Matlab Based Design For Resource Allocation Platform

These carriers are called subcarriers and usually there is one more modulation to translate all

In the recent years, wireless technologies have taken a new dimension in the ways society lives. Wireless broadband is available to everyone. Whether the users are at home, driving the car, sitting in the park, and it would even work while people are a pleasure boat ride in the middle of a lake. And because of this, the need to have information at any time and be connected in all places, all the time has been satisfied.

The market for wireless communications has experienced incredible growth over recent years and wireless LANs have rapidly become a very

It’s very important to determine the device and application requirements based on bandwidth, protocols and frequency. In wireless network, bandwidth, protocols and sometime environmental conditions affect the speed of the channel so we need to calculate the aggregate throughputs before designing the network. Today, users carry Wi-Fi devices such as notebooks, laptops, tablets and Smartphone’s so total throughput must be calculated by estimating number of connections rather than the number of the seats. Some common wireless networking standards such as 802.11a/b/g/n invented in the IEEE association must be supported by wireless network. For better performance and for faster devices (802.11n devices), dual-ratio access points should be deployed. Table1 [3] illustrate the different IEEE standards and throughput.

These sub-carriers are orthogonal to each other. It is very much popular scheme used in digital television, audio broadcasting and 4G communications. OFDM has the ability to deal with severe channel fading conditions without complex equalization filters. Due to the longer symbol period and the CP extension, OFDM is more robust against the effect of timing offset and delay spread in multipath fading channels. OFDM also gain higher spectral efficiency due to the overlapping of the subcarrier spectrum which are orthogonal to each other. The major drawback of OFDM is high

But then also there are some disadvantages related to OFDM-CDMA systems. To differentiate among different users OFDM-CDMA uses different orthogonal codes and due to this orthogonality distortion occurs among users in frequency selective channel (especially in uplink transmission), which may cause problem of MAI. For MAI problem, MUD is a promising technique which is very complex in practical application. The detectors for OFDM-IDMA system like the linear MMSE detector and other de-correlator have the quadratic complexity with the number of users say K [22]. This quadratic complexity occurs to resolving the correlation operations involved in spreading sequences. The computational prohibitive occur for practical implementation if value of K is large.

Continual advancement in technology has led to the extension of wireless accessibility due to Wireless Fidelity (Wi-Fi), an important phenomenon that has been impacting the world over the past decade (Kioskea, 2015). The name Wi- Fi was first coined by Wi-Fi Alliance and it refers to wireless Ethernet 802.11 which defines standards for wireless local area networks (WLANs). But since 802.11 was considered too slow for some applications it was surpassed by extensions 802.11a and 802.11b, and later by 802.11g. Traditionally, this radio technology that uses frequency to transmit data through air was initially originated during late 1980s and was evolved with the fundamental objective of making data communication wireless. But today Wi-Fi has become a necessity for both consumer and enterprise since it does not only represent a means of staying connected at home or at the internet and checking emails and surfing the web, it is also consumed by the users for content purposes such as streaming music and high

obliges in any event twice the same number of clients per MHz than GSM. To add

Despite its many advantages, Li-Fi like any other technology also comes with a number of limitations and disadvantages [11]. These are enumerated

The problem becomes intense when there are many OBSS using the same channel. The wide range WLAN usage has caused “tragedy of commons” problem especially at public places. OBSS cause problems such as low efficiency, higher congestion and low data rate. OBSS is a problem for 802.11 when it is intended to use for applications which require QoS. EDCA does not solve this problem as it does not require other BSSs to coordinate. Admission control only solves bandwidth allocation problem within a single network and does not address OBSS [2].

The increase in the transmission speed in the IEEE 802.11n standard is achieved, firstly, due to the doubling of the channel width from 20 to 40 MHz, and secondly, due to the implementation of MIMO technology. MIMO (Multiple Input Multiple Output) technology involves the use of multiple transmit and receive antennas. (Mitchell, 2017)

These techniques allow a large number of users to access information through the same channel in wireless communication systems, also regarded as air-interface as mentioned previously. Thus, also making effective use of allocated bandwidth. The following three techniques come under this category:

Generally speaking, synchronization is divided into timing and frequency synchronization. In practice, the oscillator does not produce a carrier at exactly one frequency, and the carrier frequency is modulated by random phase jitter [2]. The phase noise introduced results in a mismatch of frequencies between the local oscillators at the transmitter and the receiver. In addition, Doppler effects in fading channel also causes frequency offsets at the receiving carrier. As a result, the numbers of subcarriers cycles within the FFT period are not integers anymore, and the orthogonality property between subcarriers is not kept, causing ICI for an OFDM system. In contrast, in a

This report explores the topic on frequency allocation but more specifically within a context of mobile networks and the mathematics involved. We will focus more towards the issue of frequency allocation/assignment as well as touching base on the historical context of the issue and it 's influence of our approach towards the problem today.

The concentration of small cells in a network increases; measures need to be taken in order to ensure that the QoS is not degraded for the macrocell users as well as its nearest small cells. Interference managing in Heterogeneous Network in critical position .This is characteristically attained completed bright resource allocation schemes for small cells. In Heterogeneous Network, the mobile network is constructed with layers of small and large cells. This architecture is faced with the task of supply allocation (power, channel, time) for small cells in order to guarantee reliable and high quality service to both primary (macrocell) users as well as secondary (femtocell) users. In mobile network all users can be considered as nomadic, in the form of microcells, hot-spots, circulated antennas and relays becomes predictable. Therefore, for the deployment of the LTE systems the FAPs get a critical inspiring subject, mostly relating to the technical and business influences that it could signify and the method they could be combined efficiently into the LTE building.