System, method, and apparatus for low power cyclic prefix (CP) based hybrid spread waveforms
Systems, methods, and instrumentalities are disclosed for generating, transmitting, and/or receiving a hybrid spread waveform. The hybrid spread waveform may include a data portion and a hybrid guard interval (HGI) portion. The HGI portion may include a fixed prefix portion or a fixed suffix portion, and an adaptive low power tail (LPT) portion. The fixed prefix portion or the fixed suffix portion is a low power cyclic prefix (LPCP). The LPCP may be generated at least based on at least the channel delay spread and a power regrowth length. The adaptive LPT portion may be generated using a zero tail (ZT). The LPT is generated by inserting zeros at IFFT or DFT processing stage. A part of the adaptive LPT portion is used to carry data or control information. A waveform may be switched between a hybrid spread waveform and a fixed-CP waveform, e.g., via control signaling.
1. A method for generating a hybrid spread waveform, the method comprising:
generating the hybrid spread waveform comprising a data portion and a hybrid guard interval (HGI) portion, wherein the HGI portion comprises a fixed portion and an adaptive low power tail (LPT) portion, wherein the fixed portion comprises a fixed prefix portion or a fixed suffix portion, wherein the adaptive LPT portion is dynamically adapted based on channel delay spread and low power cyclic prefix (LPCP) length, wherein the fixed portion comprises a fixed LPCP; and
transmitting the generated hybrid spread waveform comprising the data portion and the HGI portion.
2. The method of claim 1 , wherein the LPCP length is calculated based on delay spread and power regrowth length.
3. The method of claim 1 , wherein the adaptive LPT portion is generated using a zero tail (ZT), wherein the LPT is generated by inserting zeros at inverse fast Fourier transform (IFFT) or discrete Fourier transform (DFT) processing stage.
4. The method of claim 1 , further comprising receiving one or more of a hybrid guard interval (HGI) length, an adaptive low power tail (LPT) length, or an indication of a number of zeros inserted before FFT or DFT, wherein one or more of the hybrid guard interval (HGI) length, the adaptive low power tail (LPT) length, or the indication of the number of zeros are received via a physical control channel, a medium access control information element (MAC IE) or radio resource control (RRC) signaling.
5. The method of claim 1 , wherein a part of the adaptive LPT portion is used to carry data or control information.
6. The method of claim 1 , wherein the fixed portion is a zero power prefix, and wherein the zero power prefix is generated based on zero padding (ZP).
7. The method of claim 1 , further comprising receiving a control signaling indicating switching waveform type between a fixed-CP waveform and the hybrid spread waveform.
8. A wireless transmit/receive unit (WTRU) comprising:
a processor configured to at least:
generate a hybrid spread waveform comprising a data portion and a hybrid guard interval (HGI) portion, wherein the HGI portion comprises a fixed portion and an adaptive low power tail (LPT) portion, wherein the fixed portion comprises a fixed prefix portion or a fixed suffix portion, wherein the adaptive LPT portion is dynamically adapted based on channel delay spread and low power cyclic prefix (LPCP) length, wherein the fixed portion comprises a fixed LPCP; and
a transmitter configured to at least transmit the generated hybrid spread waveform comprising the data portion and the HGI portion.
9. The WTRU of claim 8 , wherein the LPCP length is calculated based on delay spread and power regrowth length.
10. The WTRU of claim 8 , wherein the adaptive LPT portion is generated using a zero tail (ZT), wherein the LPT is generated by inserting zeros at inverse fast Fourier transform (IFFT) or discrete Fourier transform (DFT) processing stage.
11. The WTRU of claim 8 comprising a receiver configured to at least receive one or more of a hybrid guard interval (HGI) length, an adaptive low power tail (LPT) length, or an indication of a number of zeros inserted at inverse fast Fourier transform (IFFT) or discrete Fourier transform (DFT) processing stage.
12. The WTRU of claim 11 , wherein one or more of the hybrid guard interval (HGI) length, the adaptive low power tail (LPT) length, or the indication of the number of zeros is received via a physical control channel, a medium access control information element (MAC IE) or radio resource control (RRC) signaling.
13. The WTRU of claim 8 , wherein a part of the adaptive LPT portion is used to carry data or control information.
14. The WTRU of claim 8 , wherein the fixed portion is a zero power prefix, and wherein the zero power prefix is generated based on zero padding (ZP).
15. The WTRU of claim 8 comprising a receiver configured to at least receive a control signaling indicating switching waveform type between a fixed-CP waveform and the hybrid spread waveform.