Transmission Using Nested OFDMA
A transmission of information within a wireless cellular network may include a first and second group of samples. A first group of samples is created comprising at least a first and a last subgroup, wherein the last subgroup is same as the first subgroup. A second group of samples created. A transformed set of samples produced by jointly transforming the created first and second group with a discrete Fourier transform (DFT). The transformed set of samples is expanded to produce an expanded set, and the expanded set is transformed with an inverse discrete Fourier transform (IDFT) to produce an OFDM symbol with a fractional payload. The first group of samples is a reference signal (RS), which is known to the receiver before the transmission occurs, while the second group of samples is information data.
1 . A method for transmitting in a communication system, comprising:
creating a first group of samples comprising at least a first and a last subgroup, wherein the last subgroup is same as the first subgroup;
creating a second group of samples; and
producing a transformed set of samples by jointly transforming the created first and second group with a discrete Fourier transform (DFT).
2 . Method of claim 1 , further comprising:
expanding the transformed set of samples to produce an expanded set; and
transforming the expanded set with an inverse discrete Fourier transform (IDFT) to produce an orthogonal frequency division multiple access (OFDM) symbol with a fractional payload.
3 . Method of claim 2 , wherein expanding comprises zero-padding the transformed set.
4 . Method of claim 2 , further comprising transmitting the OFDM symbol with a fractional payload, wherein the first group of samples is a reference signal (RS) which is known to a receiver before the transmission occurs.
5 . Method of claim 4 , further comprising producing a 0.5 ms slot structure comprising at least two OFDM symbols each with fractional payload containing reference signals (RS) and comprising a number of OFDM symbols with integral payload wherein the number is selected from the set {4,5}.
6 . Method of claim 2 , further comprising:
producing the first group of samples by applying an IDFT to a first baseline set of samples; and
producing the second group of samples by applying an IDFT to a second baseline set of samples.
7 . A method for receiving in a communications system, comprising:
receiving an orthogonal frequency division multiple access (OFDM) symbol with a fractional payload having at least two portions;
producing a transformed OFDM symbol by jointly transforming the a least two portions of the OFDM symbol with a discrete Fourier transform (DFT) to form a set of samples; and
transforming the set of samples with an inverse discrete Fourier transform (IDFT) to produce a first group of samples having at least a first subgroup and a last subgroup and a second group of samples, wherein the last subgroup is same as the first subgroup.
8 . Method of claim 7 , wherein the first group of samples is a reference signal which is known to a receiver before receiving the OFDM symbol.
9 . An apparatus for transmitting in a cellular communication system, comprising:
generation circuitry for creating a first group of samples comprising at least a first and a last subgroup, wherein the last subgroup is same as the first subgroup;
generation circuitry for creating a second group of samples; and
modulating circuitry coupled to the generation circuitry, operable to produce a transformed set of samples by jointly transforming the created first and second group with a discrete Fourier transform (DFT).
10 . The apparatus of claim 9 , wherein the modulating circuitry is further operable to:
expand the transformed set of samples to produce an expanded set; and to transform the expanded set with an inverse discrete Fourier transform (IDFT) to produce an orthogonal frequency division multiple access (OFDM) symbol with a fractional payload.