Obviousness

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print(google_search.search(queries=["35 U.S.C. § 103 obviousness analysis", "person having ordinary skill in the art wireless communication networks", "motivation to combine prior art wireless communication networks"]))
thought
The user is asking for an obviousness analysis of US patent 10020919 under 35 U.S.C. § 103, building on the previously generated "Prior Art" section. I need to:

1. Identify combinations of the cited prior art references.
2. Explain why these combinations would render the claims of US10020919 obvious.
3. Provide a motivation for a Person Having Ordinary Skill in the Art (PHOSITA) to combine these references.

I will focus on independent claims 1, 10, and 15, as they define the broadest scope of the invention.

For Independent Claims 10 and 15 (CSI Feedback Procedures):
The "Prior Art" section highlighted US 2014/0286307 A1 as highly relevant, noting that its patentability might hinge on the '919 patent's conditional procedure for single-user vs. multi-user feedback. I need to consider if other references, particularly those discussing trigger frames and MU uplink access (like US 9,674,833 B2 and US 10,237,929 B2), could be combined with US 2014/0286307 A1 to teach or suggest this conditional logic.

• US 2014/0286307 A1: Teaches NDPA, NDP, and a trigger frame for multi-user CSI feedback.
• US 9,674,833 B2 / US 10,237,929 B2: Teach trigger frames for resource allocation in uplink multi-user scenarios.

The key question is whether a PHOSITA, looking at US 2014/0286307 A1 (multi-user triggered feedback) and general knowledge of efficient wireless communication (e.g., avoiding overhead when unnecessary), would be motivated to simplify the process for single users by omitting the trigger frame. If a system can support single-user feedback, and a sounding announcement only lists one user, it would be logical to send feedback directly to reduce latency and overhead associated with an unnecessary trigger frame.

For Independent Claim 1 (Scrambling of CTS frames):
The "Prior Art" section states that "none of the cited references appear to directly address the specific method of deriving a second scrambling sequence for a CTS frame as a cyclic shift of the first scrambling sequence from a received MU-RTS frame." This suggests that finding an obviousness combination for claim 1 might be more challenging based solely on the cited art. I will need to consider whether general principles of scrambling, sequence generation, or RF combining in the context of MU-MIMO/OFDMA (which are broadly discussed in the patent's background and classifications) would motivate a PHOSITA to arrive at this specific solution. The patent itself highlights the necessity for identical scrambling sequences for successful RF combining (see "scrambling sequences for two or more transmissions to be successfully RF-combined, all of the two or more transmissions must use a same scrambling sequence"). If prior art teaches that multiple stations responding simultaneously need to use the same scrambling sequence for RF combining, and also teaches deriving parameters from a received frame, then using a cyclic shift derived from the MU-RTS scrambler initialization for the CTS frame might be considered an obvious way to achieve that common scrambling sequence.

I will need to look for common general knowledge in the field (which a PHOSITA would possess) regarding:

• Scrambling techniques and maximal length sequences.
• The importance of common scrambling sequences for RF combining in multi-user responses.
• Methods for deriving parameters for response frames from initiating frames.

Let's refine the PHOSITA definition and the motivation to combine.

PHOSITA for this patent: A person having ordinary skill in the art (PHOSITA) in the field of wireless communication networks, particularly those involved in the development and standardization of IEEE 802.11 (WLAN) systems, including MU-MIMO and OFDMA technologies. This person would understand MAC and PHY layer protocols, frame structures, channel sounding, interference avoidance, and data scrambling techniques. They would be familiar with the trade-offs between efficiency, overhead, and performance in wireless systems.

General motivation to combine prior art:

• Improving efficiency (reducing overhead, latency).
• Enhancing throughput in multi-user environments.
• Ensuring reliable communication and successful RF combining.
• Adapting existing techniques (like single-user sounding or basic scrambling) to new multi-user or high-efficiency WLAN standards.

Now I will construct the obviousness arguments for each independent claim.## Obviousness Analysis of US Patent 10,020,919 under 35 U.S.C. § 103

An invention is deemed obvious under 35 U.S.C. § 103 if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). This analysis considers the scope and content of the prior art, the differences between the prior art and the claims, the level of ordinary skill in the art, and any secondary considerations of non-obviousness. The priority date for US Patent 10,020,919 is October 12, 2015.

A PHOSITA in this field would be a wireless communication engineer or researcher with experience in IEEE 802.11 standards, MAC and PHY layer design, multi-user (MU) communication (including MU-MIMO and OFDMA), channel sounding, and data scrambling techniques. This individual would be motivated to improve spectral efficiency, reduce latency, and enhance overall throughput and reliability in dense wireless network environments.

Obviousness of Independent Claims 10 and 15 (CSI Feedback Procedures)

Independent claims 10 and 15 detail a conditional method for obtaining/transmitting Channel State Information (CSI) feedback based on the number of stations designated in a Null Data Packet Announcement (NDPA). If only one station is designated, CSI feedback is transmitted directly after a Null Data Packet (NDP). If multiple stations are designated, a trigger frame is used to coordinate a multi-user CSI feedback transmission.

Combination of Prior Art:

1. US 2014/0286307 A1 (Qualcomm): This publication is highly relevant as it describes a multi-user (MU-MIMO) sounding procedure where an Access Point (AP) sends a sounding announcement frame (NDPA) followed by a sounding packet (NDP). It then transmits a trigger frame to poll multiple STAs for their CSI feedback, which is returned in a multi-user uplink transmission. This reference clearly teaches the triggered multi-user CSI feedback mechanism.

2. US 9,674,833 B2 (Intel) / US 10,237,929 B2 (Intel): These patents (and application) describe an apparatus and method for multi-user uplink access, specifically the use of a trigger frame by an AP to solicit uplink multi-user transmissions from multiple stations, including resource unit allocation information. While primarily focused on general uplink transmissions, they reinforce the concept of using trigger frames for coordinating multiple users.

Motivation for Combination and Obviousness Rationale:

A PHOSITA, seeking to optimize channel sounding procedures in a wireless network as taught by US 2014/0286307 A1, would readily recognize that transmitting an unnecessary trigger frame introduces undesirable overhead and latency when only a single station is being polled for CSI feedback. The background of the '919 patent itself emphasizes that "sounding operations may contribute to the total amount of overhead in a wireless network. Therefore it is advantageous for sounding processes, including sounding processes used for UL MU transmissions, to be efficient."

Given the teaching in US 2014/0286307 A1 for multi-user triggered feedback, a PHOSITA would be motivated to streamline this process for single-user scenarios. It would be an obvious design choice to eliminate the trigger frame when only one station needs to respond, allowing that single station to transmit its CSI feedback directly after the NDP, as is common practice for immediate responses in single-user acknowledgments or feedback mechanisms (e.g., SIFS response times after a data frame in IEEE 802.11 standards, as generally understood by a PHOSITA and illustrated in FIG. 4 and FIG. 5 of the '919 patent). This would reduce overhead and latency associated with waiting for and processing a trigger frame that, in a single-user context, would serve no multi-user coordination purpose. The PHOSITA would adapt the multi-user procedure of US 2014/0286307 A1 by applying known principles of efficiency and single-user direct responses to create the conditional logic described in claims 10 and 15. The difference lies in selecting the most efficient known method (direct response for single user, triggered response for multiple users) based on the context provided by the NDPA, which would be an obvious engineering choice to reduce overhead.

Therefore, the combination of US 2014/0286307 A1 with the general knowledge of a PHOSITA concerning efficient wireless protocols and the desire to minimize overhead for single-user communications would render claims 10 and 15 obvious.

Obviousness of Independent Claim 1 (Scrambling for CTS Frames)

Independent claim 1 describes a method where a wireless device receives an MU-RTS frame with first scrambled data, descrambles it using a first scrambling sequence, and then generates and transmits a CTS frame with second scrambled data using a second scrambling sequence. The crucial element is that the second scrambling sequence is generated based on the first scrambling sequence, specifically by using the "foremost 7 bits" of the first scrambled data (prior to descrambling) as the initial state for the second scrambling sequence. This effectively makes the second sequence a cyclically shifted version of the first.

Lack of Direct Prior Art Combination:

The "Prior Art" section explicitly states that "none of the cited references appear to directly address the specific method of deriving a second scrambling sequence for a CTS frame as a cyclic shift of the first scrambling sequence from a received MU-RTS frame." The cited prior art focuses on MU uplink access and CSI feedback, not the specific intricacies of scrambling sequences for RTS/CTS exchanges in an MU context, particularly for RF-combining.

Rationale for Potential Non-Obviousness (based on provided prior art):

Based solely on the prior art references provided and their descriptions, there is no clear combination that would render independent claim 1 obvious. The unique aspect of RF-combining multiple CTS frames from different stations requires that "all of the two or more transmissions must use a same scrambling sequence." The method of deriving the exact same scrambling sequence (or a precisely related one, like a cyclic shift) among multiple independent responding stations based on a parameter from the initiating frame (MU-RTS) is a specific technical solution to enable successful RF combining, which is not clearly taught or suggested by the cited prior art.

While a PHOSITA would understand basic scrambling (as illustrated in FIGS. 14 and 15 of the '919 patent) and the general concept of using a common sequence for RF combining, the specific mechanism of mandating stations to use the foremost 7 bits of the scrambled bit stream of the received MU-RTS frame (which corresponds to the Scrambler Initialization value in the Service Field of an RXVECTOR) as the initial state for their CTS scrambling sequence appears novel in the context of the provided prior art. This specific technical detail ensures inter-operability and successful RF combining in a multi-user response scenario. Without prior art teaching or explicitly suggesting this particular method of deriving a common and synchronized scrambling sequence among multiple stations for RF-combined responses, it cannot be deemed obvious from the given references.

Therefore, without further prior art disclosing this specific scrambling sequence derivation and synchronization for RF-combined multi-user responses, Independent Claim 1 would likely be considered non-obvious.