PSK2K is a meteor scatter type of mode
written by DJ5HG
Using a modulation scheme of
Phas Shift Keying at 2000 bits per second also The pulse shape is a sinc-function. The result is a minimum-energy modulation, not a constant-amplitude modulation
Bandwidth : As a consequence of the sinc-pulse, the spectrum of the transmitted signal has a rectangular shape
of 2000 Hz width
Every code word of PSK2k has 258 bits. Since the Baudrate is 2000 bits/s a code word is transmitted in 129 ms. Identical code words are transmitted continuously.
Every sixth bit of a code word (bits 1, 7, 13, 19, ... , 247, 253) belongs to a synchronization pattern The synchronization pattern is a Hadamard code of 43 bits:
0100101001110111110001011100000100011010110.
Another part of the packet is the binary address. There are two types of addresses: The general address used for all transmissions addressed to everybody, i.e. CQ calls, QRZ calls,
and QSTs. The general address has the binary pattern
1101010000001111100110011011011011011011011011011.The private address is used to address a target callsign. It is unique for every callsign. The address for DJ5HG for example is
0000111101011001010101101010011100100011101010101.
The encoding of the private address is specified in the PSK2k documentation (7.1. and 7.2). If the synchronization records a hit then the two addresses are correlated with the corresponding bits of the packet and the best fitting address is taken. Then the carrier phase is detected from the bits of the synchronization pattern and the bits of the address, and the phase then is interpolated to the remaining data bits of the code word. This yields 166 soft bits for the decoding process.
In all cases three nested codes are used. The outer convolutional code (the channel code) is for error correction. The inner code is for detection of remaining errors. It is mainly this code that prevents from display of garbage. The third code is the source code which translates the bit arrays into displayed text output. There is a plausibility check at this stage which refuses the display of callsigns that do not comply with the syntax of callsigns. There are several coding schemes for different message types:
+Advantges of PSK2K is it is a fairly senstive mode
+you can have different intervals of calling and returning times
+and a automated QSO sequence option
- Not many people know about it
written by DJ5HG
Using a modulation scheme of
Phas Shift Keying at 2000 bits per second also The pulse shape is a sinc-function. The result is a minimum-energy modulation, not a constant-amplitude modulation
Bandwidth : As a consequence of the sinc-pulse, the spectrum of the transmitted signal has a rectangular shape
of 2000 Hz width
Every code word of PSK2k has 258 bits. Since the Baudrate is 2000 bits/s a code word is transmitted in 129 ms. Identical code words are transmitted continuously.
Every sixth bit of a code word (bits 1, 7, 13, 19, ... , 247, 253) belongs to a synchronization pattern The synchronization pattern is a Hadamard code of 43 bits:
0100101001110111110001011100000100011010110.
Another part of the packet is the binary address. There are two types of addresses: The general address used for all transmissions addressed to everybody, i.e. CQ calls, QRZ calls,
and QSTs. The general address has the binary pattern
1101010000001111100110011011011011011011011011011.The private address is used to address a target callsign. It is unique for every callsign. The address for DJ5HG for example is
0000111101011001010101101010011100100011101010101.
The encoding of the private address is specified in the PSK2k documentation (7.1. and 7.2). If the synchronization records a hit then the two addresses are correlated with the corresponding bits of the packet and the best fitting address is taken. Then the carrier phase is detected from the bits of the synchronization pattern and the bits of the address, and the phase then is interpolated to the remaining data bits of the code word. This yields 166 soft bits for the decoding process.
In all cases three nested codes are used. The outer convolutional code (the channel code) is for error correction. The inner code is for detection of remaining errors. It is mainly this code that prevents from display of garbage. The third code is the source code which translates the bit arrays into displayed text output. There is a plausibility check at this stage which refuses the display of callsigns that do not comply with the syntax of callsigns. There are several coding schemes for different message types:
+Advantges of PSK2K is it is a fairly senstive mode
+you can have different intervals of calling and returning times
+and a automated QSO sequence option
- Not many people know about it
Mode Menu
PSK2K
Mode Audio Sample
FFT Window Screenshot
