particular, a high-SNR normal approximation of the maximum coding rate is presented, which is proved to become accurate as the signal-to-noise ratio (SNR) and the number of coherence intervals L tend to infinity.
Proceeding of: 2020 IEEE International Symposium on Information Theory (ISIT), Los Angeles, CA, USA, 21-26 June 2020
2020-08-24T00:00:00ZBursty Wireless Networks of Bounded Capacity
http://hdl.handle.net/10016/30903
Bursty Wireless Networks of Bounded Capacity
Villacrés Estrada, Grace Silvana; Koch, Tobias Mirco; Vázquez Vilar, Gonzalo
The channel capacity of wireless networks Is often studied under the assumption that the communicating nodes have perfect channel-state information and that interference is always present. In this paper, we study the channel capacity of a wireless network without these assumptions, i.e., a bursty noncoherent wireless network where the users are grouped in cells and the base-station features several receive antennas. We demonstrate that the channel capacity is bounded in the signal-to-noise ratio (SNR) when the number of receive antennas is finite and the probability of presence of interference is strictly positive.
Proceeding of: 2020 IEEE International Symposium on Information Theory (ISIT), Los Angeles, CA, USA, 21-26 June 2020
2020-08-24T00:00:00ZCapacity per Unit-Energy of Gaussian Random Many-Access Channels
http://hdl.handle.net/10016/30902
Capacity per Unit-Energy of Gaussian Random Many-Access Channels
Ravikumaran Nair, Jithin; Koch, Tobias Mirco
We consider a Gaussian multiple-access channel with random user activity where the total number of userslₙ and the average number of active users kₙ may be unbounded. For this channel, we characterize the maximum number of bits that can be transmitted reliably per unit-energy in terms of lₙ and kₙ . We show that if kₙ log lₙ is sublinear in n, then each user can achieve the single-user capacity per unit-energy. Conversely, if kₙ log lₙ is superlinear in n, then the capacity per unit-energy is zero. We further demonstrate that orthogonal-access schemes, which are optimal when all users are active with probability one, can be strictly suboptimal.
Proceeding of: 2020 IEEE International Symposium on Information Theory (ISIT), Los Angeles, CA, USA, 21-26 June 2020
2020-08-24T00:00:00ZFinite-Blocklength Approximations for Noncoherent Rayleigh Block-Fading Channels
http://hdl.handle.net/10016/30733
Finite-Blocklength Approximations for Noncoherent Rayleigh Block-Fading Channels
Lancho Serrano, Alejandro; Östman, Johan; Koch, Tobias Mirco; Vázquez Vilar, Gonzalo
Several emerging wireless communication services and applications have stringent latency requirements, necessitating the transmission of short packets. To obtain performance benchmarks for short-packet wireless communications, it is crucial to study the maximum coding rate as a function of the blocklength, commonly called finite-blocklength analysis. A finiteblocklength analysis can be performed via nonasymptotic bounds or via refined asymptotic approximations. This paper reviews finite-blocklength approximations for the noncoherent Rayleigh block-fading channel. These approximations have negligible computational cost compared to the nonasymptotic bounds and are shown to be accurate for error probabilities as small as 10-8 [super index] and SNRs down to 0 dB.
Proceeding of: 53rd Asilomar Conference on Signals, Systems, and Computers (ACSSC 2019), 3-6 Nov. 2019, Pacific Grove, CA, USA
2020-03-30T00:00:00Z