Wireless Diversity Transmission Using Nss-Based Frequency Mapping

The patent segments the data field transmission into multiple frequency diversity schemes based on the number of spatial streams (Nss). Different segmentation patterns are applied: for Nss=1, data is mapped to even/odd subcarriers; for Nss=2, data is segmented across two spatial streams with frequency hopping; for Nss≥3, data is divided into multiple groups with interleaved frequency mapping. This segmentation allows the data field to achieve frequency diversity similar to the preamble, mitigating narrow-band interference while maintaining RU-based frequency scheduling efficiency.

The patent introduces frequency dimension diversity by mapping data spatial streams to different frequency subcarriers in a distributed manner rather than contiguous allocation. Specifically, data from multiple spatial streams is interleaved across frequency subcarriers, creating frequency diversity in the horizontal dimension while maintaining spatial diversity in the vertical dimension. This dimensional transformation enables the system to achieve both multiuser diversity through RU allocation and frequency diversity through subcarrier mapping, resolving the interference issue without sacrificing communication efficiency.

The patent employs self-service mechanisms where the receiver autonomously determines the frequency diversity transmission scheme without explicit signaling from the transmitter. The determination is based on: (1) the number of spatial streams (Nss) which is already known from the preamble, (2) the RU allocation information which is publicly available, and (3) predefined mapping rules that correlate Nss values with specific diversity schemes. For example, when Nss=1, the receiver automatically applies even/odd subcarrier mapping; when Nss=2, it applies spatial stream interleaving. This eliminates the need for additional signaling bits while ensuring both transmitter and receiver use the same diversity scheme, thereby improving PER performance without increasing overhead.

The patent changes the parameter of diversity scheme selection from being explicitly signaled to being implicitly determined by existing parameters (Nss and RU allocation). By establishing a deterministic relationship between these parameters and the diversity scheme, the system transforms the signaling requirement into a parameter-based automatic selection mechanism. This parameter change approach maintains flexibility in diversity scheme selection while eliminating signaling overhead, as the receiver can compute the appropriate scheme from known system parameters.