High speed overlay mode for burst data and real time streaming (audio) applications
View Patent ↗In a wireless 802.15.4 communication system ( 300 ), a high-speed data frame structure ( 340 ) is provided which uses the 802.15.4 SHR structure that is spread modulated to obtain the synchronization benefits of the 802.15.4 protocol, but which uses a modified data frame structure for the payload portion without using spreading to thereby improve its transmission efficiency. The transmission efficiency can be further increased by increasing the size of the data payload (and correspondingly, the frame length size).
1. In a wireless personal area network in accordance with IEEE 802.15.4 protocol, a method for communicating data to a node in the wireless personal area network comprising:
receiving a data payload to be transmitted to the node;
generating from the data payload an extended media access control (MAC) protocol data unit (MPDU) structure comprising a MAC header and MAC footer;
generating from the extended MPDU a packet header (PHR) structure;
generating a predetermined synchronization header (SHR) structure for a high speed overlay mode by applying spreading code modulation to only an 802.15.4 preamble sequence;
generating a high-speed data frame from the predetermined SHR structure, PHR structure and extended MPDU structure; and
forwarding the high-speed data frame for routing to a destination node in the wireless personal area network.
2. The method of claim 1 , where generating a predetermined SHR structure comprises performing spreading and pulse-shaping on the 801.15.4 preamble sequence and a start-of-frame delimiter (SFD) structure.
3. The method of claim 1 , where generating from the data payload an extended MPDU structure comprises performing OQPSK modulation without spreading on the extended MPDU structure.
4. The method of claim 1 , where generating a predetermined synchronization header (SHR) structure comprises generating a start-of-frame delimiter (SFD) structure having a predetermined value that is different from a standard SFD value in the 802.15.4 protocol.
5. The method of claim 4 , where the SFD structure has a predetermined value of C5.
6. The method of claim 4 , where the SFD structure has a predetermined value having a large hamming distance from the standard SFD value in the 802.15.4 protocol.
7. The method of claim 1 , where generating a high-speed data frame comprises appending the predetermined SHR structure and PHR structure as a header to the extended MPDU structure.