WLAN MIMO Packet Signaling for SU/MU Encoding Compatibility
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Solution Overview
Problem
Next-generation WLAN systems require a method to transmit and receive MIMO packets efficiently, considering different encoding schemes and modulation and coding schemes for single user (SU)-MIMO and multi user (MU)-MIMO transmissions, as existing technologies struggle to support varying capabilities among multiple stations (STAs) and ensure compatible data transmission.
Innovation Solution
A method and apparatus for transmitting MIMO packets that include spatial stream sets encoded using either LDPC or BCC encoding schemes, with control information indicating whether the transmission is SU-MIMO or MU-MIMO, and specifying the appropriate encoding scheme for each spatial stream set, allowing STAs to decode packets based on their supported schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MU-MIMO transmission is used to transmit packets to multiple STAs simultaneously, then productivity is improved, but device complexity increases due to the need to signal different MCS indices to different STAs
Solution Approach 1:
The control information is segmented into two parts: VHT-SIG A field containing common information for all STAs (including a 1-bit MU-MIMO indicator), and VHT-SIG B field containing STA-specific information. This segmentation allows efficient signaling by separating common control data from individualized data, reducing overall signaling complexity while enabling MU-MIMO transmission to multiple STAs simultaneously
Solution Approach 2:
The patent introduces a new dimension of control information organization by adding the MU-MIMO indicator bit in the VHT-SIG A field, which enables receivers to differentiate between SU-MIMO and MU-MIMO transmissions. This dimensional addition allows the system to handle multiple transmission modes without increasing the complexity of individual field structures
2Adaptability or versatility
If different encoding schemes are applied to different spatial stream sets for different STAs, then adaptability is improved, but device complexity increases due to the need to manage multiple encoding schemes
Solution Approach 1:
Different encoding schemes (BCC or LDPC) are applied locally to different spatial stream sets based on the capabilities of specific STAs. The VHT-SIG B field contains encoding scheme information specific to each STA's spatial streams, allowing each receiver to decode its assigned streams using the appropriate scheme while maintaining overall system adaptability without requiring all STAs to support all encoding schemes
Solution Approach 2:
The control information structure is designed to be universal by incorporating fields that can accommodate both SU-MIMO and MU-MIMO scenarios, as well as both BCC and LDPC encoding schemes. The VHT-SIG A and B fields together provide a unified framework that handles diverse transmission configurations through standardized field definitions that adapt to specific transmission requirements
Data Source
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AI summary
A method of transmitting a multiple input multiple output (MIMO) packet by a transmitter in a wireless local area network (WLAN) system is provided. The method includes: generating a MIMO packet including at least one spatial stream set transmitted respectively to at least one receiver, wherein each spatial stream set is encoded on the basis of one of two encoding schemes; transmitting first control information including a MIMO indicator and a first modulation and coding scheme (MCS) field, wherein the MIMO indicator indicates whether the MIMO packet is for single user (SU)-MIMO or multi user (MU)-MIMO, and the first MCS field indicates an MCS used for the MIMO packet if the MIMO packet is for SU-MIMO transmission, and indicates an encoding scheme applied for each of the spatial stream sets if the MIMO packet is for MU-MIMO transmission; and transmitting the MIMO packet to at least one receiver. The two encoding schemes are low-density parity check (LDPC) encoding scheme and binary convolution coding (BCC) encoding.