Navid Yazdani

Multi-Frequency Time-Division multiple-access (MF-TDMA) resource packing

Multi-Frequency Time-Division (MF-TDMA) techniques allow a large community of users to share bandwidth efficiently. Resources can be allocated based on user demands and user capabilities. The resources allocated to each individual user must be packed together in the spectrum available to the system while maintaining certain constraints based on user capabilities. Increasing the resource packing efficiency directly increases system bandwidth efficiency. This paper describes the MF-TDMA packing problem, defines a packing algorithm, and evaluates the packing performance under various scenarios.

Dynamic Resource Allocation DAMA Alternatives Study for satellite communications systems

We consider the design of Demand Assigned Multiple Access (DAMA) algorithms that efficiently utilize limited RF uplink resources for packet switched military satellite communication networks. In previous work, we designed DAMA algorithms that optimized link layer efficiency and throughput while controlling delay and jitter. In this work we assess the ability of our DAMA algorithm to meet Service Level Agreements (SLA) between the Network Management System and the terminals. We evaluate the ability of four DAMA algorithms to provide terminals Committed Information Rates (CIR) under various system loading conditions. The designs have increasing levels of confidence in the accuracy of the predicted demand. Results show that although traffic demand cannot be predicted precisely, current demand provides insight into future demands and that this information can be used to more efficiently provide CIR guarantees to terminals.

Jitter-aware time-frequency Resource Allocation and packing algorithm

One of the main components of the next generation protected military satellite communication systems is Dynamic Bandwidth Resource Allocation (DBRA). A centralized DBRA algorithm on the satellite dynamically grants terminals time and frequency resources as their traffic demands and channel conditions change, leading to significant increase in the overall system throughput.

Receiver design and bit allocation for a multi-user distributed relay network performing vector quantization

Given the increasing importance of mobile data access, extending broadband wireless access has become a global grand challenge. Relaying has been introduced to enable wireless communication between users lacking a common link. Distributed relay networks (DRN) are a special case where the relay consists of many geographically distributed single-antenna nodes to achieve spatial diversity. In this paper we introduce a quantized DRN where the relay nodes perform vector quantization before broadcasting downlink signals to the users. We derive performance-efficient receivers for this system and investigate a strategy for bit allocation across quantizers of the relay nodes to enhance the performance.

A scalable architecture for emulating Dynamic Resource Allocation in wireless networks

With the increasing size and complexity of emerging military communication networks, low footprint emulation methods are required to evaluate protocols, algorithms and user performance. In this paper we describe a new emulation architecture that is scalable, modular, and responds to real-time changes in topology and link characteristics. We use this scalable emulation testbed to evaluate system performance in a simple Satcom network topology, and enhance it to emulate Dynamic Resource Allocation using distributed software architecture.