Feedback Overhead in the FDD Downlink Massive MIMO System

Algorithm 3

AC feedback overhead encoding.

1: Input: : sequence to compress; : the symbol probabilities are known.

2: Output Val: a binary number that represents sequence .

3: (Cum = cumulative probability and coincides with the various terminals: );

4: for {} do

5:      is the number of symbols in the alphabet (the number of intervals)

6: low = ; high=       the lower and upper bound; the number of bits

7: First_qtr=; half= ; Third_qtr= ;

8: bits_To_follow:= ;  Number of bits to look at in order to know which part we are on

9 fordo

10:  

11:  

12:  

13:  while 1 do

14:    if                    the lower part

15:    transmission of bit “0”; ;

16:    low =2 low; high =2 high;

17:    else if                  the high part

18:    transmission of bit “1”; ;

19:    low = low-Half; high = high-Half;

20:    low =2 low; high =2 high;

21:    else if      n the middle

22:    bits_To_follow =bits_To_follow + 1;

23:    low = low-First_qtr; high = high-First_qtr;

24:    low =2 low; high =2 high;

25:    else

26:    break;

27:    End if;

  After that we encode the symbol EOF_symbol as before to allow the decoder to stop.

28:return   bin2dec converts the binary vector to a decimal number

   =0