Lossless Source Coding in the Point-to-Point, Multiple Access, and Random Access Scenarios

This paper newly proposes a frequency domain backoff scheme dedicated to continuous beamforming space division multiple access (CB-SDMA) on massive antenna systems for wireless entrance (MAS-WE). The entrance base station (EBS) has individual base band signal processing units for respective relay stations (RSs) to be accommodated. EBS then continuously applies beamforming weight to transmission/reception signals. CB-SDMA yields virtual point-to-point backhaul link where radio resource control messages and complicated multiuser scheduling are not required. This simplified structure allows RSs to work in a distributed manner. However, one issue remains to be resolved; overloaded multiple access resulting in collision due to its random access nature. The frequency domain backoff mechanism is introduced instead of the time domain one. It can flexibly avoid co-channel interference caused by excessive spatial multiplexing. Computer simulation verifies its superiority in terms of system throughput and packet delay.

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Random Access Versus Multiple Access

Multiple Access Techniques for 5G Wireless Networks and Beyond ◽

10.1007/978-3-319-92090-0_17 ◽

2018 ◽

pp. 535-584

Author(s):

Riccardo De Gaudenzi ◽

Oscar del Río Herrero ◽

Stefano Cioni ◽

Alberto Mengali

Keyword(s):

Multiple Access ◽

Random Access

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CSNOMA: Carrier Sense Non-Orthogonal Multiple Access

Sensors ◽

10.3390/s20185024 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5024

Author(s):

Dong Min Kim ◽

Seong-Lyun Kim

Keyword(s):

Interference Cancellation ◽

Multiple Access ◽

Random Access ◽

Cross Layer Design ◽

Carrier Sense Multiple Access ◽

Mac Layers ◽

802.11 Dcf ◽

Carrier Sense ◽

Access Scheme ◽

Multiple Access Protocol

In this paper, we investigate the possibility of the cross-layer design of a distributed random access scheme with considering physical (PHY) and multiple access control (MAC) layers, which utilizes the interference cancellation technique. In this regard, we propose a new multiple access protocol, named carrier sense non-orthogonal multiple access (CSNOMA). We consider the spatially randomly distributed interferers to realistically capture the effect of interference. The proposed protocol shows better area spectral efficiency than carrier sense multiple access (CSMA), as the node density increases. We also present a practical signaling design compatible with IEEE 802.11 DCF mode.

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Stability and Delay of NDMA-MPR Protocol in Rice-Correlated Channels with Co-Channel Interference

Technologies ◽

10.3390/technologies7010022 ◽

2019 ◽

Vol 7 (1) ◽

pp. 22

Author(s):

Ramiro Sámano-Robles

Keyword(s):

Real Time ◽

Multiple Access ◽

Random Access ◽

Low Latency ◽

Multiple Antenna ◽

Average Delay ◽

Correlated Channels ◽

Binary Feedback ◽

Channel Interference ◽

Extended Analysis

This paper investigates backlog retransmission strategies for a class of random access protocols with retransmission diversity (i.e., network diversity multiple access or NDMA) combined with multiple-antenna-based multi-packet reception (MPR). This paper proposes NDMA-MPR as a candidate for 5G contention-based and ultra-low latency multiple access. This proposal is based on the following known features of NDMA-MPR: (1) near collision-free performance, (2) very low latency values, and (3) reduced feedback complexity (binary feedback). These features match the machine-type traffic, real-time, and dense object connectivity requirements in 5G. This work is an extension of previous works using a multiple antenna receiver with correlated Rice channels and co-channel interference modelled as a Rayleigh fading variable. Two backlog retransmission strategies are implemented: persistent and randomized. Boundaries and extended analysis of the system are here obtained for different network and channel conditions. Average delay is evaluated using the M/G/1 queue model with statistically independent vacations. The results suggest that NDMA-MPR can achieve very low values of latency that can guarantee real- or near-real-time performance for multiple access in 5G, even in scenarios with high correlation and moderate co-channel interference.

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