User equipment, UE , comprising: an M-point Discrete Fourier transform, DFT, block , wherein M is the number of points of the DFT; processing circuitry configured to: generate a Time Division Duplex, TDD, frame comprising multiple blocks, each block comprising Guard Interval DFT-Spread-Orthogonal Frequency Division Multiplexing, GI-DFT-s-OFDM, symbols and a dynamically determined guard interval, GI, sequence, wherein zeros are placeholders for the guard interval sequence to be inserted and are supplied to the M-point DFT block ; and configure a transceiver to transmit the TDD frame to an enhanced NodeB, eNB , wherein the GI sequence originates from at least one of: a frequency domain generated Zadoff-Chu, ZC, sequence upsampled by a factor of 2 using an Inverse Fast Fourier Transform, IFFT, of size two times a length of the ZC sequence, a ZC sequence whose base sequence of each possible GI length for both uplink and downlink communications is dependent on the eNB to which the UE is attached, and a ZC sequence whose base sequence for uplink communications is a cyclically shifted and cyclically extended version of a common base sequence that is dependent on the UE . an M-point Discrete Fourier transform, DFT, block , wherein M is the number of points of the DFT; processing circuitry configured to: generate a Time Division Duplex, TDD, frame comprising multiple blocks, each block comprising Guard Interval DFT-Spread-Orthogonal Frequency Division Multiplexing, GI-DFT-s-OFDM, symbols and a dynamically determined guard interval, GI, sequence, wherein zeros are placeholders for the guard interval sequence to be inserted and are supplied to the M-point DFT block ; and configure a transceiver to transmit the TDD frame to an enhanced NodeB, eNB , generate a Time Division Duplex, TDD, frame comprising multiple blocks, each block comprising Guard Interval DFT-Spread-Orthogonal Frequency Division Multiplexing, GI-DFT-s-OFDM, symbols and a dynamically determined guard interval, GI, sequence, wherein zeros are placeholders for the guard interval sequence to be inserted and are supplied to the M-point DFT block ; and configure a transceiver to transmit the TDD frame to an enhanced NodeB, eNB , wherein the GI sequence originates from at least one of: a frequency domain generated Zadoff-Chu, ZC, sequence upsampled by a factor of 2 using an Inverse Fast Fourier Transform, IFFT, of size two times a length of the ZC sequence, a ZC sequence whose base sequence of each possible GI length for both uplink and downlink communications is dependent on the eNB to which the UE is attached, and a ZC sequence whose base sequence for uplink communications is a cyclically shifted and cyclically extended version of a common base sequence that is dependent on the UE . a frequency domain generated Zadoff-Chu, ZC, sequence upsampled by a factor of 2 using an Inverse Fast Fourier Transform, IFFT, of size two times a length of the ZC sequence, a ZC sequence whose base sequence of each possible GI length for both uplink and downlink communications is dependent on the eNB to which the UE is attached, and a ZC sequence whose base sequence for uplink communications is a cyclically shifted and cyclically extended version of a common base sequence that is dependent on the UE . <EOS>