Prior art — US Patent 11664889

Here are the most relevant prior art references for US Patent 11664889, based on their direct relevance to the claims and the core inventive concepts of the patent. The priority date for US11664889 is December 27, 2006.

Most Relevant Prior Art

1. US20020168993A1 (and its granted patent US6978151B2)

Full Citation: US20020168993A1, "Updating path loss estimation for power control and link adaptation in IEEE 802.11h WLAN" by Koninklijke Philips Electronics N.V.
Publication/Filing Date: Priority Date: May 10, 2001; Publication Date: November 14, 2002.
Brief Description: This patent application describes a method for power control and link adaptation in a wireless local area network (WLAN) operating under IEEE 802.11h. It addresses situations where channel reciprocity is not assumed. The method involves a station (e.g., a mobile terminal) transmitting a "Measurement Pilot" signal. Another station (e.g., an access point) uses this pilot to estimate path loss. This path loss information is then utilized for transmit power control and adaptive link adjustments. The system provides a feedback mechanism to inform the transmitting station of the estimated path loss, enabling it to adjust its power.
Potential Anticipation: This patent significantly anticipates US11664889 by directly addressing the problem of power control when channel reciprocity is absent, a core challenge US11664889 aims to solve in an FDD context.
- Claims 1 & 5 (UE apparatus and method): The concept of a UE transmitting a signal (like the "Measurement Pilot" acting as a UL_Beacon) for channel estimation (path loss) to enable power control is present. The implicit adjustment of transmit power based on feedback from the network is also covered. However, it does not explicitly detail the "power control bits for a plurality of UEs" within a single control message on a downlink physical control channel in a first time slot that also includes a downlink shared channel, nor the precise "second time slot" for the uplink control signal.
- Claims 9 & 13 (Base Station apparatus and method): The base station (access point) receiving a signal (Measurement Pilot) from the UE to estimate path loss and utilizing this for power control feedback is described.
The fundamental principle of using explicit channel sounding (UL_Beacon equivalent) for feedback-based power control in non-reciprocal channels is strongly anticipated.

2. GB2417167A

Full Citation: GB2417167A, "Combining user equipment specific information for multiple users and transmitting in a single communications channel" by Ipwireless Inc.
Publication/Filing Date: Priority Date: August 13, 2004; Publication Date: February 15, 2006.
Brief Description: This patent discloses a cellular communication system and method where a base station efficiently combines control information for multiple user equipments (UEs) into a single, common downlink control channel (referred to as a Low-latency Common Control Channel or LCCCH). This control information can include uplink power control commands, scheduling grants, and rate information. UEs monitor this common channel to extract their individual control parameters, enabling efficient signaling and reduced overhead, especially in systems with a large number of users.
Potential Anticipation: This patent is highly relevant as it directly anticipates key aspects of how power control information is conveyed in US11664889.
- Claims 1 & 5 (UE apparatus and method): This patent directly anticipates the element of "receiving a control message over a physical control channel in a first time slot, wherein the control message has power control bits for a plurality of UEs, wherein the plurality of UEs include the first UE. The UE is further configured to extract power control information for the first UE from the control message." The concept of a "first time slot" for such a downlink channel is standard.
- Claims 9 & 13 (Base Station apparatus and method): This patent directly anticipates the element of "transmitting a control message over a physical control channel in a first time slot, wherein the control message has power control bits for a plurality of user equipments (UEs)."
GB2417167A provides strong anticipation for the mechanism of aggregating and broadcasting power control commands for multiple UEs on a shared downlink control channel (the PLCCH of US11664889). The primary distinguishing features of US11664889 lie in the dedicated uplink control channel (UL_Beacon) in a separate second time slot, its explicit separation from uplink data, and the specific context of evolving TDD systems to FDD by substituting for lost channel reciprocity.

3. US5265119A

Full Citation: US5265119A, "Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system" by Qualcomm Incorporated.
Publication/Filing Date: Priority Date: November 7, 1989; Publication Date: November 23, 1993.
Brief Description: This is a seminal patent for closed-loop power control in Code Division Multiple Access (CDMA) cellular systems. It describes a method where a base station continuously monitors the signal strength from mobile stations. If a mobile station's signal is too strong or too weak, the base station sends a fast power adjustment command (e.g., a single "up" or "down" bit) to that mobile station. The mobile station then adjusts its transmit power level accordingly to maintain optimal signal reception at the base station, thereby mitigating the near-far problem and managing interference.
Potential Anticipation: This patent establishes the fundamental concept of closed-loop uplink power control, which is an underlying principle for US11664889.
- Claims 1, 5 (UE apparatus and method): The core idea of a UE receiving power control information and adjusting its transmit power based on that information is anticipated. However, it lacks the specific channel structures (e.g., dedicated uplink control channel in a second time slot, and aggregated power control bits for multiple UEs in a single control message on a shared downlink channel in a first time slot).
- Claims 9, 13 (Base Station apparatus and method): The base station transmitting power control commands and receiving signals from UEs whose power is adjusted based on these commands is fully anticipated.
While foundational for power control, it predates and does not specify the advanced channel multiplexing, time slot arrangements, and the specific context of adapting TDD-designed systems to FDD by compensating for lost channel reciprocity, which are key aspects of US11664889.

4. US20030069020A1

Full Citation: US20030069020A1, "System and method for physical shared channel allocation in a wireless communication system" by Ipwireless, Inc.
Publication/Filing Date: Priority Date: July 6, 2001; Publication Date: April 10, 2003.
Brief Description: This patent describes a system and method for dynamic allocation of physical shared channels in a wireless communication system, specifically a TD-CDMA system. It details how resources, such as time slots and spreading codes, are allocated to multiple user equipments (UEs) for both uplink and downlink data transmission over shared channels. The invention focuses on providing flexibility and efficiency in resource utilization through shared access.
Potential Anticipation: This patent establishes the context of shared channels and dynamic resource allocation within a TD-CDMA framework, relevant to several elements of US11664889.
- Claims 1 & 5 (UE apparatus and method): The general concept of receiving information over a "downlink shared channel" is present.
- Claims 3 & 7 (UE apparatus and method): Mentions "transmitting data over a physical shared channel in a third time slot."
- Claims 9 & 13 (Base Station apparatus and method): Mentions "transmit data over a downlink shared channel in the first time slot" and "receive data over a physical shared channel in a third time slot."
While it provides a framework for shared channels and time slot usage, it does not explicitly describe the dedicated physical control channels (UL_Beacon, PLCCH) for closed-loop power control, nor the aggregation of power control bits for multiple UEs in a single control message, which are central to US11664889's specific power control mechanism for FDD adaptation.