Advantages And Disadvantages Of FDMA

The different MIMO formats - SISO, SIMO, MISO and MIMO require different numbers of antennas as well as having different levels of complexity. Also dependent upon the format, processing may be needed at one end of the link or the other - this can have an impact on any decisions made.

formula is the equation of an N-point inverse discrete Fourier transform (IDFT). If N is a power

In the U.S., the Patient Protection and Affordable Care Act, authorized the FDA to approve generic versions of biologic drugs and grant drug manufacturers 12 years of exclusive use before generics can be developed. The FDA law offers PharmaCARE a 180 day exclusivity period to generic drug manufacturers in specific cases. Only one generic manufacturer can produce the generic version of a drug during the exclusivity period. This exclusivity period is only used when a generic manufacturer argues that a patent is invalid or is not violated in the generic production of a drug, and the period acts as a reward for the generic manufacturer who is willing to risk liability in court and the cost of patent court litigation. There is often contention around

The applications include wireless local area networks, wireless personal area networks and wireless metropolitan networks. Currently, OFDMA is being investigated as one of the most promising radio transmission techniques for LTE of the 3rd Generation Partnership Project (3GPP), International Mobile Telecommunications-Advanced

In this paper we propose a resource allocation scheme for coordinated multipoint (CoMP). The transmit power is allocated to spatial layer. The transmit power is allocated to spatial layer under the total base station power constraint and the per base station power constraint

First of all it is necessary to understand the terminology used in this paper in particular: unlicensed bands, traffic offloading and resource sharing. Wireless spectrum consists of two parts: licensed spectrum, which consists of licensed bands and unlicensed spectrum, which consists of unlicensed bands. Both unlicensed and licensed bands are frequency bands, which are used to transmit and receive information. Unlike licensed spectrum, which is owned by companies, unlicensed spectrum is more of a free space, where users can

Spectrum is a limited and valuable resource. The escalating requirement for wireless communication and broadband services has augmented the attempts to improve the designs for wireless systems. These enhanced wireless systems offer substantial increase in data throughput and link range without the requirement of any additional bandwidth. This led to the development of MIMO Systems. In Multiple-Input Multiple-Output (MIMO) technology, multiple antennas are used at both the transmitter and receiver to improve the functioning of the wireless communication system. We accomplish this objective by exploiting the spatial domain of the transmission medium.

For first design challenge, interference can inflicted by either through average (long term) transmit-power constraints or instantaneous (short term) constraints [4]. The instantaneous constraints have been focused as the second design challenge, handling these constraints

Where fh and fL are upper and lower band limits, respectively. Relative bandwidth in excess of 100% are possible for some antenna types.

This is one of the reasons for the popularity of 60GHz MMW. Inter-system interference is another concern. The UWB band is overlaid over the 2.4 and 5GHZ unlicensed bands used for increasingly deployed WLANs, thus the mutual interferences would be getting worse and worse. In order to protect the existing wireless systems operating in different regions, regulatory bodies in these regions are working on their own requirements for UWB implementation. Worldwide harmonization around 60GHz is possible, but it almost impossible for a regional UWB radio to work in another region. Unlicensed use in Japan is permitted at the 3.4-4.8GHz and 7.25-10.25 GHz wireless spectra, the letter of which is reserved for indoor products only.

There is a significant gap between the concept of a wireless system and the realization of that working design. Bridging this gap typically involves teams of engineers with a variety of different skill sets (RF, SW, DSP, HDL, embedded Linux, etc.), and in many cases projects get de-railed early in the development stage because of difficulty in coordinating the efforts of these varied design entities.

Due to the spectacular growth of the wireless services and demands during the last years, the need of a modulation technique that could transmit high data rates at high bandwidth efficiency strongly imposed. The problem of the inter–symbol interference (ISI) introduced by the frequency selectivity of the channel became even more imperative once the desired transmission rates dramatically grew up. Using adaptive equalization techniques at the receiver in order to combat the ISI effects could be the solution, but there are practical difficulties in operating this equalization in real-time conditions at several Mb/s with compact, low-cost hardware.

Abstract- In this work, an integrated passive optical network and free space optical communication system based on no-carrier single sideband modulation is proposed. Optical orthogonal frequency multiplexing is employed with dense wavelength division multiplexing to support 16 channels over 300 km bidirectional single mode fiber to enhance spectral efficiency and reduce inter-symbol interference. Moreover, wavelength reuse is also realized to design cost effective optical network units. Results revealed that the proposed framework successfully accomplished the 300 km symmetrical distance and

In a single carrier system, single fade causes the whole data stream and undergo distortion i.e frequency selective fading. The Single carrier systems also suffer with heavy Inter Symbol Interference . In telecommunication Inter Symbol Interference was a form of distortion of signal in which one symbol interferes with the subsequent symbol. Thus it causes an unwanted phenomena as the previous symbols have similar effect as noise thus making communication less reliable . ISI occurs when the signal bandwidth is less than the coherence bandwidth or when the delay spread is greater than symbol duration. To combat the problem multicarrier techniques have been proposed for high data rate transmission. Multicarrier techniques divide the whole bandwidth into large number of narrow band orthogonal subcarriers [1, 2]. Thus the signal bandwidth becomes very less compared with coherence bandwidth ensuring no ISI in time domain and flat fading in frequency domain. Multicarrier systems such as Orthogonal Frequency Division Multiplexing (OFDM) and Multi Carrier Code Division Multiple Access (MC-CDMA) were considered to be the best technologies for 4G wireless communication [1, 2]. Fig. explains the spectrum of multicarrier and single carrier systems. In the single carrier system the information symbols are loaded into one of

This paper will discuss the design of an FM receiver. It will begin with a brief historical