European Journal of Applied Sciences 4 (5): 207-210, 2012 ISSN 2079-2077 © IDOSI Publications, 2012 DOI: 10.5829/idosi.ejas.2012.4.5.1105 Corresponding Author: Ehsan Nowroozi, Department of Electrical and Electronical Enginnering, Yazd Institute of Higher Education, Yazd, Iran 207 QAM and IQ Filtering Combination and Analyzing its Time Optimization in Sending - Receiving Systems Ehsan Nowroozi Department of Electrical and Electronical Enginnering, Yazd Institute of Higher Education, Yazd, Iran Abstract: This paper is mainly about QAM Signal Analyzing and its combination for optimizing IQ Filtering in sending- receiving systems such as modems,… . changing QAM systems to fuzzy mode has been changed analog- digital convergence in telecommunication systems, especially near to some time zone neighbors. We use ADC signal waves to analyzing QAM and IQ filters functions. Key words: QAM System IQ filtering Telecom signals Sending - receiving systems INTRODUCTION For example, most energy at frequencies below an In MPSK modulation difference is only in phase and signals with a low pass filter with bandwidth These are a pulse modulation pulse MASK difference is only in scope sampling rate for frequency Or later require. It should be but the difference in Fuzzy MQAM is pulse amplitude. noted that most telecommunications systems for voice It should be noted that M = 2 and the pulse signal so transmission speed for sampling frequency Using. they can be composed of two component sine cosine After this introduction, we describe each of the decomposition . it means in this case the signal is the one blocks used in a modem Explains. with the DSB modulation And another For this reason it is called QAM. Transmitter Section MQAM modulation as mentioned two hunting is Analog to Digital Converters: Analog to digital converter precisely the one with 90° phase difference other than (ADC signal with limited bandwidth) for digital there. As can be seen in the figure below, first two transmission and it takes practice and analog quantization components I and Q QAM in medullary tour is produced levels in each sample to a discrete quantization level will as follows: convert. MQAM modulation with band width Is sufficient for For example, an 8-bit analog to digital converters each detection is correlated with the two components is separated by a quantization level of 8-bit binary response calculated sine and cosine. at the output there. The following chart shows the type of Modem QAM: A data communication system to the public Digital communication between systems and often shall be performed and after some processing and analog communication systems employing traditional frequency conversion to data and sends this action to techniques in signal transduction is. In an analog radio reverse the receiver does. QAM system block diagram is signal was sent directly modulated and often simple shown in Fig. 1. multiplication is carried hunting. On the other side more In a digital communication system to the modem than the digital systems use modulation correlation that input signals from a source of a series of digital signal or can input data with good quality on the map hunting. an encoded channel. If that although the input signal to Despite the complexity of digital systems using digital the modem through an analog source is produced, prior techniques to link the cause of the digital signal can be exposure to the width of the sampling position Band B is processed with fewer errors to be delivered while the limited. According to a theorem the sampling frequency analog system due to the usual Gaussian noise control must be twice the bandwidth is. equipment are data loss. audio signal Concentrated and thus spoke the kind of operation in an ADC are: