Systems and methods are provided for transmit signalling to configure a UE with a UE specific root to use in generating a Zhadoff Chu (ZC) sequence for reference signal transmission. With conventional LTE, a cell specific root is used within each cell. There is a need for a more flexible association between roots and UEs that, for example, allows for multiple roots to be associated with a cell. The provided approach may help with maintaining re-use distance as networks become denser. The method provided in this embodiment improves the capabilities of automatic driving and ADAS of electric vehicles. The method can be applied to vehicle networking, such as V2X, LTE-V, V2X, etc.

Systems and methods are provided for transmit signalling to configure a UE with a UE specific root to use in generating a Zhadoff Chu (ZC) sequence for reference signal transmission. With conventional LTE, a cell specific root is used within each cell. There is a need for a more flexible association between roots and UEs that, for example, allows for multiple roots to be associated with a cell. The provided approach may help with maintaining re-use distance as networks become denser. The method provided in this embodiment improves the capabilities of automatic driving and ADAS of electric vehicles. The method can be applied to vehicle networking, such as V2X, LTE-V, V2X, etc.

A method is provided to generate and control transmission of reference symbols in a synchronization subframe, wherein a reference symbol includes reference values mapped to a block of K subcarriers. The method includes generating data corresponding to a basic subsequence of KR1R2 reference values, where R1 and R2 are integers such that 1R1+R2<K, and mapping the data corresponding to the basic subsequence to an original range of KR1R2 contiguous subcarriers in the block such that there is a first set of R1 unmapped subcarriers above the original range of subcarriers and a second set of R2 unmapped subcarriers below the original range of subcarriers. Data corresponding to last R1 values in the basic subsequence is mapped to the first set of unmapped subcarriers. Data corresponding to first R2 values in the basic subsequence is mapped to the second set of unmapped subcarriers.

Methods, systems, and devices related to applying a spreading code to reference signals are described. In one exemplary aspect, a method for wireless communication includes receiving a message indicating a set of control options available to the mobile device for data transmissions. The method includes selecting a spreading code sequence from a number of spreading code sequences, wherein the spreading code sequence corresponds to a control option in the set of control options, wherein the number of spreading code sequences is greater than a length of each of the spreading code sequence, and wherein the spreading code sequences are generated using a method when the length of each of the spreading code sequences is greater than or equal to a value. The method also includes generating a plurality of reference signal symbols using the spreading code sequence, and transmitting the plurality of reference signal symbols.

Methods, systems, and devices related to applying a spreading code to reference signals are described. In one exemplary aspect, a method for wireless communication includes receiving a message indicating a set of control options available to the mobile device for data transmissions. The method includes selecting a spreading code sequence from a number of spreading code sequences, wherein the spreading code sequence corresponds to a control option in the set of control options, wherein the number of spreading code sequences is greater than a length of each of the spreading code sequence, and wherein the spreading code sequences are generated using a method when the length of each of the spreading code sequences is greater than or equal to a value. The method also includes generating a plurality of reference signal symbols using the spreading code sequence, and transmitting the plurality of reference signal symbols.

A communication method performed by a base station in a wireless communication network is disclosed. The base station notifies a terminal of a cyclic shift increment N.sub.CS configuration information indicating an N.sub.CS value. The base station then receives from the terminal a random access preamble related to the N.sub.CS value indicated by the N.sub.CS configuration information. The N.sub.CS value belongs to a set of cyclic shift increments including all of the following cyclic shift increments of 0, 13, 15, 18, 22, 26, 32, 38, 46, 59, 76, 93, 119, 167, 279, and 419.

A communication method performed by a base station in a wireless communication network is disclosed. The base station notifies a terminal of a cyclic shift increment N.sub.CS configuration information indicating an N.sub.CS value. The base station then receives from the terminal a random access preamble related to the N.sub.CS value indicated by the N.sub.CS configuration information. The N.sub.CS value belongs to a set of cyclic shift increments including all of the following cyclic shift increments of 0, 13, 15, 18, 22, 26, 32, 38, 46, 59, 76, 93, 119, 167, 279, 419.

A signal generator 10 generates an OOK (on-off keying) modulation signal by mapping a CAZAC (constant amplitude zero auto-correlation) sequence to N subcarriers (N being an integer that is greater than or equal to 2) arranged at a determined interval among M subcarriers (M being an integer that is greater than or equal to 3) that are adjacent in the frequency domain, carrying out inverse fast Fourier transform (IFFT) processing on the mapped CAZAC sequence, and carrying out Manchester coding on a time domain signal generated by the IFFT processing. A radio transmitter 107 transmits the OOK modulation signal.

A method for operating a transmitting device to communicate with a receiving device is described herein. The method includes the step of the transmitting device selecting a root index value from a set of root index values. The method further includes the step of the transmitting device generating a frequency domain Constant Amplitude Zero Auto-Correlation sequence based on the selected root index value. The method further includes the step of the transmitting device modulating the Constant Amplitude Zero Auto-Correlation sequence by a pseudo-noise sequence. The method further includes the step of the transmitting device generating an Orthogonal Frequency Division Multiplexing symbol, wherein the frequency domain Constant Amplitude Zero Auto-Correlation sequence modulated by the pseudo-noise sequence defines subcarrier values for the Orthogonal Frequency Division Multiplexing symbol. The method further includes the step of the transmitting device transmitting the Orthogonal Frequency Division Multiplexing symbol as an initial Orthogonal Frequency Division Multiplexing symbol of a preamble of a frame to the receiving device.

A method for operating a transmitting device to communicate with a receiving device is described herein. The method includes the step of the transmitting device selecting a root index value from a set of root index values. The method further includes the step of the transmitting device generating a frequency domain Constant Amplitude Zero Auto-Correlation sequence based on the selected root index value. The method further includes the step of the transmitting device modulating the Constant Amplitude Zero Auto-Correlation sequence by a pseudo-noise sequence. The method further includes the step of the transmitting device generating an Orthogonal Frequency Division Multiplexing symbol, wherein the frequency domain Constant Amplitude Zero Auto-Correlation sequence modulated by the pseudo-noise sequence defines subcarrier values for the Orthogonal Frequency Division Multiplexing symbol. The method further includes the step of the transmitting device transmitting the Orthogonal Frequency Division Multiplexing symbol as an initial Orthogonal Frequency Division Multiplexing symbol of a preamble of a frame to the receiving device.