Methods and apparatus for balancing multi-symbol modulation schemes in
cellular communications are provided. The modulation schemes include a
plurality of modulation symbols, each of which codes a predefined bit
group, which includes one or more bits. The bit groups define different
bit positions for bits within the bit groups. The bit positions of the
modulation symbols are associated with different error probability
levels. Each error probability level defines a probability level of an
erroneous bit value at a defined bit position in the bit group, which is
obtained by a mapping operation from the modulation symbol transmitted
over a radio frequency channel with noise. Binary content to be modulated
is provided in form of code blocks I (where i=1 to n). Each of the code
blocks is carried on a corresponding code channel i. The code blocks on
the code channels are supplied to the modulation schemes in that each
code channel is associated with one predefined bit position of the bit
groups to enable a mapping to modulation symbols. The bit groups are
formed from the binary content of the code blocks in accordance with the
code channel-to-bit position association defined above. The binary
content of at least two code blocks is shuffled, distributed, or
scattered in accordance with predetermined shuffling, distributing, or
scattering rules. The shuffling, distributing, or scattering aims to
achieve substantially balanced or same error probability levels for said
code channels. The shuffling operation should be performed to achieve a
substantially evenly distribution of the binary content upon the involved
code blocks.