A WTRU may comprise circuitry configured to determine a sequence, from a set of sequences comprising 0 0 0 0 0 0 1 1 0 1 1 0, 0 0 0 0 0 1 0 0 0 1 1 1 and 0 0 0 0 0 1 1 1 0 1 1 1. The WTRU may further comprise a transmitter configured to transmit a DMRS, derived from the determined sequence.

A WTRU may comprise circuitry configured to determine a sequence, from a set of sequences comprising 0 0 0 0 0 0 1 1 0 1 1 0, 0 0 0 0 0 1 0 0 0 1 1 1 and 0 0 0 0 0 1 1 1 0 1 1 1. The WTRU may further comprise a transmitter configured to transmit a DMRS, derived from the determined sequence.

Code generating including generating a non-correlation sequence for RS of a first resource block; spreading spectrums of elements in the non-correlation sequence for RS to be mapped to a first frequency resource of the first resource block, by using a first group of codes; second spreading spectrums of elements in the non-correlation sequence for RS to be mapped to a second frequency resource of the first resource block, by using a second group of Codes; the first and second frequency resources are adjacent frequency resources in frequency resource elements used for RS transmission in the first resource block, and the first and second groups of Codes are mirrors in column to each other; and mapping the spectrum-spread elements to the first and second frequency resources, respectively.

Code generating including generating a non-correlation sequence for RS of a first resource block; spreading spectrums of elements in the non-correlation sequence for RS to be mapped to a first frequency resource of the first resource block, by using a first group of codes; second spreading spectrums of elements in the non-correlation sequence for RS to be mapped to a second frequency resource of the first resource block, by using a second group of Codes; the first and second frequency resources are adjacent frequency resources in frequency resource elements used for RS transmission in the first resource block, and the first and second groups of Codes are mirrors in column to each other; and mapping the spectrum-spread elements to the first and second frequency resources, respectively.

A device for modulating communication signals comprises a transceiver for receiving and transmitting the signal, a storage medium storing computer implemented programme code components to generate sequences and a processor in communication with the storage medium and transceiver. The processor executes computer implemented programme code components to generate a family of shift sequences or arrays using exponential, logarithmic or index functions and a polynomial or a rational function polynomial in i.sub.p1 for a finite field .sub.p of prime p. Multiple columns of the arrays are substituted with pseudo-noise sequences or other suitable good correlation sequences in a cyclic shift equal to the shift sequence for the respective column to generate a substituted array. The substituted array, or a sequence unfolded using the CRT from the array when the array dimensions are relatively prime, is applied to a carrier wave of the communication signal to generate a modulated communication 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.

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.

A device for modulating communication signals comprises a transceiver for receiving and transmitting the signal, a storage medium storing computer implemented programme code components to generate sequences and a processor in communication with the storage medium and transceiver. The processor executes computer implemented programme code components to generate a family of shift sequences or arrays using exponential, logarithmic or index functions and a polynomial or a rational function polynomial in t.sub.p1 for a finite field .sub.p of prime p. Multiple columns of the arrays are substituted with pseudo-noise sequences or other suitable good correlation sequences in a cyclic shift equal to the shift sequence for the respective column to generate a substituted array. The substituted array, or a sequence unfolded using the CRT from the array when the array dimensions are relatively prime, is applied to a carrier wave of the communication signal to generate a modulated communication signal.