Method for transmitting signals in multi-carrier radio transmission system

A method for forming pilot signals in a multi-carrier radio transmission system, wherein a transmission block is composed of N consecutive OFDM symbols in a time domain and M consecutive physical sub-carriers in a frequency domain, where N is an integer and not less than 1, and M is an integer and not less than 1, comprising following steps:

• 1) a time-frequency cell grid, (n,an,bn,cn) such as (1,1,1,1), is selected in the transmission block, where n=1 and time=0;
• 2) The value of time increments by 1 and n increments by 1;
• 3) ‘an’ takes a value of 1+L−a(n−1), where L is twice an integer and the integer is not more than N/4;
• bn=b(n−1);
• If a1=1, cn=c1;
• and if a1=2, cn=2 or 1;
• 4) judge whether time=L/2;
• If so, the process turns to step 7;
• and if not, the process turns to step 5;
• 5) n increments by 1;
• 6) ‘an’ takes a value of ((1+a(n−2))mod(L+1))+1;
• bn=3−b(n−2);
• and cn=c(n−1);
• then the process turns to step 2;
• 7) judge whether N is an integer multiple of 4;
• if so, the process turns to step 10;
• otherwise, the process turns to step 8;
• 8) n increments by 1;
• 9) ‘an’ takes the value of the last group of OFDM symbols that have not been allocated;
• bn=1 or 2;
• if a1=1 and c1=1, cn=1 or 2;
• and if a1 and c1 are not both 1, cn=2 or 1.