Ultrasonic human body communication method based on a group index modulation, and a device thereof

Patent metadata

Field	Value
Publication number	US-11838063-B2
Application number	US-201917772519-A
Country	US
Kind code	B2
Filing date	Dec 18, 2019
Priority date	Oct 29, 2019
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

Provided are an ultrasonic human body communication method and a device thereof, the method including dividing serial information into blocks, and each information block includes modulation bits and index bits; each transmission frame is divided into multiple groups; performing an index modulation on the groups of each transmission frame, determining activated group sequence numbers; performing a digital modulation on the modulation bits of each information block, and mapping the digitally modulated modulation bits to activated groups; for the multiple information blocks processed in parallel, performing a parallel/serial conversion, a pulse shaping, and an ultrasonic conversion in sequence to obtain a transmission signal, and transmitting the transmission signal in a human body through a transmission frame; on a receiving node, receiving a received transmission signal propagated by the human body, and demodulating the received transmission signal to obtain the index bits and the modulation bits.

First claim

The invention claimed is:

1. An ultrasonic human body communication method based on a group index modulation, wherein the method comprises the following steps:
S 1 . on a transmission node, performing a serial-to-parallel conversion on serial information, and dividing into multiple information blocks, wherein each information block comprises Y modulation bits and M index bits;
S 2 . for each transmission frame, dividing the transmission frame into multiple groups;
S 3 . performing an index modulation on the groups of each transmission frame, and determining activated group sequence numbers corresponding to the groups according to the index bits of each information block;
for each information block, performing a digital modulation on the modulation bits of the information block, and mapping the digitally modulated modulation bits to activated groups corresponding to the activated group sequence numbers;
S 4 . for the multiple information blocks processed in parallel in step S 3 , performing a parallel-to-serial conversion, a pulse shaping, and an ultrasonic conversion in sequence to obtain a transmission signal s(t), and transmitting the transmission signal s(t) in a human body through the transmission frame; and
S 5 . on a receiving node, receiving a received transmission signal s′(t) propagated by the human body, demodulating the received transmission signal s′(t), and obtaining the index bits and the modulation bits.

2. The ultrasonic human body communication method based on a group index modulation according to claim 1 , wherein the transmission node and the receiving node are both located in a wireless communication network using the human body as a transmission medium, wherein:
in step S 2 , according to a number of access nodes, time slots for sending the transmission frames are divided into N groups, a number of time slots in each group is not less than the number of access nodes, assigning each access node a single time slot in a group; and
an access node is the transmission node that is used to send information blocks in the wireless communication network.

3. The ultrasonic human body communication method based on a group index modulation according to claim 2 , wherein in step S 3 , the digitally modulated modulation bits are mapped to transmission time slots in the activated groups corresponding to the activated group sequence numbers, wherein the transmission time slots are determined by transmission nodes, and wherein different transmission nodes use different time slots as the transmission time slots that carry the modulation bits.

4. The ultrasonic human body communication method based on a group index modulation according to claim 2 , wherein performing the index modulation on the groups of each transmission frame, and determining activated group sequence numbers corresponding to the groups according to the index bits of each information block, are specifically:
activating K groups of the N groups, the activated K groups are the activated groups, and combination types of the activated K groups are C N K types;
obtaining different activated group sequence numbers corresponding to different activated group combinations;
determining the corresponding activated group sequence numbers according to the index bits of each information block, to obtain the corresponding activated group combinations;
a relationship between the number M of index bits and the combination types of the activated groups C N K is:
M =└log 2 ( C N K )┘;

wherein └·┘ is a floor function; and
a relationship between the number Y of modulation bits and the number K of activated groups is:
Y=K log 2 R;

wherein the relationship indicates that each group of the K activated groups transmits log 2 R bits, wherein R is an order of the digital modulation, R is 2 x , and x is a positive integer.

5. The ultrasonic human body communication method based on a group index modulation according to claim 1 , wherein the digital modulation is a pulse phase modulation, a pulse position modulation, a pulse amplitude modulation, a pulse width modulation or a pulse waveform modulation.

6. The ultrasonic human body communication method based on a group index modulation according to claim 5 , wherein the transmission signal s(t) is an ultrasonic pulse signal;
when the digital modulation is the pulse amplitude modulation, the transmission signal s(t) is as follows:

s
⁡
(
t
)

=

∑

j
=
1

∞

∑

k
=
1

K

a

j
,
k

⁢

p
⁡
(

t
-

jT
s

-

P

j
,
k

⁢

T
g

-

c
j

⁢

T
c

)

;

wherein t is time, j is a sequence number of the transmission frame; k is a sequence number of activated groups; p(t) is a mono-cycle pulse signal, a pulse width of p(t) is less than a width of a time slot; T s is a time length of the transmission frame; T g is a time length of a group; T c is a time length of a time slot; P j,k is the kth activated group in the jth frame; c j is the time slot sequence number in the groups of the jth transmission frame; a j,k is the modulation bits transmitted in the c j th time slot of the kth activated group in the jth transmission frame.

7. The ultrasonic human body communication method based on a group index modulation according to claim 1 , wherein using a maximum likelihood method to demodulate the received transmission signal s′(t) to obtain index bits and modulation bits, processes are performed as follows:
S 51 . performing correlation calculations on the received transmission signal s′(t) and multiple template signals m l (t) respec

Assignees

• Univ South China Tech

Inventors

• Guan Quansheng
• Wang Qianqian

Classifications

• H04B13/005 Primary

  Transmission systems in which the medium consists of the human body · CPC title

• H04B11/00

  Transmission systems employing ultrasonic, sonic or infrasonic waves · CPC title

• H04L5/0003

  Two-dimensional division · CPC title

• H04L25/03834

  using pulse shaping · CPC title

• H04B14/02 Primary

  characterised by the use of pulse modulation (in radio transmission relays H04B7/17) · CPC title