# Ppt on unipolar nrz format

##### Data and Computer Communications Ninth Edition by William Stallings Chapter 5 – Signal Encoding Techniques Data and Computer Communications, Ninth Edition.

binary data encoded into signal elements binary data encoded into signal elements Terminology  unipolar – all signal elements have the same sign  polar – one logic state / to noise ratio data rate bandwidth encoding scheme Digital Signal Encoding Formats Encoding Schemes signal spectrum good signal design should concentrate the transmitted/ bits that force transitions scramble data scramble data  not as efficient as NRZ each signal element only represents one bit each signal element only represents one/

##### Dwayne Whitten, D.B.A Mays Business School Texas A&M University

with a clear beginning and ending Computer networks send digital data using digital transmissions Data converted between analog and digital formats Modem (modulator/demodulator): used when digital data is sent as an analog transmission Codec (coder/decoder): used when / voltage levels will correspond to the bit values of 0 or 1 Examples: Bipolar RTZ (Return To Zero), NRZ (Non Return to Zero) Manchester Unipolar Data rate: describes how often the sender can transmit data 64 Kbps  once every 1/64000 of a/

##### Fundamentals of Data and Signals

pulse is called digital signal Question: How could we detect signal and represent them in digital format? (to p28) Representation of digital signals 3 most common forms of digital signals: 1. Unipolar “1” bit is represented by positive voltage and “0” bit by no voltage 2. /change at the beginning of a 1 and no voltage change at the beginning of a 0 Fundamental difference exists between NRZ-L and NRZI With NRZ-L, the receiver has to check the voltage level for each bit to determine whether the bit is a 0 or/

##### Copyright 2011 John Wiley & Sons, Inc3 - 1 Business Data Communications and Networking 11th Edition Jerry Fitzgerald and Alan Dennis John Wiley & Sons,

a clear beginning and ending –Computer networks send digital data using digital transmissions Data converted between analog and digital formats –Modem (modulator/demodulator): used when digital data is sent as an analog transmission –Codec (coder/decoder): used/circuit Signaling (encoding) –Defines how the voltage levels will correspond to the bit values of 0 or 1 –Examples: Unipolar, Bipolar RTZ, NRZ, Manchester –Data rate: describes how often the sender can transmit data 64 Kbps  once every 1/64000 of /

##### Sami Al-Wakeel 1 Data Transmission and Computer Networks Data Encoding.

Signals (Continued): Sami Al-Wakeel 7 Data Encoding 1. Digital Data, Digital Signals (Continued): Digital signal Encoding Formats: I. NonReturn-to-Zero-Level (NRZ-L) Encoding: A negative voltage is equated with binary 1 and a positive voltage with binary 0. II./-Wakeel 29 Data Encoding 2. Digital Data, Analog Signals (Continued): I. Amplitude-Shift Keying (ASK): We can represent a unipolar periodic signal, v d (t), with unity amplitude and fundamental frequency w 0 as: We can represent the carrier signal as/

##### Copyright 2010 John Wiley & Sons, Inc3 - 1 Business Data Communications and Networking 10th Edition Jerry Fitzgerald and Alan Dennis John Wiley & Sons,

a clear beginning and ending –Computer networks send digital data using digital transmissions Data converted between analog and digital formats –Modem (modulator/demodulator): used when digital data is sent as an analog transmission –Codec (coder/decoder): used/circuit Signaling (encoding) –Defines how the voltage levels will correspond to the bit values of 0 or 1 –Examples: Unipolar, Bipolar RTZ, NRZ, Manchester –Data rate: describes how often the sender can transmit data 64 Kbps  once every 1/64000 of /

##### COMP 421 /CMPET 401 COMMUNICATIONS and NETWORKING CLASS 6.

pulse is a signal element –Binary data is encoded into signal elements Terms (1) Unipolar –All signal elements have same sign Polar –One logic state represented by positive voltage the/binary 0 An example of differential encoding (Data represented by changes rather than levels) NRZ NRZ pros and cons Pros –Easy to engineer –Makes good use of bandwidth Cons / timeslot. AMI AMI = Alternate Mark Inversion. This is the original method of formatting T1 data streams. In AMI a zero is always sent by doing nothing, /

##### Data and Computer Communications Tenth Edition by William Stallings Data and Computer Communications, Tenth Edition by William Stallings, (c) Pearson Education,

Binary data are transmitted by encoding each data bit into signal elements Terminology  Unipolar – all signal elements have the same sign  Polar – one logic state / to noise ratioData rateBandwidth Table 5.2 Definition of Digital Signal Encoding Formats (This table can be found on page 177 in the textbook) /is generated Summary  Digital data, digital signals Nonreturn to zero (NRZ) Nonreturn to zero (NRZ) Multilevel binary Multilevel binary Biphase Biphase Modulation rate Modulation rate Scrambling /

##### Copyright 2010 John Wiley & Sons, Inc3 - 1 Business Data Communications and Networking 10th Edition Jerry Fitzgerald and Alan Dennis John Wiley & Sons,

a clear beginning and ending –Computer networks send digital data using digital transmissions Data converted between analog and digital formats –Modem (modulator/demodulator): used when digital data is sent as an analog transmission –Codec (coder/decoder): used/circuit Signaling (encoding) –Defines how the voltage levels will correspond to the bit values of 0 or 1 –Examples: Unipolar, Bipolar RTZ, NRZ, Manchester –Data rate: describes how often the sender can transmit data 64 Kbps  once every 1/64000 of /

##### Signal Encoding Lesson 05 NETS2150/2850

Signal spectrum Bandwidth requirement Presence of dc component Digital-to-Digital Encoding Schemes 3 Broad Categories: Unipolar, Polar, and Bipolar -Nonreturn to Zero-Level (NRZ-L) -Nonreturn to Zero Inverted (NRZI) -Manchester -Differential Manchester -Bipolar -AMI -B8ZS -HDB3 /Odd Even - 000- +00+ + 000+ -00- B8ZS and HDB3 Change of polarity Recap of Digital Signal Encoding Formats 1 NRZL High level Low level NRZI No transition at start of interval transition Bipolar-AMI No line signal +ve line signal/

##### DIGITAL TRANSMISSION SYSTEMS.

) Noise immunity Error detection Clocking capability No added complexity Line Codes for PCM Unipolar NRZ -- Stays positive and does not return to level 0 during binary 1 cell. Bipolar NRZ -- 2 non zero voltages i.e. positive for 1 and negative for/ medium for PCM could be wire pair, coaxial cable, fiber-optic cable, and wideband radio media. The PCM multiplex format was first applied to wire-pair cable. *Transmission limitations of Medium: Each medium has transmission limitations brought about by impairments/

##### 5 Digital Encoding and Data Transmission Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Objectives  Give examples.

signal Unipolar digital signal  Bipolar digital signal Bipolar digital signal Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Non-Return to Zero (NRZ) Permission granted to reproduce for educational use only.© /in which a digital signal is not synchronized with a reference signal.  Binary Coded Decimal (BCD)  A binary number format in which each number is represented as a four-digit binary code. Glossary Permission granted to reproduce for educational use only.©/

##### Shiv Kalyanaraman Google: “Shiv RPI”

Multilevel binary 1 0 1 1 0 0 T 2T 3T 4T 5T +V -V NRZ-L Unipolar-RZ Bipolar-RZ Manchester Miller Dicode NRZ PCM waveforms: Selection Criteria Criteria for comparing and selecting PCM waveforms: Spectral characteristics (power/ Inter-Symbol Interference (ISI) Due to the filtering effect of transmitter, channel and receiver, symbols are “smeared”. estimated symbol Format Detect Demod. & sample Impact of AWGN Impact of AWGN & Channel Distortion Receiver job Demodulation and sampling: Waveform recovery and /

##### Pulse Code Modulation (PCM) 1 EE322 A. Al-Sanie. Encode Transmit Pulse modulate SampleQuantize Demodulate/ Detect Channel Receive Low-pass filter Decode.

bit duration Tb=Ts/l)‏ Encode Pulse modulate SampleQuantize Pulse waveforms (baseband signals)‏ Bit stream (Data bits)‏ Format Digital info. Textual info. Analog info. source Mapping every data bits to a symbol out of M symbols and transmitting a baseband waveform/ 0 -V 1 0 1 1 0 0 T 2T 3T 4T 5T +V -V +V -V +V 0 -V NRZ-L Unipolar-RZ Bipolar-RZ Manchester Miller Dicode NRZ 12 EE322 A. Al-Sanie PCM waveforms … Criteria for comparing and selecting PCM waveforms: – Spectral characteristics (power spectral density and /

##### Industrial Automation Automation Industrielle Industrielle Automation

File Transfer,...) Application Presentation Definition and conversion of the protocols 6 data formats (e.g. ASN 1) Session Management of connections 5 (e./ Send, Receive, Collision Modulation Baseband, Carrier band, Broadband Coding/Decoding Binary, NRZ, Manchester,.. Synchronisation Bit, Character, Frame Flow Control Handshake Interface Binary bit, /may not contain DC components cheap not efficient Electrical: Resistive (direct) coupling Unipolar, unbalanced Bipolar, unbalanced + Us Coax Ru + Us Zw Zw Rd /

##### Digital Communications I: Modulation and Coding Course Term 3 – 2008 Catharina Logothetis Lecture 2.

Receive Low-pass filter Decode Pulse waveforms Bit stream Format Digital info. Textual info. Analog info. Textual info. Analog info. Digital info. source sink Formatting and transmission of baseband signal Lecture 25 Format analog signals To transform an analog waveform into a/0 1 1 0 0 T 2T 3T 4T 5T +V -V +V -V +V 0 -V NRZ-L Unipolar-RZ Bipolar-RZ Manchester Miller Dicode NRZ Lecture 219 PCM waveforms … Criteria for comparing and selecting PCM waveforms: Spectral characteristics (power spectral density and /

##### Modulation, Demodulation and Coding Course Period 3 - 2005 Sorour Falahati Lecture 2.

Detect Channel Receive Low-pass filter Decode Pulse waveforms Bit stream Format Digital info. Textual info. Analog info. Textual info. Analog info. Digital info. source sink 2004-01-24Lecture 25 Format analog signals To transform an analog waveform into a form that is/ 0 1 1 0 0 T 2T 3T 4T 5T +V -V +V -V +V 0 -V NRZ-L Unipolar-RZ Bipolar-RZ Manchester Miller Dicode NRZ 2004-01-24Lecture 227 PCM waveforms Criteria for comparing and selecting PCM waveforms: Spectral characteristics (power spectral density and/

##### EE 3220: Digital Communication Dr. Hassan Yousif Ahmed Department of Electrical Engineering College of Engineering at Wadi Aldwasser Slman bin Abdulaziz.

step in any DCS: Transforming the information source to a form compatible with a digital system Formatting and transmission of baseband signal Dr Hassan Yousif 4 Encode Transmit Pulse modulate SampleQuantize Demodulate/ Detect Channel Receive Low-pass filter/ 1 0 1 1 0 0 T 2T 3T 4T 5T +V -V +V -V +V 0 -V NRZ-L Unipolar-RZ Bipolar-RZ Manchester Miller Dicode NRZ PCM waveforms … Dr Hassan Yousif 19 Criteria for comparing and selecting PCM waveforms: Spectral characteristics (power spectral density and/

##### 2004 June, HK Industrial Automation Automation Industrielle Industrielle Automation 3. Industrial Communication Systems Physical Layer 3.3.2 Niveau physique.

by the end user (Mail, File Transfer,...) Definition and conversion of the data formats (e.g. ASN 1) Management of connections (e.g. ISO 8326) End/ - Industrial Automation Electrical: Resistive (direct) coupling Ru Rd Zw + Us - Us Unipolar, unbalanced Open Collector (unbalanced) Bipolar, unbalanced Rt Ut Rt Ut = 5 V (e/Message synchronisationRecognize a sequence of frames Session synchronisationRecognize a sequence of messages Clock +NRZ Data +Framing Data in Manchester II Start-sync (Violation) Stop-sync (/

##### DIGITAL MODULATIONS. ©2000 Bijan Mobasseri2 Why digital modulation? l If our goal was to design a digital baseband communication system. We have done.

time or frequency domain l There is another representation space that portrays signals in more intuitive format l In this section we develop the idea of signals as multidimensional vectors ©2000 Bijan Mobasseri6/ was obtained from a polar signal by carrier modulation l We know the bandwidth of polar NRZ using square pulses was B T =R b. l It doesn’t take much to / of two RF streams l BFSK can be thought of superposition of two unipolar signals, one at f 1 and the other at f 2 + ©2000 Bijan Mobasseri108 Modeling /

##### Qassim University College of Engineering Electrical Engineering Department Electronics and Communications Course: EE320 Communications Principles Prerequisite:

, a sample quantized into one of 256 levels may be represented by an 8-bit codeword. Line Coding (a) In unipolar NRZ signaling, symbol 1 is represented by transmitting a pulse of amplitude A for the duration of the symbol, and symbol 0 / 3. Efficient exchange of increased channel bandwidth for improved signal-to- noise ratio, obeying an exponential law. 4. A uniform format for the transmission of different kinds of baseband signals, hence their integration with other forms of digital data in a common network/

##### UNIT-1 SOURCE CODING SYSTEMS 1.  Source: analog or digital  Transmitter: transducer, amplifier, modulator, oscillator, power amp., antenna  Channel:

over the same medium in the analog domain.  Using digital techniques, it is possible to combine both format for transmission through a common medium  Encryption and privacy techniques are easier to implement  Better overall performance / Codes ◦ Polar - Send pulse or negative of pulse ◦ Unipolar - Send pulse or a 0 ◦ Bipolar  Represent 1 by alternating signed pulses  Generalized Pulse Shapes ◦ NRZ -Pulse lasts entire bit period  Polar NRZ  Bipolar NRZ ◦ RZ - Return to Zero - pulse lasts just half/

##### Unit 3 Physical Layer. OSI Model The Open Systems Interconnection (OSI) model is a reference framework for understanding data communications between any.

coming from a digital computer or some other source cannot be put directly on the network medium, because the format of this signal is not suitable for its direct transmission. This takes place at the physical layer and it/. The various formats used are called as line codes. The formats or line codes used commonly in networking are: – Non-return to zero (NRZ) and return to zero (RZ) unipolar formats. – NRZ and RZ polar format – Non-return to zero bipolar formats – Manchester format – Differential Manchester/

##### S Transmission Methods in Telecommunication Systems (4 cr)

speech/video coding standards Pulse Coded Modulation (PCM) PCM is a method by which analog message can be transformed into numerical format and then decoded at the receiver transmitter LP-filtering sampling quantization PAM/HDB-3 Channel receiver LP-filtering PAM/HDB-3 /to use PCM then?? regenerative digital repeaters digital multiplexing etc! channel noise Some line codes Unipolar [0,A] RZ and NRZ Polar [-A/2,A/2] RZ and NRZ Bipolar [-A/2,0,A/2] AMI Split-Phase Manchester Code rate reduced by n Split/

##### A digital signal is a sequence of discrete discontinuous voltage pulses. Each pulse is a signal element (symbol). Binary data are transmitted by encoding.

Data/Signal r = d / s Data element – The actual information/data/message to be delivered Signal element – The right format of signals or suitable signal types used to carry the data element (actual data) d = data element s = signal element/ of the signal. Use transitions and changes as mechanisms to encode the data. Line coding schemes UNIPOLAR NRZ scheme (Non Return to Zero) Main problem of NRZ: No timing information is carried to provide correct synchronisation at the receiver. (Not knowing when one/

##### 1 □Basic scheme of PCM system □Quantization □Quantization Error □Companding □Block diagram & function of TDM-PCM communication system.

signal along the channel path. □ Efficient exchange between B T and SNR. □ Uniform format for different kind of base- band signals. □ Flexible TDM. 29 Cont’d… □ /Signals to Transmit Digital Data □Bits must be changed to digital signal for transmission □Unipolar encoding □Positive or negative pulse used for zero or one □Polar encoding □Uses two/voltage for one value and positive for the other. 47 Non-Return to Zero Inverted (NRZ-I) □ Nonreturn to zero inverted on ones □ Constant voltage pulse for duration of /

##### 4.2 Digital Transmission Outlines □ Pulse Modulation □ Pulse Code Modulation □ Delta Modulation □ Line Codes.

along the channel path. □ Efficient exchange between B T and SNR. □ Uniform format for different kind of base- band signals. □ Flexible TDM. continue… □ Secure communication/ to Transmit Digital Data □Bits must be changed to digital signal for transmission □Unipolar encoding □Positive or negative pulse used for zero or one □Polar encoding □Uses/ □Bipolar encoding □+, -, and zero voltage levels are used Non-Return to Zero-Level (NRZ-L) □ Two different voltages for 0 and 1 bits. □ Voltage constant during bit /

##### 4.2 Digital Transmission Outlines □ Pulse Modulation □ Pulse Code Modulation □ Delta Modulation □ Line Codes.

along the channel path. □ Efficient exchange between B T and SNR. □ Uniform format for different kind of base- band signals. □ Flexible TDM. Cont’d… □ Secure/Signals to Transmit Digital Data □Bits must be changed to digital signal for transmission □Unipolar encoding □Positive or negative pulse used for zero or one □Polar encoding □Uses/ □Bipolar encoding □+, -, and zero voltage levels are used Non-Return to Zero-Level (NRZ-L) □ Two different voltages for 0 and 1 bits. □ Voltage constant during bit interval/

##### 1 Chapter 3. Physical Layer Business Data Communications and Networking Fitzgerald and Dennis, 7th Edition Copyright © 2002 John Wiley & Sons, Inc.

a bit value of 0 or 1. Unipolar signal voltages either vary between 0 and a positive value or between 0 and some negative / returns to the 0 voltage level after sending a bit. In non return to zero (NRZ), the signals maintains its voltage at the end of a bit. Ethernet uses Manchester encoding in/Service). Modem communications use the telephone network to send digital data that has been converted into an analog format. 38 Carrier Waves Modems use carrier waves to send information (Figure 3-13). Each wave has /

##### Chapter 3. Physical Layer

a bit value of 0 or 1. Unipolar signal voltages either vary between 0 and a positive value or between 0 and some negative value/signal returns to the 0 voltage level after sending a bit. In non return to zero (NRZ), the signals maintains its voltage at the end of a bit. Ethernet uses Manchester encoding in /). Modem communications use the telephone network to send digital data that has been converted into an analog format. Carrier Waves Modems use carrier waves to send information (Figure 3-13). Each wave has three /

##### 4.2 Digital Transmission Pulse Modulation (Part 2.1)

faithfully) Cont’d... Six factors must be considered when selecting a line encoding format; transmission voltage & DC component Duty cycle Bandwidth consideration Clock and framing bit/ Signals to Transmit Digital Data Bits must be changed to digital signal for transmission Unipolar encoding Positive or negative pulse used for zero or one Polar encoding Uses two / one value and positive for the other. Non-Return to Zero Inverted (NRZ-I) Nonreturn to zero inverted on ones Constant voltage pulse for duration of/

##### Pulse Code Modulation (PCM). Example Solution In the previous example we have 8-quantization levels (to encode with 3-bits) from code number 0 to 7 (from.

bit = 193 bits Where: 1 F is one frame synchronization bit Bit rate for T 1 channel =(193  8K)=1.544 Mb/s T1 TDM format for one frame. Multiplexing T 1 -Lines 4-T 1 lines are multiplexed to generate one T 2 line. M 12 multiplexer adds 17 bits for/codes) Line Codes 1 1 1 111111 000000 Examples On/Off (unipolar) – “1” send p(t), “0” nothing – Return to zero (RZ) – Non-Return to Zero (NRZ) Polar (bipolar) – “1” send p(t), “0” send -p(t) Bipolar (RZ) Bipolar (NRZ) 1 1 1 0 0 1 1 Bipolar Alternate Mark Inversion /

##### Digital Line Encoding Converting standard logic level to a form more suitable to telephone line transmission. Six factors must be considered when selecting.

transmission. Six factors must be considered when selecting a line encoding format; 1.transmission voltage & DC component 2.Duty cycle 3.Bandwidth/Digital Signals to Transmit Digital Data –Bits must be changed to digital signal for transmission –Unipolar encoding Positive or negative pulse used for zero or one –Polar encoding Uses two voltage levels/ for one value and positive for the other. Non-Return to Zero Inverted (NRZ-I) Nonreturn to zero inverted on ones Constant voltage pulse for duration of bit/

##### TCP/IP 陳彥文. YWChen-TCP/IP  何謂資料？  IEEE 對 Data 的定義為 -- A representation of facts, concepts, or instructions in a formalized manner suitable for communication,

, EBCDIC 碼、語音的 A-Low 、 u-Low 、視訊的 MPEG 等。  0 與 1 在傳輸線上的表現方式： 1 0 +Voltage 0 Volts 較常用的表現方式則包括 Unipolar, Bipolar, RZ, 及 NRZ 幾種 YWChen-TCP/IP Data Conversion Uncompres. Compres. Data Conversion Transmission Sampling Data conv./ Uncompres. Data conv./ Compres. Filter /- Flag pattern 為單一 01111110 的資訊能順利傳送 ，不會混淆 方法 - 傳送資料時，逢五個連續 1 則插入一個 0 YWChen-TCP/IP Layer 2 – EtherFrame Format YWChen-TCP/IP Layer 2 – Ethernet Frame Type Frame type valueMeaning 0000-05DCReserved 0800Internet Protocol 0805X.25 6559Frame Relay/

##### Wireless Sensor Systems: Security Implications for the Industrial Environment Dr. Peter L. Fuhr Chief Scientist RAE Systems, Sunnyvale, CA

. FDMA, TDMA and CDMA ISA Wireless Security, P. Fuhr 40 Binary Signaling Formats Used to Improve Digital Signal Reception and Decision NRZ: Non-Return to Zero RZ: Return to Zero Unipolar: Only one side of 0V Bipolar: Both sides of 0V Manchester: Bi-Phase/ Optional element in an H.323 conference. Gateways bridge H.323 conferences to other networks, communications protocols, and multimedia formats. Gateways are not required if connections to other networks or non-H.323 compliant terminals are not needed. GHz: /

##### 1 An Najah National University Telecommunication Engineering Department Digital Communications 69342 TDM Dr. Allam Mousa Sec_2_TDM.

the transmission path. 3)Efficient exchange of increasing channel B.W for improved SNR, obeying an exponential law. 4)A uniform format for the transmission of different kinds of baseband signals. 5)Easy to drop or reinsert a source in the TDM system. 6/sec. {depending on format} 1 sample has n bits 2 W sample ??? (n bits *2W sample)/ (1 sample) = 2nW bits /sec is the data rate. 2 20Sec_2_TDM Small error requires large B.W. Error is exchanged with bandwidth. B.W =1/T = 2nW for Unipolar NRZ =knW for some /

##### Copyright 2005 John Wiley & Sons, Inc3 - 1 Physical and Data Link Layers.

go undetected –No transition  en error took place Copyright 2005 John Wiley & Sons, Inc3 - 21 Digital Transmission Types Unipolar Bipolar NRZ Bipolar RZ Manchester Copyright 2005 John Wiley & Sons, Inc3 - 22 Analog Transmission of Digital Data A well known example –/and converted back to sound waves Sending digital data over POTS –Use modems to convert digital data to an analog format One modem used by sender to produce analog data Another modem used by receiver to regenerate digital data Copyright 2005/

##### COMMUNICATION SYSTEM EECB353 Chapter 5 Part V DIGITAL TRANSMISSION LINE ENCODING PROPERTIES Intan Shafinaz Mustafa Dept of Electrical Engineering Universiti.

are not canceled by the negative voltages. b) The positive voltages are canceled by any negative voltage. Unipolar Bipolar Properties of Line Coding 2. Duty cycle – NRZ maintained the binary pulse entire bit time, while RZ the active time of the binary pulse is less /whether the bit is a 1 or a 0. BPRZ-AMI encoding provides sufficient transition to ensure clock synchronization. Line Coding Summary Encoding Format Minimum BW Average DCClock Recovery UPNRZ f b /2*+ V /2 Poor BPNRZ f b /2*0 V* Poor UPRZ fbfb/

##### LECTURE № 4. Methods and devices of modulation in radio and TV broadcasting 1. Modulation in analog radio and television broadcasting systems - AM and.

(Hertz) S/N =signal-to-noise power ratio (dimensionless) Bandwidth and information capacity Binary data sequence signaling t 0000011111 Unipolar (On-off) Polar (NRZ) Return-to-zero (RZ) Bipolar TbTb A Digital modulation : Amplitude Shift Keying (ASK) Frequency-shift keying (FSK/= 2, 4, 8, 16,.... I/Q Modulation Polar display—Magnitude and phase represented together “I-Q” format—Polar to rectangular conversion Modulated signal can to present by sum of two quadrature component QPSK: quadrature phase shift /