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bamse
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Hello,
I have to design a digital communication-system based on IEEE 802.15.4
(zigbee) in Simulink.
In the following, I will use matlab-syntax.
message='hello'; % source-data
bit=8; % bit-resolution
message_dec=double(message); %convert source-data into ASCII
message_bin=dec2bin(message_dec,bit); %convert ASCII to binary
message_bitstream = reshape(message_bin',1,size(message,2)*bit); % shape
into bitstream
The next procedure is to do the following:
1) Bit to symbol mapping
2) Symbol to chip mapping
3) Offset-QPSK modulation
Regarding 1:
The 4 least significant bits of an octet are mapped into one data-symbol
The 4 most significant bits of an octet are mapped into one data-symbol.
Therefore, there are 16 possible data-symbols
Regarding 2:
Each data-symbol is mapped into a 32 bit PN-sequence (chip-symbol)
Regarding 3:
The PN-sequence is modulated onto a carrier using offset-QPSK.
Can anyone tell me how I do this in Matlab/simulink because I am
totally lost. I have been looking at the OQPSK-block in simulink
but I dont know how to use it correctly. So I thought it would be
easier to make a matlab-file instead.
Any help will be appreciated.
Thanks
)
For the interested reader the specification can be found here:
http://kom.aau.dk/~jash02/ieee802-15-4.pdf
I have to design a digital communication-system based on IEEE 802.15.4
(zigbee) in Simulink.
In the following, I will use matlab-syntax.
message='hello'; % source-data
bit=8; % bit-resolution
message_dec=double(message); %convert source-data into ASCII
message_bin=dec2bin(message_dec,bit); %convert ASCII to binary
message_bitstream = reshape(message_bin',1,size(message,2)*bit); % shape
into bitstream
The next procedure is to do the following:
1) Bit to symbol mapping
2) Symbol to chip mapping
3) Offset-QPSK modulation
Regarding 1:
The 4 least significant bits of an octet are mapped into one data-symbol
The 4 most significant bits of an octet are mapped into one data-symbol.
Therefore, there are 16 possible data-symbols
Regarding 2:
Each data-symbol is mapped into a 32 bit PN-sequence (chip-symbol)
Regarding 3:
The PN-sequence is modulated onto a carrier using offset-QPSK.
Can anyone tell me how I do this in Matlab/simulink because I am
totally lost. I have been looking at the OQPSK-block in simulink
but I dont know how to use it correctly. So I thought it would be
easier to make a matlab-file instead.
Any help will be appreciated.
Thanks
)For the interested reader the specification can be found here:
http://kom.aau.dk/~jash02/ieee802-15-4.pdf