Support of frequency diversity mode for block code based transmission in OFDMA
Transmitting a frame may include determining a numerology according to a channel bandwidth, indicating the numerology in a field of a frame, and transmitting the frame using the numerology. Receiving a frame may include receiving a preamble of a frame, determining a numerology using the preamble, and receiving later portions of the frame using the numerology. Transmitting a frame may include, for a transmission time slot, determining a value of a first subcarrier of a first Space-Time Stream (STS), determining a value of a second subcarrier of the first STS, and determining, according to complex conjugates or negative complex conjugates of the values of the first and second subcarriers of the first STS, respective values of second and first sub carriers of a second STS. Transmitting a constellation point of a frame may be performed using an orphan subcarrier pair.
1. A method for transmitting a frame using a wireless device, the method comprising:
determining, by the wireless device, a channel bandwidth of the frame;
determining, by the wireless device, a numerology of the frame according to the channel bandwidth, wherein determining the numerology includes selecting the numerology from among a first numerology and a second numerology;
providing, by the wireless device, an indication according to the numerology in a field of the frame; and
transmitting, by the wireless device, the frame using the numerology,
wherein each of the first numerology and the second numerology corresponds to mappings of subcarrier frequencies to respective roles, including:
at least one mapping of a first subcarrier frequency to a guard band role,
at least one mapping of a second subcarrier frequency to a DC subcarrier role, and
at least one mapping of a plurality of contiguous subcarrier frequencies to a subband role,
wherein the first numerology is different from the second numerology, and
wherein when the numerology is determined to be the second numerology:
the channel bandwidth of the frame includes a first 20 MHz bandwidth and a second 20 MHz bandwidth,
the mappings of subcarrier frequencies to respective roles in the first 20 MHz bandwidth by the second numerology does not correspond to the mappings of subcarrier frequencies to respective roles in the first numerology, and
the mappings of subcarrier frequencies to respective roles in the second 20 MHz bandwidth by the second numerology does not correspond to the mappings of subcarrier frequencies to respective roles in the first numerology.
2. The method of claim 1 , wherein the numerology is the first numerology when the channel bandwidth is equal to a pre-determined value, and the numerology is the second numerology when the channel bandwidth is not equal to the pre-determined value.
3. The method of claim 2 , wherein the pre-determined value is 20 MHz.
4. The method of claim 1 , wherein the numerology is the first numerology when the channel bandwidth is equal to a pre-determined value and the frame is an Orthogonal Frequency Division Multiple Access (OFDMA) frame, and the numerology is the second numerology when the channel bandwidth is not equal to the pre-determined value and the frame is an Orthogonal Frequency Division Multiple Access (OFDMA) frame.
5. The method of claim 4 , wherein the first numerology includes a numerology repeated across a plurality of subchannels of the frame, and
wherein each of the subchannels has a bandwidth equal to the predetermined value.
6. The method of claim 1 , wherein the numerology is the first numerology when the channel bandwidth is equal to a pre-determined value, the frame is an Orthogonal Frequency Division Multiple Access (OFDMA) frame, and the frame is to be transmitted to a receiving device having an operational channel bandwidth less than the channel bandwidth of the frame, and the numerology is the second numerology when the channel bandwidth is not equal to the pre-determined value, the frame is an Orthogonal Frequency Division Multiple Access (OFDMA) frame, and the frame is to be transmitted to a receiving device having an operational channel bandwidth equal to the channel bandwidth of the frame.
7. The method of claim 1 , wherein the indication according to the numerology includes an indication of a numerology scheme including the numerology.
8. The method of claim 1 , wherein determining the channel bandwidth of the frame includes determining the channel bandwidth of the frame according to one or more selected from the group consisting of an amount of information in the frame, a cardinality of a plurality of receiving stations of the frame, and capabilities of the receiving stations of the frame.
9. A method for receiving a frame using a wireless device, the method comprising:
receiving a preamble of the frame;
determining a numerology of the frame using the preamble, wherein the numerology includes selecting the numerology from among a first numerology and a second numerology; and
receiving a remaining portion the frame using the numerology,
wherein each of the first numerology and the second numerology corresponds to mappings of subcarrier frequencies to respective roles, including:
at least one mapping of a first subcarrier frequency to a guard band role,
at least one mapping of a second subcarrier frequency to a DC subcarrier role, and
at least one mapping of a plurality of contiguous subcarrier frequencies to a subband role,
wherein the first numerology is different from the second numerology, and
wherein when the numerology is determined to be the second numerology;
the channel bandwidth of the frame includes a first 20 MHz bandwidth and a second 20 MHz bandwidth,
the mappings of subcarrier frequencies to respective roles in the first 20 MHz bandwidth by the second numerology does not correspond to the mappings of subcarrier frequencies to respective roles in the first numerology, and
the mappings of subcarrier frequencies to respective roles in the second 20 MHz bandwidth by the second numerology does not correspond to the mappings of subcarrier frequencies to respective roles in the first numerology.
10. The method of claim 9 , wherein the preamble includes an indication corresponding to a numerology or a numerology scheme.
11. The method of claim 10 , further including:
determining a channel bandwidth of the frame,
wherein determining the numerology includes determining the numerology according to the channel bandwidth.
12. The method of claim 11 , wherein the indication corresponds to a numerology scheme,
wherein the numerology scheme includes a plurality of numerologies, and
wherein determining the numerology includes selecting as the numerology a numerology corresponding to the channel bandwidth from among the plurality of numerologies.