Method and system for cross-technology communication from WiFi device to ZigBee device

1. A method for cross-technology communication from a WiFi device to a ZigBee device, comprising steps of:

generating, by a WiFi transmitter, to-be-transmitted symbol-level energy modulation bits information simultaneously carrying WiFi data bits and cross-technology data bits transmitted to the ZigBee device, wherein the cross-technology data bits are obtained based on symbol-level energy modulation; and

processing, by a ZigBee receiver, received signal strength indication sample information and initiating a cross-technology communication receiving process to obtain the cross-technology data bits needing to be received, and

obtaining, by a WiFi receiver, the to-be-transmitted symbol-level energy modulation bits information through a standard WiFi receiving process, and then initiating a WiFi data recovery process to obtain original WiFi data bits.

2. The method according to claim 1 , wherein when the WiFi transmitter simultaneously transmits the cross-technology data bits and the WiFi data bits, two constellation points having a same phase and different amplitudes carry same WiFi data bits information and different cross-technology data bits information.

3. The method according to claim 1 , wherein the to-be-transmitted symbol-level energy modulation bits information is obtained by:

modulating the WiFi data bits to convert the WiFi data bits from serial bits to parallel constellation points, wherein quadrature phase shift keying is adopted for modulation when a subcarrier is configured to transmit cross-technology information;

remapping a quadrature phase shift keying constellation point onto a quadrature amplitude modulation constellation point; and

performing parallel-to-serial conversion and quadrature amplitude modulation demodulation on all parallel quadrature amplitude modulation constellation points to obtain the to-be-transmitted symbol-level energy modulation bits information.

4. The method according to claim 3 , wherein the step of remapping the quadrature phase shift keying constellation point onto the quadrature amplitude modulation constellation point comprises steps of:

establishing a mapping relationship between the quadrature phase shift keying constellation point and the quadrature amplitude modulation constellation point according to an energy requirement of orthogonal frequency division multiplexing symbol, wherein the energy requirement of the orthogonal frequency division multiplexing OFDM symbol is related to the to-be-transmitted cross-technology data bits and cross-technology symbol transmission time.

5. The method according to claim 1 , wherein the ZigBee receiver obtains the cross-technology data bits needing to be received by:

selecting, from a sample set {r i } of the received signal strength indication sample information, a candidate sample set {{circumflex over (r)} i k }, wherein k represents an index of the candidate sample set, and i represents an index of a sampling point;

selecting an optimal sample set from the candidate sample sets, wherein the optimal sample set has a largest cumulative received signal strength indication distance compared with other candidate sample sets; and

obtaining the cross-technology data bits through energy demodulation.

6. The method according to claim 5 , wherein the optimal sample set is obtained by:

calculating a mean value of the sample set {r i } of the received signal strength indication sample information, the mean value being expressed as m r =mean({r i }); and

calculating a cumulative received signal strength indication distance between each of the candidate sample sets {{circumflex over (r)} i k } and the m r , the cumulative received signal strength indication distance being expressed as

d

RSSI

k

=

∑

i

=

1

N

⁢



r

^

i

k

-

m

r



,

the candidate sample set having the largest cumulative received signal strength indication distance d RSSI k being considered as the optimal sample set { r i }, wherein i∈[1,N], and the N represents the number of samples of the received signal strength indication sample information in the {r i }.

7. The method according to claim 6 , wherein the energy demodulation is carried out by:

a corresponding bit being ‘1’ in response to a value r i of the optimal sample set { r i } being greater than a threshold β, and the corresponding bit being ‘0’ in response to the value r i of the optimal sample set { r i } being equal to or less than the threshold β, wherein the β represents the mean value m r of the sample set {r i } of the received signal strength indication sample information.

8. A system for cross-technology communication from a WiFi device to a ZigBee device, comprising a WiFi transmitter, a ZigBee receiver, and a WiFi receiver, wherein the WiFi transmitter generates to-be-transmitted symbol-level energy modulation bits information simultaneously carrying WiFi data bits and cross-technology data bits transmitted to the ZigBee device, and the cross-technology data bits are obtained based on symbol-level energy modulation; and the ZigBee receiver processes received signal strength indication sample information and initiates a cross-technology communication receiving process to obtain the cross-technology data bits needing to be received, and the WiFi receiver obtains the to-be-transmitted symbol-level energy modulation bits information through a standard WiFi receiving process, and then initiates a WiFi data recovery process to obtain original WiFi data bits.