Reference Signal Structure for OFDM Based Transmissions

Abstract

A method for transmitting a plurality of sequences across a plurality of bands of a wireless spectrum is described in which a first sequence Is produced using a set of reference signal sequences, wherein the set of reference signal sequences comprises at least CAZAC sequences and near-CAZAC sequences. A second sequence is also produced. The first sequence is transmitted in a first band of the wireless spectrum, and the second sequence is transmitted in a second band of the wireless spectrum. The first and the second sequences are transmitted concurrently by a same user equipment.

1 - 15 . (canceled) 
     
     
         16 . An apparatus for transmitting a plurality of sequences across a plurality of bands of a wireless spectrum, comprising:
 logic for producing a first sequence using a set of reference signal sequences;   logic for producing a second sequence; and   transmitter circuitry operable to transmit the first sequence in a first band of the wireless spectrum and to transmit the second sequence in a second band of the wireless spectrum.   
     
     
         17 . The apparatus of  claim 16 , wherein the set of reference signal sequences comprises at least one of CAZAC sequences and near-CAZAC sequences,
 wherein said CAZAC sequences comprise Zadoff-Chu (ZC) sequences, and   wherein said near-CAZAC sequences have a form exp(j*.pi.*.phi.(n)/4).   
     
     
         18 - 24 . (canceled) 
     
     
         25 . The apparatus of  claim 16 , wherein said transmitter circuitry is operable to transmit the first and the second sequences concurrently. 
     
     
         26 . The apparatus of  claim 16 , wherein said logic for producing the first sequence comprises logic for modulation by a phase ramp. 
     
     
         27 . The apparatus of  claim 26 , wherein said phase ramp parameters are indicated by received message. 
     
     
         28 . The apparatus of  claim 16 , wherein said logic for producing a first sequence comprises a cyclic shift. 
     
     
         29 . The apparatus of  claim 17 , wherein the length of .phi.(n) is an integral multiple of 12. 
     
     
         30 . The apparatus of  claim 16 , wherein the second sequence is selected from a set of reference signal sequences. 
     
     
         31 . The apparatus of  claim 30 , wherein said logic to produce a second sequence further comprises multiplication by at least one element of a cover sequence. 
     
     
         32 . The apparatus of  claim 31 , wherein the cover sequence is selected from a group of cover sequences. 
     
     
         33 . The apparatus of  claim 32 , wherein the cover sequence selection is indicated by a received message. 
     
     
         34 . The apparatus of  claim 31 , wherein the cover sequence length equals the number of tone blocks allocated to the reference signal sequence. 
     
     
         35 . A method for transmitting a plurality of sequences across a plurality of bands of a wireless spectrum, comprising:
 producing a first sequence using a set of reference signal sequences, wherein the set of reference signal sequences comprises at least CAZAC sequences and near-CAZAC sequences;   selecting a reference signal sequence from the set of reference signal sequences;   producing a second sequence using said set of reference signal sequences by multiplying each entry of the selected reference signal sequence by a covering element;   transmitting the first sequence in a first band of the wireless spectrum; and   transmitting the second sequence in a second band of the wireless spectrum, wherein the first and the second sequences are transmitted concurrently by a same user equipment.   
     
     
         36 . A method for transmitting a plurality of sequences across a plurality of bands of a wireless spectrum, comprising:
 producing a first sequence using a set of reference signal sequences, wherein the set of reference signal sequences comprises at least CAZAC sequences and near-CAZAC sequences; producing a covering sequence comprising at least a second covering element; and   selecting a reference signal sequence from the set of reference signal sequences;   adding a phase ramping sequence to the phase component of the selected reference signal sequence; producing a second sequence using said set of reference signal sequences including multiplying the second covering element with each entry of the selected reference signal sequence;   transmitting the first sequence in a first band of the wireless spectrum; and   transmitting the second sequence in a second band of the wireless spectrum, wherein the first and the second sequences are transmitted concurrently by a same user equipment.