Inter-numerology interference blocker in multi-numerology systems

A pre-equalization method for removing inter-numerology interference in order to enable numerology (numerology-NSC) with a narrow subcarrier spacing in a common frequency band and numerology (numerology-WSC) with a wide subcarrier spacing brought side-by-side in the common frequency band without placing a protective band between the narrow subcarrier spacing and the wide subcarrier spacing, wherein the pre-equalization method comprises:

• determining numerologies to be placed in the common frequency band;
• obtaining an integer Q by dividing the wide subcarrier spacing by the narrow subcarrier spacing;
• determining a number of numerology-WSC symbols to be used together with the obtained integer Q;
• placing numerology-NSC and numerology-WSC subcarriers side-by-side without a the protective band between the numerology-NSC and numerology-WSC subcarriers in a frequency dimension separately so as to obtain time signals by taking inverse discrete Fourier transforms separately;
• taking N-point inverse discrete Fourier transforms and generating an N-length time signal for numerology-NSC after placing the numerology-NSC subcarriers, wherein N is an integer;
• taking (N/Q)-point inverse discrete Fourier transforms and generating an (N/Q)-length time signal for numerology-WSC after placing the numerology-WSC subcarriers;
• adding a cyclic prefix of NCP length to a beginning of the N-length time signal of the numerology-NSC so as to obtain a numerology-NSC signal of (N+NCP) length;
• adding a cyclic prefix of (NCP/Q) length to a beginning of the (N/Q)-length time signal of for numerology-WSC so as to obtain a numerology-WSC signal of (N/Q+NCP/Q) length;
• adding Q numerology-WSC signals of the (N/Q+NCP/Q) length end-to-end and adding with the numerology-NSC signal of (N+NCP) length in time dimension and placing numerology-NSC and numerology-WSC side-by-side in the common frequency band which is generated to be side-by-side separately in a frequency dimension, wherein since numerology-WSC is shorter in time dimension than numerology-NSC then Q numerology-WSC signals are added end-to-end so as to assure that the numerology-WSC has a same length in the time dimension as the numerology-NSC so as to obtain a multi-numerology signal of N+NCP length in time placed side-by-side in the common frequency band;
• determining P-subcarriers adjacent to the numerology-WSC of the numerology-NSC placed in the common frequency band for removal of interference, wherein P is an integer;
• determining K-subcarriers adjacent to the numerology-NSC of the numerology-WSC placed in the common frequency band for removal of interference, wherein K is an integer;
• determining the P-subcarriers and the K-subcarriers taken from the numerology-NSC and the numerology-WSC for pre-equalization;
• linear modeling of interference of said P-subcarriers of numerology-NSC with adjacent K-subcarriers of numerology-WSC with discrete Fourier and inverse discrete Fourier transform matrices;
• linear modeling of interference of adjacent K-subcarriers of Q signal of numerology-WSC with said P-subcarriers of numerology-NSC with discrete Fourier and inverse discrete Fourier transformation matrices;
• modeling of an interference of adjacent P-subcarriers and K-subcarriers with each other with WINI matrix;
• obtaining an INI (Inter-Numerology Interference between the numerology-NSC and numerology-WSC signals) pre-equalization matrix of (P+Q*K)×(P+Q*K) size by using an inverse of the WINI matrix;
• generating a column vector of (P+Q*K)×1 size by placing the subcarriers of numerology-NSC and numerology-WSC one under the other, the column vector being an X column vector;
• multiplying the subcarriers by a pre-equalization matrix (WINI)−1 before the multi-numerology signals are generated;
• placing new symbols in the numerologies after multiplying the symbols to be used in numerology with the pre-equalization matrix, the new symbols being the numerology-NSC subcarrier symbols (P symbols) and the numerology-WSC subcarrier symbols corresponding to Q symbols on each of the K subcarriers (QK symbols) placed in the column vector, wherein Q denotes a numerology ratio representing the number of numerology-WSC symbols within one numerology-NSC symbol duration;
• and
• generating a multi-numerology signal with INI removed after placing the new symbols in the numerologies.