Patent ID: 11962445
Assignee: VOLKSWAGEN AKTIENGESELLSCHAFT
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 5:
6. A device for detecting Orthogonal Time Frequency Space (OTFS) pilot interference comprising:
a signal input for receiving delay-Doppler-domain samples y[k,l] of a received OTFS delay-Doppler frame, associated with a delay-Doppler grid, wherein 0≤k≤N−1 and 0≤l≤M−1 wherein the grid has N grid spaces associated with a Doppler dimension quantized in, 1
  NT, and M grid spaces in the delay dimension quantized in, 1
   
    
     M
     ·
     Δ
    
    ⁢
    f
   
  
  ,, wherein M an N are integers, wherein the delay-Doppler domain samples y[k,l] are derived by a two-dimensional symplectic Fourier transformation from time-frequency domain samples Y[n,m] resulting from sampling time-varying received OFTS coded signal N times with a sampling time T and for M frequency subcarriers with a bandwidth resolution of Δf each and wherein 0≤n≤N−1 and 0≤m≤M−1; and
an integration unit for summing the squares of the amplitudes of the received delay-Doppler domain samples y[k,l], which are also evaluated for channel estimation, to establish the received non-interfering pilot power Ppilot and for summing the squares of the amplitudes of all the samples y[k,l] of a complete delay-Doppler grid to establish a total received frame power Pframe;
a calculation unit to retrieve OFTS transmission parameter comprising information about the number of guard symbol spaces and pilot symbol spaces in the OFTS transmission frame and configured to retrieve received non-interfering pilot power Ppilot_power as well as the total received frame power Pframe and configured to calculate a pilot power ratio Rpilot_power by dividing the received non-interfering pilot power Ppilot_power by the total received frame power Pframe as well as to calculate a guard space ratio Rguard_space by dividing the number of guard and pilot symbol spaces Aguard_space in a transmitted OFTS frame by the total number of grid spaces Aframe in the transmitted OFTS frame;
a comparator unit for comparing the pilot power ratio Rpilot_power with the guard space ration Rguard_space; and
an evaluation unit for providing an interference signal when the pilot power ratio Rpilot_power and the guard space ration Rguard_space deviate by more than an acceptance threshold.