Performance analysis of vehicular device-to-device underlay communication

Increasing demand for vehicular mobile data services is leading to the need for alternative communication methods aside from cellular networks.
This paper focuses on vehicular device-to-device (V-D2D) communications that utilize cellular uplink resources, analyzing performance through a model of an urban grid layout with varying vehicle density.
A joint power control and mode selection scheme is proposed for V-D2D communications, employing channel inversion to control transmit power and select transmission modes based on channel quality.
Key performance metrics such as signal-to-interference-plus-noise outage probability and link/network throughput are analyzed.

Future vehicles aim to be faster, safer, greener, and more entertaining, relying on vehicular ad hoc networks (VANETs).
VANETs enable vehicles to communicate with each other and with external networks, facilitating applications including collision warnings, traffic management, and mobile data services.
The growth of connected vehicles creates a critical need for reliable and high-capacity data communications, often cumbersome for current cellular methods.

Cellular technologies like LTE provide reliable Internet access but face challenges due to increasing mobile data traffic, leading to congestion and degraded service for all users.
Dedicated Short-Range Communication (DSRC) can support various applications but is also limited by bandwidth, especially in dense urban settings.

V-D2D communication allows direct communication between proximate users, enhancing spectrum efficiency and reducing latency by avoiding base station routing.
Control over D2D communications by cellular networks can lead to improved performance through interference management and lower costs compared to traditional cellular communications.
The potential for offloading cellular transmissions to V-D2D connections can alleviate network congestion and optimize resource allocation.

There is a lack of systematic theoretical studies on the performance of V-D2D communication in urban scenarios.
Unique vehicle mobility patterns and the constraints of urban road topologies need to be addressed for accurate performance modeling.

The urban road layout is modeled as a grid pattern, considering vehicle distribution and mobility characteristics.
A channel inversion power control mechanism is proposed, along with a bias factor-based mode selection strategy that influences the choice between D2D and cellular modes for data transmission.
Performance metrics such as SINR outage probability and throughput are derived and validated through simulations.
Notably, the relationship between transmission power, bias factors, and interference patterns is explored to understand their impact on network performance.

Transmission Mode Selection: A biased mode selection strategy influences whether VUs choose D2D or cellular modes based on channel quality.
Impact of Bias Factor: The bias factor significantly affects D2D mode selection, with higher values increasing the likelihood of choosing D2D mode, potentially leading to more interference but enhanced spatial frequency reuse.
Performance Insights: Both SINR outage probability and throughput performance depend on design parameters like channel inversion threshold and bias factor, which influence overall network capacity and reliability.

The analytical framework developed provides valuable insights for cellular network operators aiming to utilize V-D2D communications effectively.
Future research will expand the analysis of V-D2D performance across different environments, such as highways, and incorporate considerations of user preferences and cost efficiency.

Cellular networks, device-to-device communication, heterogeneous networks, mobile data offloading, vehicular communication.