Channel estimation for FBMC modulation

A method implemented in a second node of a communication system employing filter bank multi-carrier (FBMC) modulation with a real symmetric pulse, comprising:

• demodulating symbols in a predetermined pilot field in a FBMC-modulated signal received from a first node;
• and
• performing channel estimation on the basis of the demodulated symbols and of predetermined pilot symbols, wherein the pilot field is populated with two symbols, which are either consecutive in frequency and coinciding in time or coinciding in frequency and consecutive in time, and wherein at least two nearest neighbors of the pilot field are populated with data symbols which fulfil a symmetry relation, said symmetry relation being selected from a group comprising:
• the nearest neighbors which precede and succeed the pilot field in its longitudinal direction are populated with a same data symbol;
• or when the pilot field is neither frequency-initial nor time-initial in a transmission and the pilot symbols are consecutive in time, the nearest neighbors, which are adjacent to the pilot field in frequency and coinciding with the pilot field in time, are populated with three independent data symbols and one data symbol which is given by a function of the three independent data symbols;
• and
• demodulating the data symbols constituting the at least two nearest neighbors of the pilot field using the symmetry relation between the data symbols.

A first node adapted to operate in a communication system employing filter bank multi-carrier (FBMC) modulation with a real symmetric pulse, comprising:

• a modulator for FBMC-modulating a signal comprising data symbols and predetermined pilot symbols;
• and
• a transmitter for transmitting the FBMC-modulated signal to enable channel estimation at a second node,
• a processor configured to generate the signal with a predetermined pilot field populated with two pilot symbols, which are either consecutive in frequency and coinciding in time or coinciding in frequency and consecutive in time, and in that at least two nearest neighbors of the pilot field are populated with data symbols which fulfil a symmetry relation, said symmetry relation being selected from a group comprising:
• the nearest neighbors which precede and succeed the pilot field in its longitudinal direction are populated with a same data symbol;
• or
• when the pilot field is neither frequency-initial nor time-initial in a transmission and the pilot symbols are consecutive in time, the nearest neighbors, which are adjacent to the pilot field in frequency and coinciding with the pilot field in time, are populated with three independent data symbols and one data symbol which is given by a function of the three independent data symbols.

A second node adapted to operate in a communication system employing filter bank multi-carrier (FBMC) modulation with a real symmetric pulse, comprising:

• a receiver for receiving a FBMC-modulated signal from a first node;
• a demodulator for demodulating symbols in a predetermined pilot field in the received FBMC-modulated signal;
• and
• a processor configured to perform channel estimation on the basis of the demodulated symbols and of predetermined pilot symbols, wherein the pilot field is populated with two symbols, which are either consecutive in frequency and coinciding in time or coinciding in frequency and consecutive in time, and wherein at least two nearest neighbors of the pilot field are populated with data symbols which fulfil a symmetry relation, said symmetry relation being selected from a group comprising:
• the nearest neighbors which precede and succeed the pilot field in its longitudinal direction are populated with a same data symbol;
• or
• when the pilot field is neither frequency-initial nor time-initial in a transmission and the pilot symbols are consecutive in time, the nearest neighbors, which are adjacent to the pilot field in frequency and coinciding with the pilot field in time, are populated with three independent data symbols and one data symbol which is given by a function of the three independent data symbols;
• and
• wherein the demodulator is configured to demodulate the data symbols constituting the at least two nearest neighbors of the pilot field using the symmetry relation between the data symbols.