BCC communication through RZ Bipolar D-QPSK Encoding and Decoding with Hybrid RF base and FPGA Implementation

Abstract

As of now it is seen that many technological developments are happening in the world particularly in the bio-medical field. These developments are helping the human being for easier diagnosing, identification, altering and rectifying the diseases immediately. With this advancement of communications such us Body Channel Communication (BCC), the problem solving can be carried out by the doctors at the real time in spite of long distance between doctors and patients. The transmitting and receiving the data such as blood pressure, temperature, ECG and EMG etc., can be made without any error in the signal. By the conventional BCC mode of communication it is experienced that there is several unwanted signals such as jitter noise, distortion in signals due to different body postures and motions of human and also it affects the human freedom. In order to overcome all these difficulties, DQPSK modulation technique is proposed and utilized in this research and to achieve high speed data transfer with more accuracy. In this research, to effect long range BCC, body wearable devices to monitor blood pressure, temperature, ECG and EMG are used. The output signals from these sensors are transmitted through 4, 8, 16 DQPSK modulators. For the purpose of secured and reliable data, 16 DQPSK techniques are used to achieve proper encoding and decoding methods. Hence, the line coding method is implemented in this proposed work to achieve the resultant data will be of error free without any overlap of signals. In this novel line coding method, RZ-Bipolar procedure is used to get greater data communication even with less power consumption and less bandwidth. To end with this VHDL design work, it is synthesized using MAX10 Altera Quaratus FPGA to study the performance comparison of output parameters such as power, delay and area. Index Terms-DQPSK (Differential Quadrature phase shift keying), ECG (Electrocardiogram), EMG (Electromyogram), NRIZ (Non return to zero inverted), RZ(Return zero).

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International Journal of Advanced Science and Technology
Vol. 29, No. 7s, (2020), pp. 686-694
686
ISSN: 2005-4238 IJAST
Copyright ⓒ 2020 SERSC
BCC communication through RZ Bipolar D-QPSK Encoding and Decoding
with Hybrid RF base and FPGA Implementation
1Dr. S.Vijayalakshmi, 2Mr. Sakthivel Sankaran, 3Dr. M. Pallikonda Rajasekaran, 4Dr.
V.Nagarajan and 5Dr. E.Sankaran
1,2,5Assistant Professor and 3,4Professor
1,3,4Department of Electronics and Communication Engineering,
2Department of Biomedical Engineering
5Department of Electrical and Electronics Engineering
1Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, Chennai,
TN, India
2,3Kalasalingam Academy of Research and Education, Krishnankoil, TN, India
4Adhiparasakthi Engineering College, Melmaruvathur, TN, India
5GRT Institute of Engineering and Technology, Tiruttani, TN, India
1sankarviji7@gmail.com, 2sakthivelsankaran92@gmail.com, 3mpraja80@gmail.com,
4nagarajanece31@gmail.com and 5esankaran@gmail.com
Abstract
As of now it is seen that many technological developments are happening in the world particularly
in the bio-medical field. These developments are helping the human being for easier diagnosing,
identification, altering and rectifying the diseases immediately. With this advancement of
communications such us Body Channel Communication (BCC), the problem solving can be carried
out by the doctors at the real time in spite of long distance between doctors and patients. The
transmitting and receiving the data such as blood pressure, temperature, ECG and EMG etc., can be
made without any error in the signal. By the conventional BCC mode of communication it is
experienced that there is several unwanted signals such as jitter noise, distortion in signals due to
different body postures and motions of human and also it affects the human freedom. In order to
overcome all these difficulties, DQPSK modulation technique is proposed and utilized in this research
and to achieve high speed data transfer with more accuracy. In this research, to effect long range
BCC, body wearable devices to monitor blood pressure, temperature, ECG and EMG are used. The
output signals from these sensors are transmitted through 4, 8, 16 DQPSK modulators. For the
purpose of secured and reliable data, 16 DQPSK techniques are used to achieve proper encoding and
decoding methods. Hence, the line coding method is implemented in this proposed work to achieve the
resultant data will be of error free without any overlap of signals. In this novel line coding method,
RZ-Bipolar procedure is used to get greater data communication even with less power consumption
and less bandwidth. To end with this VHDL design work, it is synthesized using MAX10 Altera
Quaratus FPGA to study the performance comparison of output parameters such as power, delay and
area.
Index Terms—DQPSK (Differential Quadrature phase shift keying), ECG (Electrocardiogram),
EMG (Electromyogram), NRIZ (Non return to zero inverted), RZ(Return zero).
I. Introduction
As it is seen that, now a days there is a rapid change and development of technologies in
the fields of wireless communication, internet and telecommunication etc,. The biomedical
engineering field is also one of the major areas which also developed significantly. While
comparing to other types of communications, the body wearable devices based body channel
communication (BCC) is rendering the major benefits such as low power consumption,
reduced chip area, reduced signal noise and high speed data transfer etc. The real time

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monitoring and diagnosing the health issues of patients is possible by using of body wearable
devices and RF based BCC. The various testing schemes such as Temperature, Blood
pressure, EMG, ECG and so on are sensed and transmitted by body wearable devices. Hence
the health conditions of patients can be diagnosed preciously, in both internal and external
conditions of patients. Moreover, the critical illness such us wheezing, fewer, seizure
prediction, heart attacks and so on are also accurately diagnosed and taken care for treatment.
In the case of children, illiterate and disabled persons who they are not capable to express
their sickness, these types of body wearable devices will be very much useful to sense the
various body parameters. It is also possible to easily locate the preliminary stages of several
diseases such as heart attacks, high rates of fewer. By identifying the disease and its root
cause in the beginning stage itself, the patient can be treated and the growth of the sickness
can be controlled within short time. Thereby the patient can be recovered from the diseases
soon.
The communication systems such as WI-FI, Bluetooth, Zigbee and RF are used to transmit
the signals from the body wearable devices used in the patient’s health monitoring system. In
order to achieve secured data transmission, in this research the RF based communication is
established for long range data transmission. The long range of communication and higher
bandwidth are supported by the wireless based communication. Due to this advantage, we
can achieve less bandwidth as well as high throughput by using DQPSK. With reference to
other types of communications such as BPSK and BFSK, DQPSK provides better
performance. While consuming the same amount of power and delivering the same
throughput, the Differential Quadrature phase shift keying plays a predominant role. Also the
circuit complexity can be minimized and the unwanted carrier recovery loop can be
eliminated in the demodulator section. The carry recovery loop can be separated and by
means of transmitting and receiving the signals differentially using DQPSK modulation. Also
in the demodulator, the same carrier frequency can be maintained. Moreover, 2.3dB along
with higher level SNR is only needed.
II. Literature Survey
Chien-Chuan Hung, will discuss elaborate a method of DQPSK modulation and
Demodulation for wireless network on chip based communication with compared
BPSK, BFSK based modulation, this work will developed 65nm CMOS technology
with VHDL synthesized in Vertex-7 FPGA, the priority based focus of this work is
Network on Chip with emerged in multi band of RF communication and will reduced
the latency, energy dissipation, metal/dielectric, wired link with high bandwidth.
Kalyana Sundaram, Marichamy, 2016 ICONSTEM, discussed about this FPGA based
Filters for EEG Pre-Processing. In this work to filtering the signal of ECG and EMG
using Proposed Median Filtering, and its implemented with Vertex-5 FPGA, will
shown the good comparison results of area, power and delay. This Median filter
occupies small area, and its moving average fast and best preprocessing one.
Dilranjan S. Wickramasuriya, Lakshitha P.Wijesinghe and Sudaraka
Mallawaarachchi, discussed about the reliable forecasting by utilizing FPGA with
Hilbert Huang Transform. In this work will present to find the Seizure prediction
using EEG signal with recording intracranial EEG signals to continuous monitoring a
Body Area Network and its predicting epileptic seizures using scalp EEG. This paper
will implemented in FPGA and also got Less Area, Delay and Power.

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Valentijn De Smedt, Graduate Student Member, IEEE, Georges Gielen, this persons
will describe for Development of an Ultralow power injection locked PSK Receiver
Architecture, this technology of proposed PSK receiver will using injection locked
oscillator with wireless sensor networks, which is mainly focused on low power
application and data modulation, a novel D filp flop will detect the clock signals for
phase step and reduced the power consumption, this paper will implement in CMOS
technology.
III. Proposed Work
In this research work, it is proposed to use RF based wearable devices with BCC. This
type of communication will not affect human health. Also, it will reduce the distortion due to
noises in the signal, if any. The RF based communication is faster to access with the range of
902MHz to 906 MHZ as uplink and downlink respectively when compare to Human based
BCC. The additional parameters namely temperature, pressure are also sensed in addition to
ECG and EMG etc., This proposed work is ensured to achieve the reliable encrypting and
decrypting data parameters by utilizing effective communication and novel line coding
method in the secure BCC module. The area and power is reduced by using the simple
proposed architecture. Also, the time period of transmission and reception can be used
reduced by varying the data bit rate of the device. The transmission time can be reduced even
in the dense signal area, when the device is used with RF based communication.
i) RZ Bipolar Encoding and Decoding:
The line coding method is consists of both the futures of encoding as well as decoding.
Though there are several types of methods, here in this research RZ-Bipolar is considered.
Fig. 1. Waveform diagram of RZ-Bipolar
In Fig. 1 RZ-Bipolar waveform will have three inputs and one outputs such as clock, Data
and Bipolar outputs (NRZ, RZ), this technique will applied for three voltages namely +,- and

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0. In this diagram the voltage level will transition from + to -, from - to +, from + to 0, from -
to 0, based upon this the two method of NRZ (Non Return Zero) and RZ (Return Zero) output
will plotted.
ii) Non Return Zero method:
In the method of Non Return Zero the encoding output will plotted as per the rising edge
of the clock signal its changes based upon flip flop method, the input data to be '1' in first
clock cycle, the output of Bipolar-NRZ will give '1' and its after change only on second rising
edge, in this second rising edge it will read the input data '0' and the output stabled in '0', third
rising edge the data on '1' the output will goes to '0', regarding this every changes, the output
will change '0' to '-1', '-1' to '0', '0' to '1' and '1' to '0', as per this the truth table will shown
below in Table I.
Table I
Truth table of Bipolar NRZ
Clock
Data
Bipolar NRZ
1st Rising Edge
1
1
2nd Rising Edge
0
0
3rd Rising Edge
1
-1
4th Rising Edge
0
0
5th Rising Edge
0
0
6th Rising Edge
1
1
7th Rising Edge
1
-1
8th Rising Edge
1
1
9th Rising Edge
0
0
iii) Return Zero method:
In the method of Return Zero the encoding output will plotted as per the rising level of the
clock signal its changes based upon latches method, the input data to be '1' in first clock
cycle, the output of Bipolar-RZ will give '1' and its after change only on falling level, in this
second rising level it will read the input data '0' and the output stabled in '0', third rising level
the data on '1' the output will goes to '0', regarding this every changes, the output will change
'0' to '-1', '-1' to '0', '0' to '1' and '1' to '0', as per this the truth table as Table II.
Table II
Truth table of Bipolar-RZ
Clock
Data
Bipolar NRZ
1st Rising level
1
1
1st Falling level
1
0
2nd Rising level
0
0
2nd Falling level
0
0
3rd Rising level
1
-1
3rd Falling level
1
0
4th Rising level
0
0
4th Falling level
0
0
5th Rising level
0
0
5th Falling level
0
0
6th Rising level
1
1
6th Falling level
1
0

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7th Rising level
1
-1
7th Falling level
1
0
8th Rising level
1
1
8th Falling level
1
0
9th Rising level
0
0
9th Falling level
0
0
In the proposed architecture of RZ Encoding and Decoding method shown in Fig. 2 and
Fig. 3 respectively will used for Wearable device of body channel communication, regarding
this method will support level triggering based encoded the data, this is having a tight
security control over the congestion of signals, from '-1' to '0', '0' to '-1', '1' to '0' and '0' to '1'.
Here for the purpose of decoding a clock signal in the order of x2 clock is used for reading
the data. This data is stored in the memory and further it is processed in a decoder.
Advantages:
This architecture design is simple to construct.
A single error detection capability is provided.
Fig. 2. Encoding architecture of Bipolar NRZ/RZ
Fig. 3. Decoding architecture of Bipolar NRZ/RZ
ECG
EMG
Temperature
Pressure
2-Channel
ADC
Bipolar RZ
Encoding
D-QPSK
Modulatio
n
GPIO
RF
Transmitter
DAC
Interface
UART-TX
ECG
EMG
Temperature
Pressure
DAC
Interface
Bipolar
RZ
Decoding
D-QPSK
De-
Modulati
on
GPIO
RF
Receiver
PQRST
Delineation
PAT
Algorithm
ECG
Filtering
Feature
Extraction
and
Classificatio
n
Record Data
UART

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No low-frequency component is present.
Occupies low bandwidth than Uni-polar and polar NRZ schemes.
IV. Results and Discussion
The schematic diagram is shown in Fig. 4 is used to describe the RF based FPGA
Implementation of BCC Wearable device with RZ Bipolar Encoding and Decoding using D-
QPSK modulation and Demodulation. The major blocks are RZ_Bipolar DQPSK modulator
and demodulator. The ecg_data[7:0] shall not be transmitted for a long distance directly. The
signal strength should be increased by means of a higher frequency carrier_signal[7:0]. The
specifications/values of ecg_data will not get affected by using the carrier wave.
Fig. 4. RTL Schematic of RZ_Bipolar DQPSK Modulation and Demodulation
The reliable communication establishment is done through higher frequency carrier signal
is done by modulator. In order to enable the modulator, the various clock signals such as
clkd, clkm and clks are used with the reset signal and start. The extraction of the original
ecg_data from the modulator carrier wave is achieved by demodulator. As same like
modulator, the demodulator also opposed with the various clock signals such as clkd, clkm
and clks are used with the reset signal and start. The Register Transfer Level RTL schematic
is implemented by using DQPSK modulation and Demodulation to achieve better results.
The Model Sim is implemented with the work routine of the DQPSK modulator and
demodulator is shown in Fig. 5 and Fig. 6 respectively. This VHDL design is applied and it is
combined by using FPGA model MAX10 Altera Quaratus. The number of repetitions is a
significant examination while coding and decoding. While the cycles of repetitions are
increased, the error rate is getting reduced and thereby a better performance is achieved.

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Fig. 5. Waveform of RZ_Bipolar DQPSK Modulation
Fig. 6. Waveform of RZ_Bipolar DQPSK Demodulation
Table III
Comparison Of Differenct Bits Of DQPSK RZ Unipolar
4-DQPSK RZ
Bipolar
8-DQPSK RZ
Bipolar
16-DQPSK RZ
Bipolar
Total logic elements
1048
1048
1048
Total registers
611
611
611
Total pins
31
31
31
Total memory bits
90
90
90
Power Dissipation
1.37mW
1.38mW
1.3mW
Delay
2000ps
2000ps
2000ps
VHDL is used to implement the DQPSK modem scheme. The VHDL scheme is simulated
by using the simulation tool. The output of the pulse shaping filter is compared and verified
with the SIMULINK pulse shaping filter model output.

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The Table III indicates the comparison of 4, 8 and 16-DQPSK modulation techniques. It is
obvious that the 16-DQPSK modulation techniques yielded the power dissipation as 1.3mW
which is lowest among the all techniques. Also, the various parameters such as number of
logic elements, number of registers, number of pins and number of memory bits are
compared among all techniques.
Table IV
PERFORMANCE COMPARISON
Parameters
Namjun Cho ref. [7]
Wala Saadeh ref. [15]
This Work
Technology
0.18 μm
65nm
65nm
Modulation
AFH-FSK
FSK
16-DQPSK
Supply Voltage
1 V
1 V
1.1 V
Data Rate
10Mb/s
1Mb/s
60Mb/s
Area
2.30 mm2
2.13mm2
1.64mm2
Power
3.7mW
1.4mW
1.3mW
The existing work and the proposed work performances are compared and tabulated in
Table IV. By up keeping the data transfer rate at 60Mb/s, the area is reduced to 1.64mm2. The
total power consumption of this work including modulator and demodulator is found to be at
1.3mW. Also the DQPSK modulator design is matched to the estimated design time period.
V. Conclusion
In this research paper, the human body is considered as a good transmission channel as per
the Body Channel Communication (BCC). This BCC does not require any wiring or
antennas. A reliable and distortion less communication is inevitable to achieve the actual
ECG data in spite of different frequencies, different provinces, dissimilar body conditions and
postures. The RF based BCC Wearable device with RZ Bipolar Encoding and Decoding
using D-QPSK is implemented in FPGA and the parameters such as area, power are analyzed
and achieved the power savings in the order of 1.3mW while the area is 1.64mm2only.
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