Quadrature phase shift keying (QPSK) is another modulation technique, and it’s a particularly interesting one because it actually transmits two bits per symbol. Following equations or formula are used for VSAT Bandwidth Calculator. A secondary goal of such a modulation scheme is to achieve high bandwidth efficiency with minimum signal power. Documentation All; Examples; Functions; Blocks; Apps; Videos; Answers; Main Content . Note also that the PRK signal can also be obtained in the context of an ASK system modulated by a polar baseband signal. The bandwidth of the FSK signal is therefore 21f C2B D 150 kHz C200 kHz D 350 kHz: 4. The bandwidth is B = 8 × 1000 = 8000. The bandwidth of the carrier at the -12 dB points is approx 1.28 times the symbol rate. Noiseless Channel : Nyquist Bit Rate – For a noiseless channel, the Nyquist bit rate formula defines the theoretical maximum bit rate. DVB-T Radar DVB-T Transmitters List DVB-T Bitrate Calculator DVB-T2 Bitrate Calculator ATSC 3.0 Bitrate Calculator ISDB-T Bitrate Calculator. Formula: SR = DR / (m x CRv x CRrs) DVB-S Carrier bandwidth. In other words, a QPSK symbol doesn’t represent 0 or 1—it represents 00, 01, 10, or 11. If you apply this formula on the two other data rates given in the data sheet (2.4kHZ and 10 kHz) you will get much closer to what is measured by using carson rule. the data rate 1 T must be less than 11 Mbits/second. PSK is of two types, depending upon the phases the signal gets shifted. What is QAM (Quadrature Amplitude Modulation)? Status Not open for further replies. They are − Calculator shows maximum throughput which are reachable in … Such published performance results apply to binary phase-shift keying (BPSK) or quadrature PSK (QPSK) modulation, as is typically used in deep space missions. what is a satellite   Antenna G/T frequencies are 150 kHz apart, determine the bandwidth. The dispersion coefficient of the fiber is D = 17e-6 sec/m/m. What is the symbol rate and bit rate? GMSK –Practical GMSK Data Transmission 2 Application Note 1998 MX COM, INC. www. VSAT network architecture  Therefore, the binary information must be encoded entirely in the phase of the output signal. Joined Jul 18, 2012 Messages 2 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,294 BW=Rb*(1+r)/(l*FEC) l=2 for QPSK . Draw a diagram showing the frequency spectrum of the QPSK signal, labelling any important frequencies. Pass an FSK signal … The output is a baseband representation of the modulated signal. For the RF components, 21f D 150 kHz. OOK to 64QAM gives you 12x more bandwidth. The bandwidth is B = 8 × 1000 = 8000. 11) Refer to image below, describing relationship between data rate and bandwidth in my experience. Bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. Quadrature Phase Shift Keying ( QPSK ) is a form of Phase Shift Keying in which two bits are modulated at once. QPSK- Quadrature Phase Shift Keying. equations used for VSAT Bandwidth Calculator or Satellite Bandwidth Calculator. Offset quadrature phase‐shift keying (OQPSK) is a variant of QPSK, in which the information stream of the in‐phase (I) component is delayed by half of the symbol time from that of the quadrature (Q) component 6. The bandwidth of the baseband signal (to the first null) is given by B D 1=.2T/. MODCOD, FEC, SR, sps, QPSK, APSK. Carson’s Rule to determine the BW for an FSK signal: where OBW is the occupied bandwidth. It is measured in bits per second and is represented as, The bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. BPSK=1, QPSK=2, 8PSK=3, 8QAM =3, 16QAM=4 etc . mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. This way, the formula can be simplified to the … VSAT internet  In other words, QAM transmits information by changing both the amplitude and phase of a carrier wave, thereby doubling the effective bandwidth. Explaining your answers, determine the bandwidth if the modulation method had been For example, instead of a phase shift of 180 degree, as allowed in BPSK, a common encoding technique, known as QPSK uses phase shifts of multiples of 90 degrees i.e. Status Not open for further replies. 4 Other formulas that you can solve using the same Inputs, Bandwidth of PSK=(1+Modulation factor)*Baud rate. 2/3 4096 QPSK Gray Approximate LLR 4/5 16384 8-PSK Anti-Gray Hard decision LLR 16-APSK DVB-S2 32-APSK The performance of the AR4JA LDPC codes on a binary-input additive white Gaussian noise (AWGN) channel is well-documented [1,2]. m = modulation factor (transmission rate bits per symbol). 7.3.2 Offset Quadrature Phase-Shift Keying. The total bandwidth required for PM can be determined from the bandwidth of the audio signal: BPM = 2(1 + β) B Chapter's Questions: P5-1: Calculate the baud rate for the given bit rate and type of modulation. The following values are supported QPSK, 16QAM, 64QAM. 2.3 Differentially Encoded QPSK and Offset (Staggered) QPSK ... bandwidth-efficient modulation methods that directly modulated the carrier were being developed, which, along with improved data formatting methods (e.g., packet transfer frame telemetry) to handle the multiple channel separa-tion problem, eliminated the need for subcarriers. ?en for the system bandwidth and in the following sections have been first four DPSSs from the set de- W = .04, where N is the number set and W is a bandwidth shaping 0.5. 2000 bps, FSK S= N/r = 2000 baud b. Jun 16, 2013 #2 A. AAAm Newbie level 2. Bandwidth of FSK=((1+Modulation factor)*Baud rate)+(Level of FSK-1)*(2*Difference in frequency), Bandwidth of FSK=((1+Modulation factor)*Baud rate)+(2*Difference in frequency), Bandwidth of ASK=(1+Modulation factor)*(Bit rate/Number of bits), Bandwidth of ASK=(1+Modulation factor)*Baud rate, Attenuation when power of 2 signals are given, Attenuation when voltage of 2 signals are given, Bit rate of raised cosine filter when time period is given, The bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. For the RF components, 21f D 150 kHz. The bit period in the baseband signal is T D 1=200000 seconds, and the baseband pulses are rectangular. 10) So the effective data rate is 2 Mbps for a bandwidth of 1 MHz at passband (in my experience). Explaining your answer, calculate the bandwidth of the QPSK signal. Quadrature Phase Shift Keying ( QPSK ) is a form of Phase Shift Keying in which two bits are modulated at once. … Moving data from one point […] Stripline Impedance calculator dBm to Watt converter OUTPUTs: Symbol Rate = 682.67 KSPS, Occupied BW = 0.8874 MHz. The bit period in the baseband signal is T D 1=200000 seconds, and the baseband pulses are rectangular. Calculate the number of levels (different frequencies), the baud rate, and the bandwidth. Thus the data bit must be at least T 9 0 1 0 8 seconds long, i.e. Bandwidth of PSK calculator uses Bandwidth of PSK=(1+Modulation factor)*Baud rate to calculate the Bandwidth of PSK, The bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. LTE uses OFDMA as it's base multiple access scheme, leveraging Orthogonal Frequency Division Multiplexing (OFDM). Quadrature Phase Shift Keying is a digital modulation method. MSK signals will have a narrower bandwidth than general FSK signals. The bandwidth of the baseband signal (to the first null) is given by B D 1=.2T/. It is digital modulation technique. 4000 bps, ASK S= N/r = 4000 baud c. 6000 bps, QPSK r = 2 >> S= N/r = 6000/2= 3000 baud Keywords … Calculate Symbol Rate and Baud Rate, equation, examples and online calculator. 5.16 To use this online calculator for Bandwidth of PSK, enter Baud rate (r) and Modulation factor (d) and hit the calculate button. or how we can calculate the bandwidth of QPSK modulation (Formula of QPSK bandwidth) - How we can calculate the bandwidth of GEO satellite?? In Quadrature Phase Shift Keying, two information bits are modulated at once, unlike Binary Phase Shift Keying where only one bit is … FSK is basically FM where the message signal is a square wave. This is a tool that we use to quickly compare the spectral performance associated with various FEC/Modulation combinations. Calculate the number of levels (different frequencies), the baud rate, and the bandwidth. Figure 7.17a shows the input binary signal m(t) in polar form for a stream of bits. DVB-S/S2 Bitrate Calculator DVB-S2X Bitrate Calculator Azimuth & Elevation Coverage maps Satellite launches. m = modulation factor (transmission rate bits per symbol). Explaining your answers, determine the bandwidth if the modulation method had been How to calculate Bandwidth of PSK using this online calculator? Here is how the Bandwidth of PSK calculation can be explained with given input values -> 1050 = (1+20)*50. When used for analog signals, frequency modulation and amplitude modulation lead to continuous variations in the frequency or amplitude of a carrier wave. 2.1 Dispersion and Bandwidth Efficient Schemes: NRZ, QPSK and DQPSK NRZ intensity modulation format is widely used at 10 Gbps right now. As a consequence, an OQPSK signal shows a maximum envelope change of 3 dB (70%) compared to the 100% change for QPSK. The comm.QPSKModulator object modulates using the quadrature phase shift keying method. Visualize Effects of Frequency-Selective Fading FSK Modulation in Fading Channel. Bandwidth: Bandwidth is often used as a synonym of data transfer rate. Share: Facebook Twitter … The prime goal of spectrally efficient modulation is to optimize bandwidth efficiency, which is defined as the ratio of the data rate to the channel bandwidth (in b/s/Hz). Quadrature Phase Shift Keying QPSK Differential Quadrature Phase Shift Keying DQPSK Pi/4 Differential Quadrature Phase Shift Keying Pi/4 DQPSK Quadrature Amplitude Modulation QAM Table 1: Modulation Formats. In other words, QPSK, vis-à-vis BPSK, halves the bandwidth required for given bit rate. Jun 16, 2013 #2 A. AAAm Newbie level 2. Combining the packet telemetry format with any of the direct … If you’re going from QPSK to 64 QAM you’ll get 300% more bandwidth or 3x. BPSK=1, QPSK=2, 8PSK=3, 8QAM =3, 16QAM=4 etc . Figure 5.8 shows the allocation of frequencies and bandwidth. Satellite Bandwidth Calculator. When modulation techniques are used for digital communication, the variations applied to the carrier are restricted according to the discrete information being transmitted. Calculations for DVB-S2, DVB-S2X and DVB-S standards, calculate bitrate and bandwidth, netto bitrate, up to 32APSK. Calculator shows maximum throughput which are reachable in … As mentioned QPSK stands for Quadrature Phase Shift Keying. pi by 2. From this you can determine 64 QAM provides 50% more bandwidth than 16 QAM (12 divided by 8). MCS (Modulation and Coding Scheme) depends on channel quality (e.g. GMSK –Practical GMSK Data Transmission 2 Application Note 1998 MX COM, INC. www. Thus the data bit must be at least T 9 0 1 0 8 seconds long, i.e. Continuing use of the site implies consent. Bandwidth defines how many radio resources are available to transmit data. Explaining your answer, calculate the bandwidth of the QPSK signal. Modulation factor is used for the modulation process and filtering process and has the value of either 0 or 1. QPSK allows the signal to carry twice as much Assumptions. QPSK is bandwidth efficient as each signal point represents two bits. Find: The data rate that can be used and the bandwidth that is needed. Find: The data rate that can be used and the bandwidth that is needed. The power spectral densi- to these sequences are shown in SYSTEM OVERVIEW QPSK transmitter may be repre- = &")p(t - nTs), (1) represent the complex data values The bandwidth of the FSK signal is therefore 21f C2B D 150 kHz C200 kHz D 350 kHz: 4. FEC Rate = 0.75 (for 3/4), Roll off factor = 0.30 It is digital modulation technique. frequencies are 150 kHz apart, determine the bandwidth. 9) With an IQ rate of 1 Mega samples per second, I can send 2 bits on each sample (because it is QPSK). Bitrates Calculators Satellite segment optimalizator MPEG-TS tools. For optimum use of available satellite power, an unbalanced QPSK (UQPSK) modulator is often used. Following equations or formula are used for VSAT Bandwidth Calculator. The bandwidth of the carrier at the -3.8 dB points is approx the same as the symbol rate. The following values are supported QPSK, 16QAM, 64QAM. What is QAM (Quadrature Amplitude Modulation)? To apply QPSK modulation: Create the comm.QPSKModulator object and set its properties. It is measured in bits per second. ... Bitrates Calculators Satellite segment optimalizator MPEG-TS tools. Manufacturers directory DSNG directory Jobs. Quadrature Phase Shift Keying QPSK Differential Quadrature Phase Shift Keying DQPSK Pi/4 Differential Quadrature Phase Shift Keying Pi/4 DQPSK Quadrature Amplitude Modulation QAM Table 1: Modulation Formats . Creation. Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave).The modulation is accomplished by varying the sine and cosine inputs at a precise time. In a QPSK modulator, two data streams simultaneously modulate a carrier signal. The design and simulation for such a modulator will be shown here, along with methods for demodulating such signals. QAM (Quadrature Amplitude Modulation) is defined as the modulation technique which is the combination of phase and amplitude modulation of a carrier wave into a single channel. But Eb N0 PrT N0 13 " 52. Symbol and Baud rates are the number of symbol changes per second made to a signal. On this channel you can get education and knowledge for general issues and topics You can SPONSOR US by sign up by clicking on this link. The baud rate is S = 3 MHz/3 = 1000 Mbaud. Clearly we also need a (null-to-null) bandwidth of 22 MHz. Assume that the QPSK signal has a carrier frequency is 1800 MHz and the bit rate is 270 kbit/s. Communications channels in satellite-communications (satcom) systems, as well as communications … The baud rate is S = 3 MHz/3 = 1000 Mbaud. Solution We can have L = 23 = 8. mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. Solution: Need Q 2Eb N0 1 0 7 or Eb N0 11 "3dB or Eb N0 13 52. Bandwidth of PSK and is denoted by BW symbol. Symbol rate: In Digital Communication, the symbol rate means that the changes of symbol per second (signaling events or waveform changes) through a digital modulated signal transmission path. QPSK for Satellite Page 1 Satellite/LMDS QPSK Bandwidth Calculator Revision 6 Nov-01 Option 1: Bandwidth to Multiplex Information Rate Calculation ENTER OCCUPIED BANDWIDTH 34.00 MHz Assumes 188/204 Reed-Solomon and .35 Roll-off factor per ETSI EN 300 421 SYMBOL DATA USABLE INFO RATE WITH R/S AND FEC @ RATE RATE NO FEC 7/8 5/6 3/4 2/3 1/2 25.185185 50.370370 … The difference between QPSK and BPSk lies in the logical representation of data. This page covers VSAT Bandwidth Calculator or Satellite Bandwidth Calculator. VSAT Bandwidth Calculator Formula or Equations. Alternatively single-sideband BPSK would have the same rate in bits per second per hertz but would have a more difficult job of recovering the carrier frequency and phase. How can I calculate the occupied bandwidth of a digital frequency modulated signal (2FSK, 2GFSK, 4FSK, 4GFSK)? Different modulation formats will require different bandwidths for the same data rate. BitRate = 2 * … or how we can calculate the bandwidth of QPSK modulation (Formula of QPSK bandwidth) - How we can calculate the bandwidth of GEO satellite?? For FM modulation, the bandwidth is approximately 2*(df + fm) where df is the maximum frequency deviation and fm is the frequency of the message. of QPSK over BPSK is that the the data rate is twice as high for the same bandwidth. QPSK is bandwidth efficient as each signal point represents two bits. Share: Facebook Twitter … Satellite/VSAT Bandwidth Calculator EXAMPLE: INPUTS: Data rate = 1024 Kbps, Modulation Order = 2 (QPSK), FEC Rate = 0.75 (for 3/4), Roll off factor = 0.30 OUTPUTs: Symbol Rate = 682.67 KSPS, Occupied BW = 0.8874 MHz . 10 00 11 01 Constellation Diagram of QPSK Dibit Phase 00 0 01 90 10 180 11 270 Dibit (2 bits) Baud rate refers to the number of signal or symbol changes that occur per second. Formula: SR = DR / (m x CRv x CRrs) DVB-S Carrier bandwidth. Tools. OFDM splits the carrier frequency bandwidth into several small subcarriers spaced at 15 kHz intervals, and modulates individual subcarriers using QPSK, 16-QAM, or 64-QAM modulation. Open Script. Solution: Symbol Rate = Bandwidth / 1.35 = 5 (MHz) / 1.3 = 5* 1000 / 1.35 = 3703.7 a. DVB-C Bitrate Calculator. MCS (Modulation and Coding Scheme) depends on channel quality (e.g. Quadrature phase shift keying (QPSK) is another modulation technique, and it’s a particularly interesting one because it actually transmits two bits per symbol. to NF, Overview of VSAT System   In this method, the phase of the carrier waveform is changed according to the digital baseband signal. QPSK has the same pulse requirements as BPSK. Bandwidth Calculator This calculator can be used to compute a variety of calculations related to bandwidth, including converting between different units of data size, calculating download/upload time, calculating the amount of bandwidth a website uses, or converting between monthly data usage and its equivalent bandwidth. SINR) and defines how many bits can be carried by a single Resource Element (RE). Services. … This tool assumes power equivalent bandwidth, or that you have adequate power to close the link at the FEC/MOD combinations you select. Bandwidth of PSK calculator uses Bandwidth of PSK=(1+Modulation factor)*Baud rate to calculate the Bandwidth of PSK, The bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. Alternatively single-sideband BPSK would have the same rate in bits per second per hertz but would have a more difficult job of recovering the carrier frequency and phase. Draw a diagram showing the frequency spectrum of the QPSK signal, labelling any important frequencies. pi by 2. If the bandwidth is 5MHz and others options are DVB, PAL, FEC=3/4, QPSK Modulation. The bandwidth of the carrier at the -12 dB points is approx 1.28 times the symbol rate. Figure 5.8 shows the allocation of frequencies and bandwidth. In other words, QAM transmits information by changing both the amplitude and phase of a carrier wave, thereby doubling the effective bandwidth. QPSK for Satellite Page 1 Satellite/LMDS QPSK Bandwidth Calculator Revision 6 Nov-01 Option 1: Bandwidth to Multiplex Information Rate Calculation ENTER OCCUPIED BANDWIDTH 34.00 MHz Assumes 188/204 Reed-Solomon and .35 Roll-off factor per ETSI EN 300 421 SYMBOL DATA USABLE INFO RATE WITH R/S AND FEC @ RATE RATE NO FEC 7/8 5/6 3/4 2/3 1/2 25.185185 50.370370 … This means that the carrier frequencies must be 1 MHz apart (2Δf = 1 MHz). of QPSK over BPSK is that the the data rate is twice as high for the same bandwidth. The bandwidth of the carrier at the -3.8 dB points is approx the same as the symbol rate. It is measured in bits per second. The rate of change (baud) in this signal determines the signal bandwidth, but the throughput or bit rate for QPSK is twice the baud rate. It is widely used for wireless LANs, RFID and Bluetooth communication.. Any digital modulation scheme uses a finite number of distinct signals to … But Eb N0 PrT N0 13 " 52. PSK technique is widely used for wireless LANs, bio-metric, contactless operations, along with RFID and Bluetooth communications. In QPSK the transitions take place every 2T b seconds. All values standardized by 3GPP are supported. For 2FSK / 2GFSK modulation the symbol rate is equal to the data rate, and unlike 4FSK / 4GFSK modulation there is only one deviation. It mentions formula or Parts of a satellite, ©RF Wireless World 2012, RF & Wireless Vendors and Resources, Free HTML5 Templates. Solution: Need Q 2Eb N0 1 0 7 or Eb N0 11 "3dB or Eb N0 13 52. Services. # 20830067.002 4800 Bethania … Bandwidth defines how many radio resources are available to transmit data. 5.16 It is measured in bits per second. Answer. Manufacturers directory … However, there is a 3dB advantage in using PRK over OOK. Assume that the QPSK signal has a carrier frequency is 1800 MHz and the bit rate is 270 kbit/s. Bandwidth of PSK calculator uses Bandwidth of PSK=(1+Modulation factor)*Baud rate to calculate the Bandwidth of PSK, The bandwidth of PSK is given is the amount of data that can be transferred from one point to another within a network in a specific amount of time. Solution We can have L = 23 = 8. In other words, you can use this tool to effectively create a power equivalent bandwidth … QPSK: 1-symbol 2-bit composition, where 2 bits and 4 statuses are assigned to the carrier wave phases π/4, 3π/4, 5π/4, and 7π/4. the data rate 1 T must be less than 11 Mbits/second. QPSK Modulation in Frequency-Selective Fading; Documentation All; Examples; Functions; Blocks; Apps; Videos; Answers; Trial Software; Trial Software; Product Updates; Product Updates; Resources . Phase Shift Keying (PSK) is the digital modulation technique in which the phase of the carrier signal is changed by varying the sine and cosine inputs at a particular time. Practically, an OQPSK modulated signal has many … Terrestrial. Symbol rate is indicate by symbols/second or baud (Bd) units. # 20830067.002 4800 Bethania … bandwidth required is also quite modest when compared with these other signalling schemes. This constant amplitude characteristic is the most important characteristic of PSK that distinguishes it from QAM. In other words, a QPSK symbol doesn’t represent 0 or 1—it represents 00, 01, 10, or 11. If this line of thinking is extended, PSK with eight or sixteen values is possible. INPUTS: Data rate = 1024 Kbps, Modulation Order = 2 (QPSK), Satellite frequency bands of operation   For example, an ITU-T V.22 modem uses QPSK to send data at 1200 bits per second over a dial-up phone line. The following figures show the effect of dispersion in a single mode fiber for NRZ modulation at 40 Gbps. Learn More × BPSK- Binary Phase Shift Keying The OQPSK constellation is as shown in Figure 5. It is measured in bits per second. In bandwidth-limited channels, spectrally efficient modulation schemes are often used to conserve bandwidth. Cable. As mentioned QPSK stands for Quadrature Phase Shift Keying. For example, instead of a phase shift of 180 degree, as allowed in BPSK, a common encoding technique, known as QPSK uses phase shifts of multiples of 90 degrees i.e. There is a variation of QPSK, known as offset QPSK (OQPSK), in which the in-phase and quadrature components are offset by one bit interval T b. The bandwidth available; Number of levels in digital signal; The quality of the channel – level of noise; Two theoretical formulas were developed to calculate the data rate: one by Nyquist for a noiseless channel, another by Shannon for a noisy channel. So there is no difference in bandwidth between the two. All values standardized by 3GPP are supported. Following is the list of useful converters and calculators. Noise temp. To provide a better shopping experience, our website uses cookies. On this channel you can get education and knowledge for general issues and topics You can SPONSOR US by sign up by clicking on this link. RF bandwidth and data rate are related by the modulation format. QAM (Quadrature Amplitude Modulation) is defined as the modulation technique which is the combination of phase and amplitude modulation of a carrier wave into a single channel. SINR) and defines how many bits can be carried by a single Resource Element (RE). Clearly we also need a (null-to-null) bandwidth of 22 MHz. OFDMA then assigns each user the bandwidth needed for their transmission, using a scheduler such … Joined Jul 18, 2012 Messages 2 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,294 BW=Rb*(1+r)/(l*FEC) l=2 for QPSK . As is seen across the dotted lines the phase changes are of ±π/2. In Figure 2, it can be seen that with QPSK, each of the four possible output phasors has exactly the same amplitude. QPSK allows the signal to carry twice as much The phase of the carrier remains the same when the input logic is the 1 but goes a phase shift when the logic is 0. Call the object with arguments, as if it were a function. Figure 4: The figure shows a QPSK waveform. To learn more about how System objects work, see What Are System Objects?. Satellite tutorial   Spectra and bandwidth of emissions (Question ITU-R 222/1) (1948-1951-1953-1956-1959-1963-1966-1970-1974-1978-1982-1986-1990-1994-1997-1999-2006) Scope This Recommendation gives definitions, analytical models and other considerations of the values of emission components for various emission types as well as the usage of these values from the standpoint of spectrum efficiency. Microstrip line impedance This means that the carrier frequencies must be 1 MHz apart (2Δf = 1 MHz). Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave).The modulation is accomplished by varying the sine and cosine inputs at a precise time. It is measured in bits per second is calculated using. 2.3 Differentially Encoded QPSK and Offset ... bandwidth-efficient modulation methods that directly modulated the carrier were being developed, which, along with improved data formatting methods (e.g., packet transfer frame telemetry) to handle the multiple channel separa-tion problem, eliminated the need for subcarriers. Satellite/VSAT Bandwidth Calculator EXAMPLE: