Multiple Packet Reception Capability Research Articles

Performance Analysis for Asynchronous Requests in Wireless Networks with Multiple Packet Reception Capability

An important key technology used in the new standard IEEE 802.11ax is a multiple-user multiple-input multiple-output (MU-MIMO) antenna technology. With MU-MIMO technology, a wireless access point (AP) can increase network throughput by simultaneously multiple packet reception (MPR) from wireless users. Using MPR capability, the new medium access control (MAC) protocol is proposed to allow wireless users transmitting packets at the same time and even when there is an ongoing transmission in the network. The new mechanism for transmission process allows users to transmit packets on two conditions; the time during first ongoing RTS frame transmission and the total ongoing users less than maximum MPR capability. In addition, the format of frame control is modified to identify the multiple packet transmission. For performance evaluation, the mathematical model is derived to calculate throughput and the probability of idle, success transmission, and collision of the network. Moreover, the results are validated by MATLAB program simulation. The results show that throughput obtained by the proposed protocol is about 40% higher than that obtained by the carrier sense multiple access with collision avoidance (CSMA/CA) protocol when the maximum MPR capability is two and the contention window size is sixty-four. Moreover, the probability of success transmission increases when the number of transmissions equals to the maximum MPR capability. Finally, to obtain high throughput, the contention window size should be optimized with the number of users and the maximum MPR capability.

Generalized $p$ -Persistent CSMA for Asynchronous Multiple-Packet Reception

This paper considers a multiple-access system with multiple-packet reception (MPR) capability $\gamma $ , i.e., a packet can be successfully received as long as it overlaps with $\gamma -1$ or fewer other packets at any instant during its lifetime. To efficiently utilize the MPR capability, this paper generalizes $p$ -persistent carrier-sense multiple access (CSMA) to consider that a user with carrier sensing capability $c$ adopts the transmission probability $p_{n}$ if this user has sensed $n$ ongoing transmissions for $n=0,1,\ldots ,c-1$ . This paper aims to model the characteristics of such CSMA and to design transmission probabilities for achieving maximum saturation throughput. To this end, we first formulate such CSMA as a parameterized Markov decision process (MDP) and use the long-run average performance to evaluate the saturation throughput. Second, by observing that the exact values of optimal transmission probabilities are in general infeasible to find, we modify this MDP to establish an upper bound on the maximum throughput, and modify this MDP again to propose a heuristic design with near-optimal performance. Simulations with respect to a wide range of configurations are provided to validate our study. The throughput performance under more general models and the robustness of our design are also investigated.

Random Pattern Multiplexing for Random Access in IoT-Oriented Satellite Networks

In this paper, random pattern multiplexing (RPM) for random access (RA) is proposed to improve the throughput in Internet of Things-oriented satellite networks. The pattern is defined as the mapping scheme of packet onto a resource block (RB) that consists of multiple resource elements (REs). The patterns are randomly selected by active satellite machine-type-communication terminals (SMTs) from a set of available patterns, and are employed to differentiate signals of different SMTs sharing a RB. Message passing detection algorithm is employed to decode multiple superimposed packets, which enables multiple packet reception capability in the RA scheme. The proposed RPM can be combined with contention resolution diversity slotted ALOHA (CRDSA), which generates RPM–CRDSA protocol. In this protocol, the interference cancellation technique can be carried out across RBs to remove the received signals that are already decoded, which further improves the throughput. The performance of RPM–CRDSA is evaluated via mathematical analysis and computer simulation. The probability of preamble collision and an upper bound of throughput are derived, respectively. Simulation results show that the peak normalized throughput of RPM–CRDSA with $N = 4$ REs can reach 2.03 b/symbol, which largely outperforms traditional protocols.

An Effective Multiuser Detection Scheme for MPR Random Access Networks

Packet collision is a well-known severe impairment in ALOHA-based networks and, more generally, in any random access network. As a consequence, several methodologies have been considered with the aim of lowering the resulting performance degradation. A novel multiuser detection scheme exploiting channel diversity to separate collided signals is proposed here to enable multiple packet reception capability in random access schemes. The performance of this approach is analytically derived and optimized in terms of network throughput, and compared with that of different alternatives. The overall performance in terms of throughput shows the effectiveness of the proposed scheme in different operating conditions.

Throughput Improvement of 802.11 Networks Via Randomization of Transmission Power Levels

Successive interference cancelation can resolve collisions involving multiple packets and, hence, improve the throughput of an 802.11 network. This technique, however, requires packets to be sent with different power levels. In this paper, we first develop a detailed analytical model to determine the throughput of 802.11 networks with this multiple-packet reception capability. We then study the problem of determining the optimal probability distribution associating with these power levels when the network is operated in infrastructure and ad hoc modes, respectively. In the infrastructure mode, the problem is formulated as an optimization problem with a solution to be broadcast to all the nodes by the access point. In the ad hoc mode, the same problem is formulated as a mixed-strategy game, where individual nodes strategically choose the probability distribution of the transmitting power levels to maximize its own throughput. We show that the Nash equilibrium of this game is Pareto optimal and fair. Furthermore, the resulting throughput of the distributed approach is close to the optimal performance of the infrastructure mode.

Topology-Transparent Scheduling in Mobile Ad Hoc Networks With Multiple Packet Reception Capability

Recent advances in the physical layer have enabled wireless devices to have multiple packet reception (MPR) capability, which is the capability of decoding more than one packet, simultaneously, when concurrent transmissions occur. In this paper, we focus on the interaction between the MPR physical layer and the medium access control (MAC) layer. Some random access MAC protocols have been proposed to improve the network performance by exploiting the powerful MPR capability. However, there are very few investigations on the schedule-based MAC protocols. We propose a novel m-MPR-l-code topology-transparent scheduling ((m, l)-TTS) algorithm for mobile ad hoc networks with MPR, where m indicates the maximum number of concurrent transmissions being decoded, and l is the number of codes assigned to each user. Our algorithm can take full advantage of the MPR capability to improve the network performance. The minimum guaranteed throughput and average throughput of our algorithm are studied analytically. The improvement of our (m, l)-TTS algorithm over the conventional topology-transparent scheduling algorithms with the collision-based reception model is linear with m. The simulation results show that our proposed algorithm performs better than slotted ALOHA as well.

Power levels and packet lengths in random multiple access with multiple-packet reception capability

This paper extends our earlier results. We assume that the receiver has the capability of capturing multiple packets so long as the signal-to-interference-plus-noise ratio (SINR) of each packet is above a designed threshold T throughout its transmission period. We prove that, compared with a multiple-power-level system, the single-power-level system in which all nodes transmit at the maximum allowable power level achieves optimal throughput, under a condition that T exceeds the value 3.33. Given a minimum throughput requirement, under the same condition on T, the single-power-level system also achieves the maximum average packet capture probability as well as the optimum energy usage efficiency. If the multiple-power-level systems are constrained such that higher power levels always have shorter packet lengths, then the above results hold for T greater than 2.

Multiple packet reception in wireless ad hoc networks using polynomial phase-modulating sequences

This paper proposes a blind interference cancellation algorithm that is able to provide multiple packet reception capability for asynchronous random access wireless mobile ad hoc networks. The algorithm exploits the fact that the baseband signal exhibits cyclostationarity properties, which are induced at the transmitters by means of modulating the symbols with polynomial phase sequences. This modulation does not expand the bandwidth and can be considered as a "color code" that can be used to distinguish one transmission from the others (i.e., packets from other users). The proposed technique does not require knowledge of the starting time of transmission of the desired signal and can also be applied to time-dispersive multipath channels. In addition, a practical way of assigning the color codes via the use of a common codebook known to all nodes is proposed, and the impact on local throughput of such a scheme is analyzed. Simulation results illustrate the excellent performance of the proposed approach.