# MSK (Minimum Shift Keying) CML Microcircuits, MSK (Minimum Shift Keying) Datasheet

#### MSK (Minimum Shift Keying)

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#### MSK (Minimum Shift Keying) Summary of contents

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APPLICATION MSK and its Application to Wireless Data Transmission 1. Introduction Bandwidth Efficient methods for transmission of data have been and continue great importance to the data dependent community. A community that is experiencing exponential growth. Minimum ...

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MSK and its Application to Wireless Data Transmission continuous phase modulation (CPM) minimize BW consumption by eliminating phase discontinuities. CPM state changes are represented by non-abrupt changes in phase and frequency while the amplitude of the carrier envelope remains constant ...

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MSK and its Application to Wireless Data Transmission Rewriting equation (3) applying Euler’s equation for exponential relations, where, Here, m(t) is the modulating signal and constant of proportionality. Substituting (5) into (4) yields the equation for continuous ...

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MSK and its Application to Wireless Data Transmission Where < (n+1)T and is adjusted according to the phase of the previous symbol n modulating signal (NRZ binary data) has no impulses, the modulated carrier e(t) will not have ...

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MSK and its Application to Wireless Data Transmission Subtracting (17) from (16) yields, Equation (18) states, for h = 0.5 , the frequency separation between f a set of four waveforms for a typical MSK modulator. e(t) S =-1 n ...

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MSK and its Application to Wireless Data Transmission For any FSK system where = Performing the integration in (21) yields For MSK equation (18) can be rewritten in terms of radian frequency And the radian carrier frequency ...

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MSK and its Application to Wireless Data Transmission signal-to-noise ratio (SNR) versus BER. SNR is considered by some as an inaccurate method for comparison of performance because of its dependence on noise BW. In other words, the SNR can be ...

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MSK and its Application to Wireless Data Transmission Table 2: Tone frequencies for 1200/2400 bps MSK modem. The modulator generates tones that are phase continuous and change frequency at the zero crossings as shown in Figure 6. TX data 1200 ...

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MSK and its Application to Wireless Data Transmission signal frequency. This detection scheme is non-coherent because the receiver is neither phase nor time synchronized to the transmitter. MSK signal I/P The carrier detector output indicates if MSK signal is being ...

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MSK and its Application to Wireless Data Transmission TX SYNC Don’t care TX DATA RX SYNC Clocked Data The de-modulator provides the recovered clock and data in reference to this clock. The timing diagrams of the TX and RX sync ...

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MSK and its Application to Wireless Data Transmission 3. Modeling With increasing demand to move products quickly to market and to keep costs down, verifying a design through simulation before building a breadboard saves time and money. The rapid growth ...

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MSK and its Application to Wireless Data Transmission F(x) function F( ) evaluated with parameter x. For example: sin(x) is the sinusoidal function of trigonometry cos(x) is sin(x + /2) sinc(x) is sin(x)/x and has the value ...

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MSK and its Application to Wireless Data Transmission Pseudo-Code Listing 1 data rad data rad data rad data rad tx eye diagram 0 1/6 1/3 Figure 12: 1200 ...

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MSK and its Application to Wireless Data Transmission output sin p[i+1] = fractional remainder _____________________________________________________________________________________ 3.2 MSK Demodulation MSK Demodulation is the process of converting Sinusoids to digital data. MSK demodulation ...

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MSK and its Application to Wireless Data Transmission impulse responses for both baud rates are shown below in Figure 15 and Figure 16. These graphs show the magnitude responses of linear phase finite impulse response (FIR) filters. The filter weights ...

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MSK and its Application to Wireless Data Transmission Pseudo-Code Listing 2 ____________________________________________ I/O input[i] = current input sample output[i] = current output sample ____________________________________________ Pseudo Code if sign(input[i]) != sign(input[i-1]) output[ else output[ ________________________________________ 3.2.1.3 Monostable ...

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MSK and its Application to Wireless Data Transmission ___________________________________________ I/O, Variables, and Constants input[i] // Current input sample output[i] // Current output sample T = N/3 // 1/3 Bit time @ 1200 Baud N/2 // 1/2 Bit ...

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MSK and its Application to Wireless Data Transmission _____________________________________________________________________________________ I/O, Variables and Constants input[i] output[i] Taps[] = {0, N/6, N/3} = {0, N/2} state _____________________________________________________________________________________ Pseudo Code for Discriminator state = 1 for size of Taps-1 ...

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MSK and its Application to Wireless Data Transmission 3.2.1.5 Discriminator Low Pass Filter The discriminator low pass filter is designed to pass frequencies up to half the bit rate. This corresponds to the highest frequency needed to pass an NRZ ...

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MSK and its Application to Wireless Data Transmission 3.2.2.1 Bad Zero Crossing Detector The Bad Zero Crossing Detector monitors the zero crossings of the filtered input signal. The time between zero crossings is compared against a referenced. If the Bad ...

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MSK and its Application to Wireless Data Transmission Pseudo-Code Listing 5 Bad Zero Crossing Detector _____________________________________________________________________________________ I/O, Variables and Constants input[i] // current input sample output[i] // current output sample START // Array of valid-window START times {Nx0.2833} // 1200 ...

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MSK and its Application to Wireless Data Transmission _____________________________________________________________________________________ Pseudo-Code for Bad Zero Crossing Detector OK = TRUE; if (input[ FALSE; for j=0 to size of STOP and START arrays if ((counter >= START[i]) & ...

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MSK and its Application to Wireless Data Transmission 3.2.3.1 Digital Phase Lock Loop The PLL aligns the output clock rising edge to the middle of the input NRZ data bit. When the PLL is not aligned with the incoming data ...

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MSK and its Application to Wireless Data Transmission if reset is equal to 1 then { counter = 0; late = 0; early = 0; } else increment counter; _____________________________________________________________________________________ 3.2.3.2 Data Re-timing The date re-timing block aligns the data ...

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MSK and its Application to Wireless Data Transmission Carrier Det. Out Carrier Det. Filt. Out Carrier Det. Bad ZC Clocked Data Out Rx Sync. Clock Unclocked Data Out Discriminator Out Rx Filter Out Tx Bits Figure 31: System Simulation Signals ...

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MSK and its Application to Wireless Data Transmission Figure 33: RX Eye Diagram for 2400 Baud at 12dB SNR. 3.3.1 MSK Simulations with various SNR Figure 34 shows the simulated bit error rate performance of the system depicted in Figure ...

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MSK and its Application to Wireless Data Transmission The table below shows the required noise variance for SNR near 12dB with the system sampling rate equal baud rate. Effective SNR (dB Table 3: ...

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MSK and its Application to Wireless Data Transmission I/O, Variables and Constants input input sequence output output sequence IntIn = 0 // variable used to store integral of input[] sequence up to current time. step // ...

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MSK and its Application to Wireless Data Transmission _____________________________________________________________________________________ I/O, VARIABLES and CONSTANTS RFinput[ input IFoutput[ output // local oscillator frequency normalized to sampling rate of block note f is offset from ...

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MSK and its Application to Wireless Data Transmission while j<L { sum = sum + (input[i-j] x weights[j]); increment j; } output[i] = sum; _____________________________________________________________________________________ Pseudo-Code Listing 11 Comparator with Hysterisis _____________________________________________________________________________________ I/O, VARIABLES and CONSTANTS input[i] ...

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MSK and its Application to Wireless Data Transmission 3.5 References [1] J.B. Anderson, T. Aulin and Carl-Erik Sundberg, Digital Phase Modulation , Plenum Press, New York, NY, 1986. [ Crochiere and L. R. Rabiner, Multirate Digital Signal Processing ...