KR20120055552A - Methods and apparatus for wireless communication - Google Patents

Abstract

One method of wireless communication includes confirming that an anchor base station has received a handover indication signal. Another method includes receiving offset signals from base stations in an active set identifying respective time differences between a reference time and respective times the base station has received a ranging signal from a mobile station; And transmitting the ranging control signal to the mobile station in response to the respective offset signals. Another method includes transmitting to the mobile station a system configuration information signal comprising system configuration information of a base station in the active set in response to the active set signal. Another method includes determining an uplink control channel power parameter in response to channel condition signals received from base stations in the active set. Another method includes transmitting a control signal on base stations in an active set on respective control channels. Devices are also disclosed.

Description

METHODS AND APPARATUS FOR WIRELESS COMMUNICATION}

Cross-Reference to Related Applications

This application claims the benefit of US Provisional Application No. 61 / 223,162, filed Jul. 6, 2009, which is hereby incorporated by reference in its entirety.

This application is a partial continuing application of a formal application resulting from the conversion under 37 CFR§1.53 (c) (3) of U.S. Provisional Application No. 61 / 223,162, filed Jul. 6, 2009; Which claims the benefit of US Provisional Application No. 61 / 078,505, filed Jul. 7, 2008, which is hereby incorporated by reference in its entirety.

[0001]

TECHNICAL FIELD The present invention generally relates to wireless communications, and in particular, to methods and apparatus related to handovers in wireless communications.

IEEE Standard for Local Area and Urban Area Networks, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1 dated February 28, 2006 ("IEEE 802.16e standard") defined various standards for broadband wireless access systems, the entirety of which is incorporated herein by reference. For example, the IEEE 802.16e standard has defined various protocols for handing over a mobile station from an anchor base station to a target base station. Considerations when a mobile station will perform a handover procedure from an anchor base station to a target base station are outside the scope of the IEEE 802.16e standard, but in general, the mobile station communicates with the anchor base station for a period of time, and then from the anchor base station to the target base station. The mobile station will then initiate, for example, the mobile station instead of communicating with the target base station when the mobile station has moved to a location where communication with the target base station is more effective than communication with the anchor base station.

The IEEE 802.16e standard has several disadvantages. For example, before a mobile station can complete a handover to a target base station, the mobile station needs certain system configuration information (SCI) for the target base station, and transmits the system configuration information of such target base station to the mobile station. The protocols defined by the IEEE 802.16e standard for this can be cumbersome and can cause undesirable delays during handover. In addition, the mobile station typically transmits various medium access control (MAC) messages (also referred to simply as "control messages") to initiate the handover procedure, but the IEEE 802.16e standard is expected target base stations for handover. It does not include a satisfactory protocol to facilitate the receipt of such MAC messages at various base stations. In addition, before the mobile station can complete the handover to the target base station, the mobile station can preferably obtain data indicative of the distance between the mobile station and the target base station, so that the mobile station is allocated time for uplink signals from the base station. To transmit the uplink signals at times calculated to cause the uplink signals to be received at the target base station, thus preventing interference with uplink signals from other mobile stations. However, the protocols defined by the IEEE 802.16e standard for acquiring such data can be cumbersome and cause unnecessary delays during handover. Moreover, the IEEE 802.16e standard does not define an acknowledgment by the anchor base station of an indication by the mobile station that the mobile station will perform a handover from the anchor base station to the target base station. Thus, if the anchor base station does not receive an indication or incorrectly receives an indication, the anchor base station may continue to attempt to communicate with the base station after the base station completes the handover to the target base station, which is unnecessary interference and congestion. May cause. Also, if the anchor base station does not receive an indication, the anchor base station may not have informed the target base station that the mobile station will perform a handover to the target base station, in which case the target base station may not be ready to communicate with the mobile station. And a communication interruption may occur.

According to one exemplary embodiment, a method is provided for facilitating handover of a mobile station from an anchor base station to a target base station. The method includes receiving, at the anchor base station, a handover indication signal from the mobile station indicating that the mobile station will perform a handover from the anchor base station to the target base station; And transmitting an acknowledgment signal to the mobile station confirming that the anchor base station has received the handover indication signal.

According to another exemplary embodiment, an interface for facilitating wireless communication with a mobile station; And a processor in communication with the interface. The processor receives from the interface a handover indication signal from the mobile station indicating that the mobile station will perform a handover from the base station apparatus to a target base station; And enable the interface to transmit an acknowledgment signal to the mobile station confirming that the base station apparatus has received the handover indication signal.

According to another exemplary embodiment, a base station apparatus, comprising: means for receiving, from a mobile station, a handover indication signal indicating that the mobile station will perform a handover from the base station apparatus to a target base station; And means for transmitting an acknowledgment signal to the mobile station confirming that the base station apparatus has received the handover indication signal.

According to another exemplary embodiment, a method is provided that facilitates a mobile station in wireless communication with an anchor base station to obtain data indicative of distances between the mobile stations and base stations in an active set of base stations in wireless communication with the mobile station. The active set includes a subset of neighbor base stations of the anchor base station. The method includes transmitting from the anchor base station to each other base station of the active set a ranging resource signal identifying a reference code and a reference time associated with the mobile station; Cause the mobile station to transmit a ranging signal containing the reference code to each base station of the active set at a predetermined time in response to the reference time, so that each base station of the active set has the ranging at each time Receiving a signal; Receiving, from each base station of the active set, a respective offset signal identifying a respective time difference between the reference time and each respective time that the base station of the active set has received the ranging signal; And transmitting a ranging control signal to the mobile station in response to the respective offset signals.

The method may further comprise generating the reference code from pseudo-randomly generated code.

The transmitting of the ranging control signal may include transmitting a ranging control signal representing an average of the respective time differences between the reference time and each of the respective times when the base station of the active set receives the ranging signal. It may include the step.

Transmitting the ranging control signal includes transmitting a plurality of ranging control signals, each of the plurality of ranging control signals associated with each base station of the active set, the reference time and the The base station of the active set may represent the respective time difference between the respective times of receiving the ranging signal.

The active set may further include the anchor base station.

According to another exemplary embodiment, a base station apparatus, comprising: a first interface for facilitating wireless communication with a mobile station; A second interface for facilitating communication with at least one neighboring base station in an active set in wireless communication with the mobile station; And a processor in communication with the first interface and the second interface. The processor to cause the second interface to transmit a ranging resource signal identifying a reference code and a reference time associated with the mobile station to the at least one neighboring base station in the active set; Sending a ranging command signal to the mobile station instructing the mobile station to transmit a ranging signal containing the reference code to each base station in the active set at a predetermined time in response to the reference time; Let each base station in the active set receive the ranging signal at a respective time; Receive each offset signal from each neighbor base station in the active set from the second interface, each offset signal being the reference time and each of the neighbor base stations in the active set receiving the ranging signal; Identifying each time difference between times; And operable to cause the first interface to transmit a ranging control signal to the mobile station in response to each of the respective offset signals.

The processor may be further operable to generate the reference code from a pseudo random generated code.

The ranging control signal may represent an average of each of the respective time differences between the reference time and each respective time at which each base station in the active set receives the ranging signal.

The ranging control signal includes a plurality of ranging control signals, each of the plurality of ranging control signals associated with each of the base stations of the active set, wherein the reference time and each of the base stations The respective time difference between the respective times of receiving the signal may be represented.

The active set may further comprise the apparatus, the processor to receive the ranging signal from the mobile station from the first interface; Calculate a time difference between the reference time and the time the device receives the ranging signal from the mobile station; Further enable the first interface to transmit the ranging control signal to the mobile station in response to the time difference between the reference time and the time the device receives the ranging signal from the mobile station. Can be.

According to another exemplary embodiment, there is provided a base station apparatus configured to wirelessly communicate with a mobile station and configured to communicate with at least one neighboring base station in an active set that is in wireless communication with the mobile station. The apparatus includes means for transmitting a ranging resource signal identifying a reference code and a reference time associated with the mobile station to the at least one neighboring base station in the active set; Transmitting a ranging command signal to the mobile station instructing the mobile station to transmit a ranging signal including the reference code to each base station in the active set at a predetermined time in response to the reference time, respectively. Means for causing a base station of to receive the ranging signal at each time; Means for receiving a respective offset signal from each base station in the active set, each offset signal being each between the reference time and each time the base station in the active set received the ranging signal. Identifying a time difference; And means for transmitting a ranging control signal to the mobile station in response to each of the respective offset signals.

According to another exemplary embodiment, a method of distributing system configuration information of a base station is provided. The method includes receiving from a first mobile station having a first active set of base stations, a first active set signal indicating that the first mobile station has added the base station to the first active set; And in response to receiving the first active set signal, transmitting a system configuration information signal comprising the system configuration information of the base station to the first mobile station.

The system configuration information of the base station includes an identifier of the base station; An identifier of the preamble index of the base station; An identifier of a subchannel index of the base station; Frequency allocation information for the base station; A time / frequency synchronization indicator associated with the base station; Uplink channel information for the base station; Downlink channel information for the base station; A trigger reference indicator associated with the base station; Equivalent isotropic radiated power of the base station; Handover information for the base station; Scheduling service information for the base station; Supported mobility feature information for the base station; A paging group identifier associated with the base station; An identifier of the channel bandwidth of the base station; An identifier of a cyclic prefix of the base station; An identifier of a frame duration of the base station; An identifier of a fast Fourier transform size of the base station; And one or more information in a group consisting of an operation mode of starting subchannelization of a frame and channel number of the base station.

The method may further comprise receiving, from a second mobile station having a second active set of base stations, a second active set signal indicating that the second mobile station has added the base station to the second active set. . Transmitting the system configuration information signal to the first mobile station includes multicasting the system configuration information signal to the first mobile station and the second mobile station in response to receiving a first indicator signal and a second indicator signal. can do.

According to another exemplary embodiment, a base station apparatus, comprising: an interface for facilitating wireless communication with a first mobile station having a first active set of base stations; Computer readable memory having a storage for storing system configuration information of a plurality of base stations; And a processor in communication with the interface and the computer readable memory. The processor receives from the interface a first active set signal from the first mobile station indicating that the first mobile station has added one of the plurality of base stations to the first active set; Enable the interface to transmit a system configuration information signal to the first mobile station, the system configuration information signal comprising system configuration information of the one of the plurality of base stations in response to receiving the first active set signal. do.

The system configuration information of the base station includes an identifier of the base station; An identifier of the preamble index of the base station; An identifier of a subchannel index of the base station; Frequency allocation information for the base station; A time / frequency synchronization indicator associated with the base station; Uplink channel information for the base station; Downlink channel information for the base station; A trigger reference indicator associated with the base station; Equivalent isotropic radiated power of the base station; Handover information for the base station; Scheduling service information for the base station; Supported mobility feature information for the base station; A paging group identifier associated with the base station; An identifier of the channel bandwidth of the base station; An identifier of a cyclic prefix of the base station; An identifier of a frame duration of the base station; An identifier of a fast Fourier transform size of the base station; And one or more information in a group consisting of an operation mode of starting subchannelization of a frame and channel number of the base station.

The processor is further configured to interface the second active set signal from the second mobile station indicating that a second mobile station having a second active set of base stations added the one of the plurality of base stations to the second active set. And may be configured to be more operable to receive from. The processor may be further operable to cause the interface to multicast the system configuration information to the first and second mobile stations in response to receiving a first indicator signal and a second indicator signal.

According to another exemplary embodiment, a base station apparatus, comprising: means for storing system configuration information of a plurality of base stations; Means for receiving an active set signal from a mobile station having an active set indicating that the mobile station has added one base station of the plurality of base stations to the active set; And means for transmitting to the mobile station a system configuration information signal comprising the system configuration information of the one of the plurality of base stations in response to receiving the active set signal.

According to another exemplary embodiment, a method is provided for controlling a mobile station in wireless communication with a plurality of base stations via an uplink control channel. The method comprises receiving a respective channel condition signal from each base station of the plurality of base stations, wherein each channel condition signal is received from the mobile station via the uplink control channel at one base station of the plurality of base stations. Indicating a channel condition of each of the signals; Determining an uplink control channel power parameter in response to the respective channel condition signals; And transmitting to the mobile station a power control signal comprising the uplink control channel power parameter.

Each of the channel conditions may comprise a signal to noise ratio.

Determining the uplink control channel power parameter comprises a threshold signal to noise ratio and a signal to noise ratio of each of the control signals received from the mobile station via the uplink control channel at each base station of the plurality of base stations. Determining the ratio of the lowest ratio among these may include.

According to another exemplary embodiment, a base station apparatus, comprising: a first interface for facilitating wireless communication with a mobile station; A second interface for facilitating communication with at least one neighboring base station in an active set in wireless communication with the mobile station; And a processor in communication with the first interface and the second interface. The processor receives a respective channel condition signal from each of the neighbor base stations of the active set from the second interface, each channel condition signal from the mobile station through an uplink control channel at the neighbor base station of the active set; Indicate a channel condition of each of the received control signals; Channel conditions of control signals received from the mobile station via the uplink control channel in the apparatus; And determine an uplink control channel power parameter in response to respective channel condition signals received from the at least one neighbor base station of the active set; Operatively configured to cause the first interface to transmit a power control signal including the uplink control channel power parameter to the mobile station.

Each of the channel conditions may comprise a signal to noise ratio.

The processor further comprises a threshold signal to noise ratio and a signal to noise ratio of control signals received from the mobile station via the uplink control channel at the apparatus; And determine, at each neighboring base station of the active set, the uplink control channel power parameter in response to the ratio of the lowest of the respective signal to noise ratios of the control signals received from the mobile station over the uplink control channel. It can be configured to be operable.

According to another exemplary embodiment, there is provided a base station apparatus configured to wirelessly communicate with a mobile station and configured to communicate with at least one neighboring base station in an active set that is in wireless communication with the mobile station. The apparatus means for receiving respective channel condition signals from each neighboring base station of the active set, wherein each channel condition signal is received from the mobile station via an uplink control channel at the neighboring base station of the active set; Indicating a channel condition of each of the signals; Channel conditions of control signals received from the mobile station via the uplink control channel in the apparatus; And means for determining an uplink control channel power parameter in response to respective channel condition signals received from the at least one neighboring base station of the active set. And means for transmitting to the mobile station a power control signal comprising the uplink control channel power parameter.

According to another exemplary embodiment, a method is provided for transmitting a control signal to a plurality of base stations in an active set of mobile stations. The method includes transmitting, for each base station in the active set, the control signal to the base station on each control channel.

According to another exemplary embodiment, a mobile station apparatus, comprising: an interface for facilitating wireless communication with a plurality of base stations in an active set of the apparatus; And a processor in communication with the interface and operatively configured to transmit a control signal on each control channel to each base station in the active set.

According to another exemplary embodiment, a mobile station apparatus, comprising: means for facilitating wireless communication with a plurality of base stations in an active set of the apparatus; And means for transmitting a control signal on each control channel to each base station in the active set.

Other aspects and features of the present invention will become apparent to those skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying drawings.

Hereinafter, embodiments of the present application are described by way of example only with reference to the accompanying drawings, in which:
1 is a block diagram of an exemplary cellular communication system,
2 is a block diagram of the exemplary base station shown in FIG. 1,
3 is a block diagram of the exemplary mobile station shown in FIG. 1;
4 is a block diagram of the exemplary relay station shown in FIG. 1;
5 is a block diagram of a logical specification of an exemplary OFDM transmitter of the base station of FIG. 2;
6 is a block diagram of a logical specification of an exemplary OFDM receiver of the wireless terminal of FIG. 3;
7 is a schematic diagram of a network architecture implemented by the cellular communication system of FIG. 1, corresponding to FIG. 1 of IEEE 802.16m-08 / 003r1;
8 is a schematic diagram of the architecture of the relay station of FIG. 4 and corresponds to FIG. 2 of IEEE 802.16m-08 / 003r1;
9 is a schematic diagram of a system reference model of the cellular communication system of FIG. 1, corresponding to FIG. 3 of IEEE 802.16m-08 / 003r1;
10 is a schematic diagram of a protocol structure according to IEEE 802.16m, corresponding to FIG. 4 of IEEE 802.16m-08 / 003r1;
FIG. 11 is a flowchart of processing of an MS / BS data plane according to IEEE 802.16m, and corresponds to FIG. 5 of IEEE 802.16m-08 / 003r1;
12 is a processing flowchart of the MS / BS control plane according to IEEE 802.16m, which corresponds to FIG. 6 of IEEE 802.16m-08 / 003r1;
FIG. 13 is a schematic diagram of a protocol architecture for supporting a multicarrier system, corresponding to FIG. 7 of IEEE 802.16m-08 / 003r1;
14 is a schematic diagram of an exemplary control system of the base station of FIG. 2;
15 is a schematic diagram of an exemplary control system of the mobile station of FIG. 3;
FIG. 16 is a schematic diagram of an exemplary preamble index message sent by the base station control system of FIG. 14;
FIG. 17 is a schematic diagram of an exemplary active set message sent by the mobile station control system of FIG. 15;
18 is a block diagram of exemplary system configuration information distribution codes executed by a microprocessor of the base station control system of FIG. 14;
19 is a schematic diagram of an example system control information message sent by the base station control system of FIG. 14;
20 is a block diagram of example power control codes executed by the microprocessor of FIG. 14,
21 is a schematic diagram of an example channel condition request message sent by the base station control system of FIG. 14;
22 is a schematic diagram of an example channel condition message sent by the base station control system of FIG. 14;
FIG. 23 is a schematic diagram of an example power control message sent by the base station control system of FIG. 14;
FIG. 24 is a block diagram of example control assignment codes executed by the microprocessor of FIG. 14;
25 is a schematic diagram of an exemplary control channel assignment message sent by the base station control system of FIG. 14;
FIG. 26 is a block diagram of example uplink control codes executed by the microprocessor of FIG. 15;
FIG. 27 is a block diagram of example ranging initiation codes executed by the microprocessor of FIG. 14;
28 is a schematic diagram of an exemplary ranging resource message sent by the base station control system of FIG. 14;
FIG. 29 is a schematic diagram of an exemplary ranging command message sent by the base station control system of FIG. 14;
30 is a block diagram of exemplary ranging codes executed by the microprocessor of FIG. 15, and FIG.
FIG. 31 is a schematic diagram of an exemplary offset message sent by the base station control system of FIG. 14;
FIG. 32 is a schematic diagram of an exemplary single ranging parameter ranging control message sent by the base station control system of FIG. 14;
33 is a schematic diagram of an exemplary multiple ranging parameter ranging control message sent by the base station control system of FIG. 14;
34 is a block diagram of example handover codes executed by the microprocessor of FIG. 15, and FIG.
FIG. 35 is a schematic diagram of an example handover indication message sent by the mobile station control system of FIG. 15;
36 is a block diagram of example handover acknowledgment responder codes executed by the microprocessor of FIG. 14;
FIG. 37 is a schematic diagram of an exemplary handover acknowledgment message sent by the base station control system of FIG. 14.
In the different figures the same reference numbers are used to indicate similar elements.

Wireless system overview

Referring to the drawings, FIG. 1 shows a plurality of cells 121, 123, 124, 125, 127, 128 respectively serviced by corresponding base stations (BS) 141, 143, 144, 145, 147, 148, 149. 129 is a base station controller (BSC) 10 that controls wireless communications. In some configurations, each cell is further divided into a number of sectors 13 or zones (not shown). In general, each base station 141, 143, 144, 145, 147, 148, 149 is a mobile station MS within one of the corresponding cells 121, 123, 124, 125, 127, 128, 129 and And / or facilitate communications using an orthogonal frequency division multiplexing (OFDM) digital modulation scheme with wireless terminals 161, 162, 163, 164, 165.

The movement of mobile stations 161, 162, 163, 164, 165 relative to base stations 141, 143, 144, 145, 147, 148, 149 causes large fluctuations in channel conditions. As shown, the base stations 141, 143, 144, 145, 147, 148, 149 and mobile stations 161, 162, 163, 164, 165 are multiple antennas for providing spatial diversity for communications. It may include. In some configurations, relay stations 15 may assist communications between base stations 141, 143, 144, 145, 147, 148, 149 and mobile stations 161, 162, 163, 164, 165. . Mobile stations 161, 162, 163, 164, 165 are cells 121, 123, 124, 125, 127, 128, 129, sectors 13, zones (not shown), base stations 141, 143. Cells 124, 145, 147, 148, 149 or relay stations 15 from cells 121, 123, 124, 125, 127, 128, 129, sectors 13, zones (not shown) May be handed off to one of the base stations 141, 143, 144, 145, 147, 148, 149 or the relay stations 15. In some configurations, the base stations 141, 143, 144, 145, 147, 148, 149 communicate with each other and with another network (such as a core network or the Internet, not shown, all over) and backhaul network 11. In some configurations, the base station controller 10 is not necessary.

Base station

Referring to FIG. 2, a base station 141 is shown, and base stations 143, 144, 145, 147, 148, 149 are substantially the same as base station 141. Base station 141 generally includes control system 20, baseband processor 22, transmit circuitry 24, receive circuitry 26, multiple transmit antennas 28, and network interface 30. Receiving circuit 26 is one or more provided by mobile stations 161, 162, 163, 164, 165 (mobile station 161 is shown in FIG. 3) and relay stations 15 (shown in FIG. 4). Receive radio frequency signals with information from remote transmitters. A low noise amplifier and a filter (not shown) can work together to amplify the received signal for processing and to remove broadband interference from the received signal. The down conversion and digitization circuitry (not shown) will then down convert the filtered received signal into an intermediate or baseband frequency signal and then digitize it into one or more digital streams.

The baseband processor 22 processes the digitized received signal to extract the information or data bits carried in the received signal. Such processing typically includes demodulation, decoding, and error correction operations. Thus, baseband processor 22 is typically implemented within one or more digital signal processors (DSPs) or application specific integrated circuits (ASICs). The information is then transmitted across the wireless network via the network interface 30, or the mobile stations 161, 162, serviced by one or more of the base stations 141, 143, 144, 145, 147, 148, 149. 163, 164, 165, either directly or with the help of one of the relay stations 15. Thus, network interface 30 facilitates communication with, for example, base stations 143, 144, 145, 147, 148, 149.

In order to perform the transmission functions, the baseband processor 22 receives digitized data, which may represent voice, data or control information, from the network interface 30 under the control of the control system 20 and is encoded for transmission. Generate data. The encoded data is output to the transmitting circuit 24 where it is modulated by one or more carrier signals having the desired transmission frequency or frequencies. A power amplifier (not shown) amplifies the modulated carrier signals to a level suitable for transmission and delivers the modulated carrier signals to antennas 28 through a matching network (not shown). Thus, antennas 28 function as an interface to facilitate wireless communication with one or more of mobile stations 161, 162, 163, 164, 165. Modulation and processing details are described in more detail below.

Referring to FIG. 14, a control system 20 is schematically shown. In the illustrated embodiment, the control system 20 includes a microprocessor 170, all of which includes a program memory 172, a data memory 174, and a clock 176 in communication with the microprocessor 170. . The microprocessor 170 also includes a baseband processor interface 178 for communicating with the baseband processor 22 (shown in FIG. 2). Thus, in the illustrated embodiment, the control system 20 is shown in FIG. 1 via the baseband processor interface 178, through the baseband processor 22 and via the antennas 28 or the network interface 30. Communicate with other base stations and mobile stations. In the illustrated embodiment, program memory 172 is a known computer readable memory and generally includes codes for instructing microprocessor 170 to perform various functions of control system 20. Data memory 174 is also generally known computer readable memory for storing data related to the functions of control system 20. Clock 176 stores the current time value and is synchronized with the corresponding clocks of base stations 143, 144, 145, 147, 148, 149 in the illustrated embodiment. Control system 20 is shown to include a microprocessor 170, program memory 172, data memory 174, and clock 176 in the illustrated embodiment, although those skilled in the art will appreciate that alternative embodiments are different. It will be appreciated that it may include different combinations of components or components.

Mobile station

Referring to FIG. 3, a mobile station 161 is shown, with the mobile stations 162, 163, 164, and 165 being substantially the same as the mobile station 161. In FIG. Similar to the base station 141, the mobile station 161 may include a control system 32, a baseband processor 34, a transmit circuit 36, a receive circuit 38, a plurality of receive antennas 40 and user interface circuits ( 42). The receiving circuit 38 receives radio frequency signals with information from one or more of the base stations 141, 143, 144, 145, 147, 148, 149 and the relay stations 15. A low noise amplifier and filter (not shown) can work together to amplify the signal for processing and to remove broadband interference from the signal. The down conversion and digitization circuitry (not shown) will then down convert the filtered received signal into an intermediate or baseband frequency signal and then digitize it into one or more digital streams.

Baseband processor 34 processes the digitized signal to extract the information or data bits carried in the signal. Such processing typically includes demodulation, decoding, and error correction operations. Baseband processor 34 is generally implemented within one or more digital signal processors (DSPs) and application specific integrated circuits (ASICs).

For transmission, baseband processor 34 receives digitized data, which may represent voice, video, data or control information, from control system 32 and encodes for transmission. The encoded data is output to the transmitting circuit 36 where it is used by the modulator to modulate one or more carrier signals at the desired transmission frequency or frequencies. A power amplifier (not shown) amplifies the modulated carrier signals to a level suitable for transmission and forwards the modulated carrier signal to receive antennas 40 through a matching network (not shown). Various modulation and processing techniques available to those skilled in the art include direct or relay stations between mobile stations 161, 162, 163, 164, 165 and base stations 141, 143, 144, 145, 147, 148, 149. It can be used for signal transmission through the field (15). Thus, antennas 40 serve as an interface to facilitate wireless communication with one or more of base stations 141, 143, 144, 145, 147, 148, 149.

Referring to FIG. 15, a control system 32 is schematically shown. The control system 32 includes a microprocessor 180 and includes a program memory 182, a data memory 184, and a clock 186, all in communication with the microprocessor 180. Microprocessor 180 also includes a baseband processor interface port 188 for communicating with baseband processor 34 (shown in FIG. 3). Thus, in the illustrated embodiment, the control system 32 communicates with the base stations shown in FIG. 1 via the baseband processor interface 188, through the baseband processor 34 and via the antennas 40. . In the illustrated embodiment, program memory 182 is a known computer readable memory and generally stores codes for instructing microprocessor 180 to perform the various functions of control system 32. Data memory 184 is also generally known computer readable memory for storing data related to the functions of control system 32. Clock 186 stores a value representing the current time and, in the illustrated embodiment, the corresponding clocks of mobile stations 162, 163, 164, and 165 and the clock (shown in FIG. 14) of base station 141. 176 and corresponding clocks of base stations 143, 144, 145, 147, 148, 149. Control system 32 is shown to include microprocessor 180, program memory 182, data memory 184 and clock 186 in the illustrated embodiment, although those skilled in the art will appreciate that alternative embodiments It will be appreciated that it may include different combinations of components or components.

OFDM  Modulation

In OFDM modulation, the transmission band is divided into a number of orthogonal carrier waves. Each carrier wave is modulated according to the digital data to be transmitted. Since OFDM divides the transmission band into multiple carriers, the bandwidth per carrier decreases and the modulation time per carrier increases. Since multiple carriers are transmitted in parallel, the transmission rate of digital data or symbols on any given carrier is lower than when a single carrier is used.

OFDM modulation involves the use of fast Fourier inverse transform (IFFT) on the information to be transmitted. For demodulation, fast Fourier transform (FFT) is performed on the received signal to recover the transmitted information. In practice, IFFT and FFT are provided by digital signal processing, which includes discrete Fourier inverse transform (IDFT) and discrete Fourier transform (DFT), respectively. Thus, a feature of OFDM modulation is that orthogonal carrier waves are generated for multiple bands in a transmission channel. Modulated signals are digital signals that can stay within their respective bands with a relatively low transmission rate. Individual carrier waves are not directly modulated by digital signals. Instead, all carrier waves are modulated at once by the IFFT process.

In operation, OFDM is preferably used for downlink transmission from at least base stations 141, 143, 144, 145, 147, 148, 149 to mobile stations 161, 162, 163, 164, 165. Each base station 141, 143, 144, 145, 147, 148, 149 has " n " transmit antennas 28 (n > = 1), and each mobile station 161, 162, 163, 164, 165 has "m" receive antennas 40 (m> = 1). In particular, each antenna can be used for reception and transmission using appropriate duplexers or switches, and so labeled only for clarity.

When relay stations 15 are used, OFDM is preferably from base stations 141, 143, 144, 145, 147, 148, 149 to relay stations and from relay stations 161, 162, 163, 164. 165 is used for downlink transmission.

Relay station

4, an example of the relay station 15 is shown. Similar to base station 141 and mobile station 161, relay station 15 may include control system 132, baseband processor 134, transmit circuitry 136, receive circuitry 138, multiple antennas 130, and The relay circuit 142 is included. The relay circuit 142 allows the relay station 15 to communicate between one of the base stations 141, 143, 144, 145, 147, 148, 149 and one of the mobile stations 161, 162, 163, 164, 165. Enable to apply. The receiving circuit 138 receives radio frequency signals with information from one or more base stations 141, 143, 144, 145, 147, 148, 149 and mobile stations 161, 162, 163, 164, 165. A low noise amplifier and a filter (not shown) can work together to amplify the signal for processing and to remove broadband interference from the signal. The down conversion and digitization circuitry (not shown) will then down convert the filtered received signal into an intermediate or baseband frequency signal and then digitize it into one or more digital streams.

The baseband processor 134 processes the digital streams to extract the information or data bits carried in the signal. Such processing typically includes demodulation, decoding, and error correction operations. Baseband processor 134 is typically implemented within one or more digital signal processors (DSPs) and application specific integrated circuits (ASICs).

For transmission, the baseband processor 134 receives from the control system 132 digitized data, which may represent voice, video, data or control information, and encodes for transmission. The encoded data is output to the transmitting circuit 136 where it is used by the modulator to modulate one or more carrier signals at the desired transmission frequency or frequencies. A power amplifier (not shown) amplifies the modulated carrier signals to a level suitable for transmission, and delivers the modulated carrier signal to the antennas 130 through a matching network (not shown). As noted above, various modulation and processing techniques available to those skilled in the art are between mobile stations 161, 162, 163, 164, 165 and base stations 141, 143, 144, 145, 147, 148, 149. It may be used for direct signal transmission at or indirect signal transmission through relay stations 15.

OFDM  send

Referring to FIG. 5, a logical OFDM transmission architecture is described. Referring to FIG. 1, the base station controller 10 first transmits data to be transmitted to various mobile stations 161, 162, 163, 164, and 165 to the base stations 141, 143, 144, 145, 147, 148, and 149. It will transmit directly or with the help of one of the relay stations 15. Base stations 141, 143, 144, 145, 147, 148, 149 use channel quality indicators (CQIs) associated with mobile stations 161, 162, 163, 164, 165 to schedule data for transmission and The appropriate coding and modulation may be selected for the transmission of the scheduled data. CQIs may be provided directly by the mobile stations 161, 162, 163, 164, 165, or may be determined by the base stations 141, 143, 144, 145, 147, 148, 149 based on the information provided by the mobile stations. Can be. In either case, the CQI for each mobile station 161, 162, 163, 164, 165 is a function of the extent to which the channel amplitude (or response) varies over the OFDM frequency band.

Scheduled  Transfer of data to mobile stations

1 and 5, the scheduled data 44 is a stream of bits, which is scrambled in a manner that reduces the peak to average power ratio associated with the data using the data scrambling logic 46. Cyclic redundancy check (CRC) for scrambled data is determined using CRC addition logic 48 and appended to the scrambled data. Channel coding is then performed using the channel encoder 50 to effectively add redundancy to the data, thereby facilitating recovery and error correction at the mobile stations 161, 162, 163, 164, 165. The channel coding for a particular mobile station among mobile stations 161, 162, 163, 164, 165 is based on the CQI associated with that particular mobile station. In some implementations, channel encoder 50 uses known turbo encoding techniques. The encoded data is then processed by rate matching logic 52 to compensate for data expansion associated with the encoding.

Bit interleaver logic 54 systematically rearranges the bits in the encoded data to minimize the loss of consecutive data bits. The rearranged data bits are systematically mapped by mapping logic 56 to corresponding symbols in accordance with the selected baseband modulation. Preferably, quadrature amplitude modulation (QAM) or quadrature phase shift key (QPSK) modulation is used. The degree of modulation is preferably selected based on the CQI associated with the particular mobile station. The symbols may be systematically rearranged using symbol interleaver logic 58 to further enhance the immunity of the transmitted data to periodic data loss caused by frequency selective fading.

At this point, the groups of bits have been mapped to symbols representing locations in the amplitude and phase constellation. Then, when spatial diversity is required, the blocks of symbols are processed by space-time block code (STC) encoder logic 60, which makes the transmission signals more robust to interference and the mobile stations 161, 162, 163. 164, 165 change the symbols in a way that makes them easier to decode. STC encoder logic 60 processes incoming symbols and provides " n " outputs corresponding to the number of transmit antennas 28 of base stations 141, 143, 144, 145, 147, 148, 149. . The control system 20 and / or baseband processor 22 as described above with respect to FIG. 5 will provide a mapping control signal for controlling the STC encoder. At this point, assume that the symbols for the "n" outputs represent data that can be transmitted and recovered by the mobile stations 161, 162, 163, 164, 165.

In this example, it is assumed that the base station 141 of FIG. 1 has two antennas 28 (n = 2), and the STC encoder logic 60 provides two output streams of symbols. Each of the output streams of symbols is sent to a corresponding output path 61, 63 shown separately for ease of understanding. Those skilled in the art will appreciate that one or more processors may be used to provide such digital signal processing, alone or in conjunction with other processing described herein. In each output path, IFFT processor 62 will act on each of the symbols provided to it to perform Fourier inverse transform. The output of IFFT processor 62 provides the symbols of the time domain. Time domain symbols, also known as OFDM symbols, are grouped into frames by assigning a prefix by prefix insertion function 64. The resulting frame is upconverted to an intermediate frequency in the digital domain and converted into an analog signal via respective digital upconversion (DUC) and digital / analog (D / A) conversion circuitry 66. The resulting (analog) signals from each output path are then simultaneously modulated, amplified, and mobile stations 161, 162, 163, 164 at the desired RF frequency via RF circuit 68 and transmit antennas 28. , 165). In particular, pilot signals known by the intended mobile station among the mobile stations 161, 162, 163, 164, 165 are scattered between the subcarriers. The mobile stations 161, 162, 163, 164, 165, described in detail below, will use pilot signals for channel estimation.

At a mobile station  Reception of signals

Referring now to FIG. 6, transmission by mobile station 161 either directly from one of the base stations (eg, base station 141 of FIG. 1) or with the aid of one of the relay stations (15 of FIG. 1). The reception of the signals is described. Upon arrival of the transmission signals at each of the receive antennas 40 of one of the mobile stations 161, 162, 163, 164, 165, the respective signals are demodulated and amplified by the corresponding RF circuit 70. . For simplicity, only one of the two receive paths is described and shown in detail. Analog-to-digital (A / D) converter and downconversion circuitry 72 digitizes and downconverts the analog signal for digital processing. Automatic gain control circuit (AGC) 74 may use the resulting digitized signal to control the gain of the amplifiers in RF circuit 70 based on the received signal level.

First, a digitized signal is provided to the synchronization logic generally shown at 76, which includes a coarse synchronization function 78, which buffers several OFDM symbols and between two consecutive OFDM symbols. Calculate autocorrelation. The resulting temporal index corresponding to the maximum value of the correlation result determines the detailed synchronization search window, and the detailed synchronization function 80 uses this window to determine the correct framing start position based on the headers. The output of detailed synchronization function 80 facilitates frame acquisition by frame alignment logic 84. Proper framing alignment is important for subsequent FFT processing to provide accurate conversion from the time domain to the frequency domain. The detailed synchronization algorithm is based on the correlation between the received pilot signals carried by the headers and the local copy of the known pilot data. When frame alignment acquisition occurs, the prefix of the OFDM symbol is removed by the prefix removal logic 86, and the resulting samples are sent to the frequency offset / correction function 88, which function is an unmatched local in the transmitter and receiver. Compensates for the system frequency offset caused by oscillators. Preferably, the synchronization logic 76 includes a frequency offset and clock estimation function 82, which assists in estimating the frequency offset and clock offset in the transmission signal using the headers and converting such estimates into frequency offset / correction. Provided to function 88 to properly process OFDM symbols.

At this point, the OFDM symbols in the time domain are ready to be converted into the frequency domain by the FFT processing function 90. The result is a set of frequency domain symbols, which are sent to processing function 92. The processing function 92 extracts the scattered pilot signal using the scattered pilot extraction function 94, determines the channel estimate based on the pilot signal extracted using the channel estimation function 96, and the channel reconstruction function. Use 98 to provide channel responses for all subcarriers. To determine the channel response for each of the subcarriers, the pilot signal is essentially a plurality of pilot symbols scattered between data symbols across OFDM subcarriers in a known pattern in both time and frequency.

Continuing with FIG. 6, processing logic compares the received pilot symbols with the pilot symbols expected at certain subcarriers at predetermined times to determine a channel response for the subcarriers that transmitted the pilot symbols. The results are interpolated to estimate the channel response for most, if not all, of the remaining subcarriers that did not provide pilot symbols. The actual and interpolated channel responses are used to estimate the overall channel response, including the channel responses for most but not all of the subcarriers in the OFDM channel.

Frequency domain symbols and channel reconstruction information derived from the channel responses for each receive path are provided to the STC decoder 100, which provides STC decoding on both receive paths to recover the transmit symbols. The channel reconstruction information provides the STC decoder 100 with equalization information sufficient to remove the effects of the transmission channel when processing each frequency domain symbol.

The recovered symbols are placed in reverse order using symbol deinterleaver logic 102 corresponding to the symbol interleaver logic 58 of the transmitter. The deinterleaved symbols are then demodulated or demapped into the corresponding bitstream using demapping logic 104. The bits are then deinterleaved using bit deinterleaver logic 106 corresponding to bit interleaver logic 54 of the transmitter architecture. The deinterleaved bits are then processed by the rate dematching logic 108 and provided to the channel decoder logic 110 to recover the original scrambled data and the CRC checksum. Thus, CRC logic 112 removes the CRC checksum, examines the scrambled data in a traditional manner, and provides this data to descrambling logic 114, which provides this data with a known base station descrambling code. The data is descrambled to reproduce the original transmission data 116 as data 116.

6, at the same time with restoration of the data 116, enough information is determined to generate the CQI, or at least the CQI at each of the base stations 141, 143, 144, 145, 147, 148, 149, Transmitted to each of the base stations. As mentioned above, CQI may be a function of the carrier to interference ratio (CR) as well as the degree to which the channel response varies across various subcarriers within the OFDM frequency band. In this embodiment, the channel gains for each subcarrier in the OFDM frequency band used to transmit information are compared with each other to determine the extent to which the channel gain varies over the OFDM frequency band. Although various techniques can be used to measure the degree of change, one technique is to calculate the standard deviation of the channel gain for each subcarrier across the OFDM frequency band used to transmit the data.

In some embodiments, relay stations may operate in a time division manner using only one radio, or alternatively include multiple radios.

Active sets

Referring back to FIG. 1, each of the base stations 141, 143, 144, 145, 147, 148, 149 typically has a plurality of neighboring base stations, which are generally base stations with neighboring cells. Referring to FIG. 1 as an example, base station 143 has neighboring base stations 141, 144, 145, 147, 148, 149.

Each of the mobile stations 161, 162, 163, 164, 165 sometimes defines a respective active set of base stations and / or relay stations, and in the illustrated embodiment the respective active sets are the base stations 141, 143, 144,. One or more of 145, 147, 148, 149 and / or one or more of the relay stations 15 under the control of each base station. In the illustrated embodiment, each of these active sets includes an anchor base station, and the mobile station communicates with the anchor base station as described above. In addition, these active sets may include some or all of the neighbor base stations of the anchor base station, or none of them, such that the active set generally includes a subset of the anchor base station and the neighbor base stations of the anchor base station. do. For example, in the illustrated embodiment, the mobile station 161 may have an active set that includes only base stations 141, and the mobile station 162 may have an active set that includes base stations 141, 145. . As another example, neighboring base stations of mobile station 163 may be base stations 141, 143, 145 and one or more relay stations 15, but due to signal propagation conditions or other circumstances, mobile station 163 may not be active. Only base stations 141, 143 may be included in the set. In alternative embodiments, active sets may exclude anchor base stations, but may include some or all of the neighbor base stations and / or one or more relay stations of the anchor base station, or none.

One of the mobile stations 161, 162, 163, 164, 165, for example, when the mobile station is powered on or enters the area defined by the cells 121, 123, 124, 125, 127, 128, 129 When entering one of the cells 121, 123, 124, 125, 127, 128, or 129, the mobile station communicates with one of the base stations 141, 143, 144, 145, 147, 148, 149 within the communication range of the mobile station. Communication is initiated, which in the illustrated embodiment is the initial anchor base station of the mobile station. At this time, the anchor base station transmits information including the preamble indexes of the neighbor base stations of the anchor base station to the mobile station, so that the mobile station can identify each of the neighbor base stations and measure, for example, its signal strengths.

In the illustrated embodiment, the anchor base station transmits the preamble indexes of each of its neighbor base stations to the mobile station using a preamble index message (190 as described below). Referring to FIG. 1 as an example, the base station 143 transmits the preamble indexes of its neighbor base stations 141, 144, 145, 147, 148, 149 to the mobile station using the preamble index message 190.

Referring to FIG. 16, an exemplary preamble index message is shown generally at 190. The preamble index message 190 includes a base station identifier field 192 for storing an identifier of the base station, and a preamble index field 194 for storing a preamble index of the base station identified by the base station identifier field 192. In the illustrated embodiment, when the mobile stations 161, 162, 163, 164, 165 enter the network shown in FIG. 1, the base stations 141, 143, 144, 145, 147, 148, 149 serving as anchor base stations. ) Transmits a preamble index message 190 for each of the base stations 141, 143, 144, 145, 147, 148, 149 that are neighbors of the anchor base station. More generally, in the illustrated embodiment, the anchor base station sends a preamble index message 190 for all base stations neighboring the anchor base station to the mobile station joining the network for the anchor base station. These messages may be in the same or different OFDM frames according to the IEEE 802.16e standard. In other embodiments, the preamble indexes of the various base stations can be combined in a single message.

Referring again to FIG. 15, data memory 184 includes a preamble store 196 for storing preamble indexes and associated base station identifiers received within preamble index messages 190 (shown in FIG. 16). The control system 32 stores in the preamble store 196 the preamble indices that the mobile station 161 has sometimes received in various preamble index messages 190.

With continued reference to FIG. 15, program memory 182 determines which base stations identified by base station identifiers in preamble store 196 within the active set of base stations for mobile station 161, and data memory 184. Codes in active set manager 198 for storing a list of base station identifiers of base stations in an active set in active set storage 200 within. The criteria applied by the active set manager 198 are different in various embodiments, but generally include, for example, base station signal conditions, set members recommended by the anchor base station, services provided by the base station, and the network operator of the base station. It includes at least one of. As the base stations in the active set of the mobile station 161 change from time to time, the mobile station 161 transmits active set signals including active set messages (202 as described below) to the anchor base station, thereby anchoring the base stations of the base stations in the active set. Notify them.

Referring to FIG. 17, an exemplary active set message is shown generally at 202. The active set message 202 includes a base station number field 204 for storing the number of base stations in the active set, and one or more base station identifier fields 206 equal to the number stored in the base station number field 204. . In the embodiment shown, mobile station 161 sends an active set message 202 to an anchor base station (such as base station 141) when the base stations in the active set of mobile station 161 change. In alternative embodiments, the mobile station 161 may send a MOB_BSHO-RSP message (defined in the IEEE 802.16e standard) to the anchor base station using the diversity set fields in that message, thereby communicating the active set to the anchor base station. have.

Referring back to FIG. 14, data memory 174 stores an active set store for storing lists of active sets of various mobile stations 161, 162, 163, 164, and 165 for which base station 141 serves as an anchor base station. 208, and the control system 20 stores in the active set store 208 a list of the active sets that the base station 141 has received in various active set messages 202 from time to time.

Distribute system configuration information

With continued reference to FIG. 14, the data memory 174 includes a system configuration information (SCI) repository 210 for storing system configuration information of the base station 141 and neighboring base stations of the base station 141, as shown. Neighbor base stations in the example are base stations 143, 145, 147. In various embodiments, different types of system configuration information may be stored, but in the illustrated embodiment the system configuration information stored in the system configuration information store 210 may be stored for the base station 141 and for each neighboring base station 143,. 145, 147 an identifier of a base station; A preamble index of the base station; Uplink channel information of the base station; And downlink channel information of the base station. However, in alternative embodiments, the system configuration information of the base station may include an identifier of the base station; An identifier of the preamble index of the base station; An identifier of the subchannel index of the base station; Frequency allocation information for the base station; A time / frequency synchronization indicator associated with the base station; Uplink channel information for the base station; Downlink channel information for the base station; A trigger reference indicator associated with the base station; Equivalent isotropic radiated power of the base station; Handover information for the base station; Scheduling service information for the base station; Supported mobility feature information for a base station; A paging group identifier associated with the base station; An identifier of the channel bandwidth of the base station; An identifier of a cyclic prefix of the base station; An identifier of the frame duration of the base station; An identifier of the fast Fourier transform size of the base station; And an operation mode of starting subchannelization of the frame and the channel number of the base station.

With continued reference to FIG. 14, program memory 172 includes codes for system configuration information distributor 212. Referring to FIG. 18, a system configuration information distributor 212 is shown schematically, of mobile stations 161, 162, 163, 164, 165 (referred to below as " first mobile station ") in FIG. Begin at 214 in response to receiving an active set message 202 (shown in FIG. 17) from one.

The system configuration information distributor 212 continues at block 216 with the first base stations identified by base station identifier fields 206 in the active set message 202 (shown in FIG. 17) received from the first mobile station. Compared to the active set list stored in the active set store 208 (shown in FIG. 14) for the mobile station, to determine which new base stations, if present, were added to the active set of the first mobile station (shown in FIG. 14). ) To the microprocessor 170.

The system configuration information distributor 212 proceeds to block 218 for each new base station in the active set of the first mobile station as identified at block 216. Block 218 indicates that the system configuration information of the new base station in the active set of the first mobile station is different from the other mobile station (below and in FIG. Instructs the microprocessor 170 (shown in FIG. 14) to determine whether it should also be transmitted. In a background manner, the system configuration information distributor 212 can run asynchronously so that the base station 141 can receive respective active set messages 202 (shown in FIG. 17) from the first and second mobile stations. ), And these active set messages may include the same new base station in respective sets of first and second mobile stations. The microprocessor (shown in FIG. 14) writes codes at block 218 in response to the active set message 202 from the first mobile station before reaching block 218 in response to the active set message 202 from the second mobile station. Can be reached. In this situation, at block 218, the microprocessor 170 determines that system configuration information of the new base station can be sent to both the first and second mobile stations. In this case, the system configuration information distributor 212 continues at block 220 and returns a system configuration message (222 as described below) in response to receiving active set messages 202 from the first and second mobile stations. Instruct the microprocessor 170 to multicast the containing system configuration signal to the first and second mobile stations. Subsequently, the system configuration information distributor 212 ends.

Referring to FIG. 19, an exemplary system configuration information message is shown generally at 222, and is generally stored in the system configuration information store 210 (shown in FIG. 14) for a new base station in an active set of mobile stations. It includes. In the illustrated embodiment, the system configuration information message includes a base station identifier field 224, a preamble index field 226, a downlink channel field 228, and an uplink channel field 230. However, in various embodiments, system configuration information message 222 may include different information, and in some embodiments information distributed in a MOB_NBR-ADV message as defined, for example, in the IEEE 802.16e standard. It may include.

Referring again to FIG. 18, if at block 218 the microprocessor 170 determines that the system configuration information of the new base station does not need to be sent to any second mobile station, the system configuration information distributor 212 may block 232. Continually instructs the microprocessor 170 to transmit a system configuration information signal to the first mobile station, the system configuration information signal (shown in FIG. 19) for the first mobile station. Subsequently, the system configuration information distributor 212 ends.

Referring again to FIG. 15, the data memory 184 includes a system configuration information store 233 for storing system configuration information received from system configuration information messages 222 (shown in FIG. 19) and controlling. System 32 stores system configuration information in system configuration information store 233 that mobile station 161 sometimes receives within various system configuration information messages 222.

In general, the system configuration information distributor 212 transmits the system configuration information of the base station to the mobile station only when the base station is added to the mobile station's active set, and such a method of distributing the system configuration information of the base station may be useful for distributing system configuration information. May be more efficient than other protocols.

Control channels

In OFDM modulation and other modulation techniques, mobile stations (e.g., mobile stations 161, 162, 163, 164, 165, shown in FIG. 1) and mobile stations (e.g., base stations 141, shown in FIG. A control channel may be established for transmitting control messages between base stations (such as 143, 144, 145, 147, 148, 149). Examples of such control messages include a preamble index message 190 (shown in FIG. 16), an active set message 202 (shown in FIG. 17), and a system configuration information message 222 (shown in FIG. 19). do. Other examples of such control messages include MAC messages defined in the IEEE 802.16e standard.

Referring back to Figures 14 and 15, in the illustrated embodiment, the base station 141 and the mobile station 161 may operate in a single control channel mode or multiple control channel modes. Thus, data memory 174 includes control channel mode storage 234 for storing an indicator of whether base station 141 is in single control channel mode or multiple control channel mode, and data memory 184 A control channel mode store 236 for storing an indicator of whether the mobile station 161 is in a single control channel mode or a multiple control channel mode. The control channel mode stores 234, 236 may be preconfigured or may sometimes be configured to change the control channel modes of the base station 141 and the mobile station 161.

Referring back to FIG. 14, program memory 172 includes codes for power controller 238. In the illustrated embodiment, power controller 238 may be executed for one of mobile stations 161, 162, 163, 164, 165, where base station 141 is an anchor base station thereto. When the base station 141 and the mobile station to which the power controller 238 is running are in the single control channel mode, the power controller 238 controls the power level of the mobile station through the uplink control channel.

Referring to FIG. 20, the codes for power controller 238 are shown schematically, starting at 240. The power controller 238 may be executed periodically or in response to the occurrence of a problem related to the power level used by the mobile station on the uplink control channel, such as, for example, signal interference or poor reception of control messages.

The power controller 238 continues at block 242 to retrieve identifiers of the base stations in the active set of the mobile station that the power controller 238 is running from from the active set storage 208 (shown in FIG. 14), Instructs microprocessor 170 (shown in FIG. 14) to send a channel condition request message (244 as described below) to each base station in the active set of the mobile station that is being executed.

Referring to FIG. 21, an exemplary channel condition request message is shown generally at 244 and includes a mobile station identifier field 246 identifying a mobile station that is the target of which power controller 238 is to be executed.

Referring again to FIG. 14, data memory 174 is a channel for storing condition values indicative of channel conditions of control signals received by base station 141 from various mobile stations 161, 162, 163, 164, and 165. Condition store 248. Base station 141 is a periodically updated channel condition value that reflects signal to noise ratios for various mobile stations 161, 162, 163, 164, and 165 as sometimes measured at base station 141 in the illustrated embodiment. The values in the channel condition store 248 are periodically updated to keep them.

One of the base stations 141, 143, 144, 145, 147, 148, 149 requests a condition (shown in FIG. 21) from the other of the base stations 141, 143, 144, 145, 147, 148, 149 Upon receiving message 244, the base station that received the condition request message 244 returns a channel condition signal including a channel condition message (250 as described below) to the base station that sent the condition request message 244. .

Referring to FIG. 22, an exemplary channel condition message is shown generally at 250. The channel condition message 250 includes a mobile station identifier field 252 that includes the mobile station identifier from the mobile station identifier field 246 of the channel condition request message 244 (shown in FIG. 21) to which the channel condition message 250 is responding. ). The channel condition message 250 also contains a signal to noise ratio field 254 for storing the signal to noise ratio value of the mobile station identified by the mobile station identifier field 252 from the channel condition store 248 (shown in FIG. 14). ).

Referring again to FIG. 20, power controller 238 continues at block 256 from each base station other than the base station executing power controller 238 in the active set of mobile stations that is targeted for power controller 238 to run (FIG. Instructs microprocessor 170 (shown in FIG. 14) to receive channel condition messages 250 (shown in 22).

The power controller 238 continues in block 258 with the microprocessor (shown in FIG. 14) to receive the channel condition of the mobile station that is the target of which the power controller 238 is being executed from the channel condition store 248 of the base station 141. 170). Thus, the codes jointly in blocks 256 and 258 cause the microprocessor 170 to receive channel condition signals from all base stations in the active set of the mobile station that the power controller 238 is running on.

The power controller 238 continues at block 260 instructing the microprocessor 170 to determine an uplink control channel power parameter for the mobile station to which the power controller 238 is to be executed. In the illustrated embodiment, data memory 174 stores channel condition threshold storage 262 (shown in FIG. 14) which stores a threshold signal-to-noise ratio, which is the minimum desired signal-to-noise ratio for receiving control signals from the mobile station. It includes. In the illustrated embodiment, the codes determine the lowest level of the signal to noise ratio levels received at blocks 256 and 258 from base stations in the active set that the power controller 238 is running at block 260, and the channel condition threshold storage. Instructs microprocessor 170 to calculate the ratio of the lowest signal-to-noise ratio levels received at blocks 256 and 258 and the threshold signal-to-noise ratio stored at 262. Thus, in the illustrated embodiment, the uplink control channel power parameter is such that all control signals from the mobile station in the active set of the base station have at least a critical signal to noise ratio signal to noise ratio stored in the channel condition threshold storage 262. In order to be received at the base stations, it is the scaling factor that is needed for the power level at the mobile station that the power controller 238 is the target of execution.

Referring again to FIG. 20, the power controller 238 continues at block 264 to send a power control signal including a power control message (266 as described below) to a mobile station that is the target of which the power controller 238 is to be executed. Instructs the processor 170. The power controller 238 then ends.

Referring to FIG. 23, an exemplary power control message is generally shown at 266 and includes a power control parameter field 268 for storing the power control parameters determined at block 260 (shown in FIG. 20).

Referring again to FIG. 15, data memory 184 stores control channel power storage 270 for storing a power level for transmitting control signals on an uplink control channel when control channel mode of mobile station 161 is single channel mode. ). In response to receiving the power control message 266, the mobile station 161, in the illustrated embodiment, powers the power in the power control parameter field 268 (shown in FIG. 23) to the control channel power in the control channel power store 270. The control channel power stored in the control channel power store 270 is adjusted by multiplying the control parameters. Thus, in the illustrated embodiment, when the power control parameter is greater than 1, the control channel power in the control channel power store 270 is increased by the scaling factor indicated in the power control parameter, and when the power control parameter is less than 1, The control channel power in the control channel power store 270 is reduced by the scaling factor indicated in the power control parameter.

The power controller 238 causes transmission to a single parameter of the mobile station usable by the mobile station to facilitate the reception of control messages sent by the mobile station at all base stations in the mobile station's active set, advantageously at the mobile station. Either reduce processing time or reduce additional transmissions associated with the mobile station that may be needed in known protocols for power control.

Multiple control channels mode

Referring again to FIG. 14, program memory 172 includes codes for control channel allocator 272. When the control channel mode store 234 indicates that the control channel mode is a multi-control channel mode, the microprocessor 170 executes the control channel allocator 272 to execute each control for each base station in the mobile station's active set. Assign a control channel to one of the mobile stations 161, 162, 163, 164 or 165.

Referring to FIG. 24, a control channel allocator 272 is shown schematically, and in response to receiving the active set message 202 (shown in FIG. 17) from the mobile station, the control channel mode store 234 controls the control channel. Beginning at 274 when the mode indicates a multiple control channel mode.

The control channel allocator 272 continues at block 276 to determine which new base stations, if present, have been added to the active set of the mobile station that sent the active set message 202 received at 274 (shown in FIG. 14). ), So that the codes in block 276 are substantially the same as the codes in block 216 shown in FIG. 18.

With continued reference to FIG. 24, control channel allocator 272 executes blocks 278 and 280 for each new base station identified at block 276. The codes assign a control channel from among a plurality of available control channels for the mobile station to transmit uplink control signals to new base stations in the active set of the mobile station at block 278, and the codes are controlled by the microprocessor 170 at block 280. Send a channel assignment message (282 as described below) to the mobile station.

Referring to FIG. 25, an exemplary control channel assignment message is shown generally at 282, with a base station in base station identifier field 284 and base station identifier field 284 for storing an identifier of a new base station added to an active set of mobile stations. And a channel identifier field 286 for storing an identifier of a channel assigned to the mobile station for transmitting uplink control signals to the base station identified by the identifier.

Referring again to FIG. 24, when control channel allocator 272 executes blocks 278 and 280 for each new base station identified at block 276, control channel allocator 272 ends.

Referring again to FIG. 15, data memory 184 includes a control channel assignment store 288 for storing control channel assignments as received in control assignment messages 282 (shown in FIG. 25), Control system 32 sometimes stores control channel assignments as received in control assignment messages 282 in control channel assignment store 288.

With continued reference to FIG. 15, program memory 182 may store code for uplink controller 290 to control the transmission of uplink control commands when control mode storage 236 indicates that control channel mode is a multiple control channel mode. Include them.

Referring to FIG. 26, an uplink controller 290 is shown schematically, beginning at 292 in response to receiving a control message. The control message received at 292 may be any control message to be transmitted from the mobile station 161 to base stations in the active set of the mobile station 161, such as, for example, conventional MAC messages.

For each base station in the active set (as identified in active set storage 200 shown in FIG. 15), uplink controller 290 executes codes at blocks 294 and 296. The codes direct microprocessor 180 (shown in FIG. 15) to identify the control channel assigned to the base station as identified in control channel assignment store 288 at block 294. The codes instruct the microprocessor 180 to transmit a control message to the base station on the assigned control channel identified by the codes in block 294 at block 296. The uplink controller 290 then ends.

Advantageously, the mobile station 161 can determine respective power levels for each of the control channels identified in the control channel assignment store 288, which respective power levels are for example within the active set of the mobile station 161. It can be adapted to specific situations such as distance, noise conditions and other interference associated with each of the base stations. Thus, the various control channels identified in the control channel allocation store 288 facilitate transmitting control channels at respective power levels that can be identified for each of the base stations in the active set.

Ranging

Referring to FIG. 1, as described above, the mobile station 161, 162, 163, 164 or 165 is one of the base stations 141, 143, 144, 145, 147, 148, 149 in the active set of the mobile station and the mobile station. Data representing the distances between the above can be obtained. Since the mobile station is generally located at different distances from the base stations in the active set of the mobile station, the uplink signals from the mobile station travel different distances before reaching the various base stations in the active set, and thus to various base stations in the active set. Reach different times. For example, such time differences may cause interference since signals from one base station may arrive at the base station faster or slower than intended, and may interfere with, for example, previous or subsequent signals from other mobile stations.

Referring to FIG. 14, program memory 172 includes codes for ranging initiator 298 that may be executed for a mobile station where base station 141 is an anchor base station thereto. Referring to FIG. 27, the ranging initiator 298 is schematically illustrated and begins at 300. The ranging initiator 298 may be executed periodically by the microprocessor 170 (shown in FIG. 14), or, for example, because the mobile station added a new base station to its active set or the mobile station from other mobile stations. Since it has repeatedly caused interference with the signals, it can be executed in response to an indication that the mobile station needs new or updated ranging information.

The ranging initiator 298 continues at block 302 instructing the microprocessor 170 (shown in FIG. 14) to determine a reference code (also referred to as a “ranging code”). In the illustrated embodiment, the reference code generated at block 302 is a pseudo random binary number, but in other embodiments the reference code may be, for example, a predetermined code for each mobile station.

The ranging initiator 298 continues at block 304 to instruct the microprocessor 170 to determine a reference time for the mobile station to transmit a signal comprising the reference code determined at block 302. As described above with respect to FIGS. 14 and 15, the clocks 176, 186, and the base stations 143, 144, 145, 147, 148, 149 and mobile stations, respectively, of the base station 141 and the mobile station 161. Corresponding clocks of 162, 163, 164, and 165 are synchronized in the illustrated embodiment, which defines sequential time frames for data transmission. In block 304 the codes instruct the microprocessor 170 to determine a reference time, which is a particular OFDM frame as determined by the synchronized clocks described above in the illustrated embodiment.

With continued reference to FIG. 27, the ranging initiator 298 continues at block 306 with a ranging resource message (as described below) to other base stations in the active set of the mobile station that is the target of the ranging initiator 298 being executed. Instruct microprocessor 170 to transmit a ranging resource signal, including 308.

Referring to FIG. 28, an exemplary ranging resource message is shown generally at 308. The ranging resource message 308 is a mobile station identifier field 309 for storing the identifier of the mobile station that is the target of the ranging initiator 298, and the reference code determined in block 302 (shown in FIG. 27). Reference code field 310 and a reference time field 312 for storing the reference time determined at block 304 (shown in FIG. 27).

Referring again to FIG. 27, the ranging initiator 298 continues to block 314, ranging from a ranging command message (316 as described below) to the mobile station to which the ranging initiator 298 is to be executed. Instructs the microprocessor 170 to send a command signal.

Referring to FIG. 29, an exemplary ranging command message is shown generally at 316. The ranging command message 316 is a reference code field 318 for storing the reference code determined in block 302 (shown in FIG. 27) and a reference for storing the reference time determined in block 304 (shown in FIG. 27). A time field 320.

Referring again to FIG. 15, program memory 182 includes codes for ranger 322. Referring to FIG. 30, a ranger 322 is shown schematically, at a reference time specified by the reference time field 320 of the ranging command message 316 (shown in FIG. 29) received at the mobile station 161. It starts at 324 when it is reached. Ranger 322 continues at block 326 with the ranging signal containing the reference code specified by reference code field 318 of ranging command message 316 (shown in FIG. 29). Instruct the microprocessor 180 (shown in FIG. 15) to transmit to the base stations in the set. The ranger 322 then ends. In alternative embodiments, the ranger 322 is configured to receive the ranging signal at base stations within the active set of the mobile station 161 at a time closer to the reference time specified by the reference time field 320. May begin before a specific time interval of the reference time specified by 320). This particular time interval may reflect, for example, the expected signal transmission time based on estimated distances for base stations in the active set or based on previously acquired data reflecting those distances.

Accordingly, base stations in the active set of mobile station 161 receive a ranging signal that includes a ranging code transmitted in response to the codes of block 326, each of which receives a ranging signal at each time. . Referring again to FIG. 27, the ranging initiator 298 continues at block 328 in which, in response to the codes at block 326 (shown in FIG. 30), the reference time determined at block 304 and the base station 141 are determined by the mobile station. Instructs the microprocessor 170 (shown in FIG. 14) to calculate the time difference between the times of receiving the ranging signal transmitted from FIG.

The other base stations in the active set of the mobile station 161 also have a respective time difference between the reference time and each time the base station in the active set receives the ranging signal in response to the codes in block 326 (shown in FIG. 30). These other base stations transmit respective offset signals to base station 141, including respective offset messages (330 as described below) identifying each time difference calculated at that base station.

Referring to FIG. 31, an exemplary offset message is shown generally at 330, with a base station identifier field 332 identifying a base station whose time difference has been calculated, a mobile station identifier field 334 identifying a mobile station whose time difference has been calculated, and A time difference field 336 that identifies the time difference calculated as described above.

Referring again to FIG. 27, the ranging initiator 298 continues at block 338 with various offsets (shown in FIG. 31) from other base stations in the active set of the mobile station that is the target of the ranging initiator 298 being executed. Instructs the microprocessor 170 (shown in FIG. 14) to receive the messages 330. The ranging initiator 298 then continues at block 340 with a ranging control signal comprising a ranging control message (344 or 348 as described below) to the mobile station to which the ranging initiator 298 is to be executed. Instructs microprocessor 170 to transmit.

Referring again to FIG. 14, the data memory 174 includes a ranging mode store 342 for storing an indicator of the ranging mode of the base station 141. In the illustrated embodiment, the ranging mode indicated by the ranging mode store 342 may be a single ranging parameter mode or a multiple ranging parameter mode. The ranging mode identified by the ranging mode store 342 may be preconfigured or alternatively sometimes configured.

Referring to FIG. 32, a single ranging parameter ranging control message is generally shown at 344 and includes an average time difference field 346. When the ranging mode store 342 indicates a single ranging parameter ranging mode, the codes at block 340 calculate the average of the time differences received at blocks 328 and 338 (shown in FIG. 27) and single ranging. The microprocessor stores the average in the average time difference field 346 of the parameter ranging control message 344 and transmits the single ranging parameter ranging control message 344 to the mobile station that is the target of the ranging initiator 298. Indicate at 170.

Alternatively, when the ranging mode store 342 indicates a multiple ranging parameter ranging mode, the codes in block 340 (shown in FIG. 27) may be used to generate a multiple ranging parameter ranging control message. 170, an exemplary multi-parameter ranging control message is shown generally at 348 in FIG. 33. Referring to FIG. 33, the multiple ranging parameter ranging control message 348 includes at least one base station identifier 350 that identifies each of the base stations in the active set of mobile stations that are to be executed by the ranging initiator 298, and A plurality of time difference fields 352, each time difference field corresponding to one of the base station identifiers 350, storing a time difference associated with the base station as received at blocks 328 and 338 (shown in FIG. 27). do. When the ranging mode store 342 indicates the multiple ranging parameter ranging mode, the codes at block 340 (shown in FIG. 27) generate the multiple ranging parameter ranging control message 348, and the ranging Instructs the microprocessor 170 to send the multiple ranging parameter ranging control message 348 to the mobile station that is the initiator 298 is the target of execution.

As noted above, in alternative embodiments, active sets may exclude anchor base stations, but may include some or all of the neighbor base stations and / or one or more relay stations of the anchor base station, or none. . In such embodiments, the codes at block 328 may be omitted, and the codes at block 340 will exclude the time differences received at block 328.

Referring again to FIG. 15, the data memory 184 stores a ranging data store for storing ranging data received from the ranging control messages 344, 348 transmitted in block 340 (shown in FIG. 27). 354). The mobile station 161 references the ranging data in the ranging data store 354 to facilitate transmission of uplink signals to be received at various base stations in the active set of the mobile station 161 at times based on the ranging data. This facilitates the arrival of signals close to the times that can be allocated, thereby preventing interference with uplink signals from other mobile stations. Advantageously, the process described above periodically updates ranging data in the ranging data store 354 of the mobile station 161 for the base stations that the mobile station 161 has identified for its active set in the active set store 200. To facilitate efficient handover of the mobile station from the anchor base station to the target base station in the active set of base stations.

Handover  Acknowledgment

Referring again to FIG. 1, as described above, one of the mobile stations 161, 162, 163, 164, 165 may occasionally initiate a handover from its anchor base station to another of the base stations. In various embodiments, different criteria may be associated in the determination of when the mobile station will initiate a handover from its anchor base station to the target base station, but these criteria are often for example relative signal strength of the anchor base station and the target base station. Services available from the anchor base station and the target base station, radio operators of the anchor base station and the target base station, and recommended target base stations transmitted by the anchor base station. In one embodiment according to the IEEE 802.16e standard, mobile stations and base stations can control various control messages such as MOB_BSHO-REQ, MOB_MSHO-REQ, MOB_BSHO-RSP and MOB_HO-IND messages to communicate information and decisions regarding handovers. Exchange them.

Referring again to FIG. 15, program memory 182 generally determines when to initiate a handover from a current anchor base station to a target anchor base station and includes codes for handover handler 356 to implement such a determination. do.

Referring to FIG. 34, a handover handler 356 is schematically depicted in the microprocessor 180 (shown in FIG. 15) to determine that a handover from the anchor base station of the mobile station 161 to the target base station will be made. Begin at block 358, which contains codes for pointing. The codes in block 358 may implement one or more of the criteria or other criteria described above for determining that a handover will occur.

The handover handler 356 continues at block 360 to send a handover indication signal to the anchor base station, including a handover indication message (362 as described below) that the handover determined at block 358 will occur. ).

Referring to FIG. 35, an exemplary handover indication message is generally shown at 362 and includes a target base station identifier field 364 for storing an identifier of the target base station determined at block 358 (shown in FIG. 34).

Referring back to FIG. 14, program memory 172 includes codes for handover acknowledgment responder 366. Referring to FIG. 36, a handover acknowledgment responder 366 is schematically shown, with a handover indication message (shown in FIG. 35) transmitted by the base station 141 from the mobile station at block 360 (shown in FIG. 34). Begins at 368 when receiving 362. The handover acknowledgment responder 366 starts at block 370 and sends a handover acknowledgment signal including a handover acknowledgment message (372 as described below) to the mobile station that transmitted the handover indication message determined at 368. Instructs microprocessor 170 (shown in FIG. 14) to transmit.

Referring to FIG. 37, an exemplary handover acknowledgment message is schematically illustrated at 372 and includes an acknowledgment field 374. In the illustrated embodiment, the acknowledgment response field includes a binary flag, which is set to 1 if the handover indication message received at 368 is received without error, and the handover indication message received at 368 is If received with a predetermined error, it is set to zero.

Referring again to FIG. 34, the handover handler 356 continues at block 376 to instruct the microprocessor 180 (shown in FIG. 15) to implement the handover determined at block 358. Handover may be implemented by one of many known protocols, such as, for example, protocols established in the IEEE 802.16e standard.

The handover handler 356 continues at block 378 with the handover acknowledgment message (shown in FIG. 37) sent by the mobile station 161 by the anchor base station 141 at block 370 (shown in FIG. 36). Instructs microprocessor 180 to determine whether 372 has been received. If so, the handover handler 356 terminates. Otherwise, the handover handler 356 continues to block 380 to resend the handover indication message sent at block 360 and instruct the microprocessor 180 to wait for a predefined period before returning to block 378. do. Thus, blocks 378 and 380 are repeated until mobile station 161 confirms that base station 141 has received a handover indication message. Blocks 378 and 380 are executed after block 376, but in other embodiments block 376 is executed after blocks 378 and 380 so that the handover may be postponed until an acknowledgment from the anchor base station is received. The handover indication message retransmitted at block 378 may in some examples prevent the anchor base station 141 from continuing to attempt to communicate with the mobile station 161 after the mobile station 161 completes the handover to the target base station, This can advantageously prevent unnecessary interference and congestion. The retransmitted handover indication message at block 378 may also ensure that the anchor base station notifies the target base station that the mobile station will perform a handover to the target base station, since the anchor base station did not receive the handover indication message. Advantageous communication interruptions that can occur if the target base station is not ready to communicate with the mobile station can be advantageously avoided.

While specific examples of communication systems implementing embodiments of the present invention have been provided above, embodiments of the present invention differ from the specific examples provided above, but have communication systems having architectures that operate in a manner consistent with the implementation of the embodiments described herein. It should be understood that they can be implemented using the following.

While specific embodiments of the invention have been described and illustrated, such embodiments should be considered as merely illustrative of the invention, not as limiting the invention as interpreted in accordance with the appended claims.

Claims (31)

A method of facilitating handover of a mobile station from an anchor base station to a target base station, comprising:
Receiving a handover indication signal from the mobile station at the anchor base station indicating that the mobile station will perform a handover from the anchor base station to the target base station; And
Transmitting an acknowledgment signal to the mobile station confirming that the anchor base station has received the handover indication signal;
≪ / RTI > As a base station apparatus,
An interface for facilitating wireless communication with a mobile station; And
A processor in communication with the interface
Including,
The processor comprising:
Receive from the interface a handover indication signal from the mobile station indicating that the mobile station will perform a handover from the base station apparatus to a target base station;
Cause the interface to transmit an acknowledgment signal to the mobile station confirming that the base station apparatus has received the handover indication signal;
A base station apparatus configured to be operable. As a base station apparatus,
Means for receiving, from a mobile station, a handover indication signal indicating that the mobile station will perform a handover from the base station apparatus to a target base station; And
Means for transmitting an acknowledgment signal to the mobile station confirming that the base station apparatus has received the handover indication signal
Base station device comprising a. A method for facilitating a mobile station in wireless communication with an anchor base station obtaining data indicative of distances between base stations and base stations in an active set of base stations in wireless communication with the mobile station;
The active set includes a subset of neighboring base stations of the anchor base station,
The method comprises:
Transmitting, from the anchor base station to each other base station in the active set, a ranging resource signal identifying a reference code and a reference time associated with the mobile station;
Cause the mobile station to transmit a ranging signal containing the reference code to each base station of the active set at a predetermined time in response to the reference time, so that each base station of the active set has the ranging at each time Receiving a signal;
Receiving, from each base station of the active set, a respective offset signal identifying a respective time difference between the reference time and each time the base station of the active set has received the ranging signal; And
Transmitting a ranging control signal to the mobile station in response to the respective offset signals
≪ / RTI > 5. The method of claim 4, further comprising generating the reference code from pseudo-randomly generated code. 5. The method of claim 4, wherein transmitting the ranging control signal comprises ranging which represents an average of respective time differences between the reference time and respective times at which each base station of the active set received the ranging signal. Transmitting a control signal. 5. The method of claim 4, wherein transmitting the ranging control signal comprises transmitting a plurality of ranging control signals, each of the plurality of ranging control signals associated with a respective base station of the active set. And indicating a respective time difference between the reference time and each time the base station of the active set receives the ranging signal. 5. The method of claim 4, wherein the active set further comprises the anchor base station. As a base station apparatus,
A first interface for facilitating wireless communication with a mobile station;
A second interface for facilitating communication with at least one neighboring base station in an active set in wireless communication with the mobile station; And
A processor in communication with the first interface and a second interface
Including,
The processor comprising:
Cause the second interface to transmit a ranging resource signal identifying a reference code and a reference time associated with the mobile station to the at least one neighboring base station in the active set;
Sending a ranging command signal to the mobile station instructing the mobile station to transmit a ranging signal containing the reference code to each base station in the active set at a predetermined time in response to the reference time; Let each base station in the active set receive the ranging signal at a respective time;
Receive from the second interface a respective offset signal from each neighboring base station in the active set, each offset signal between the reference time and each time a neighboring base station in the active set receives the ranging signal Identifying each time difference of-;
Cause the first interface to transmit a ranging control signal to the mobile station in response to each of the respective offset signals.
A base station apparatus configured to be operable. 10. The base station apparatus of claim 9, wherein the processor is further operable to generate the reference code from a pseudo random generated code. 10. The base station apparatus of claim 9, wherein the ranging control signal represents an average of each of the respective time differences between the reference time and each time each base station in the active set receives the ranging signal. 10. The apparatus of claim 9, wherein the ranging control signal comprises a plurality of ranging control signals, each of the plurality of ranging control signals associated with each of each base station of the active set, the reference time and the respective ones. A base station apparatus indicating a respective time difference between respective times at which a base station of the base station receives the ranging signal. 10. The method of claim 9,
The active set further comprises the device,
The processor comprising:
Receive the ranging signal from the mobile station from the first interface;
Calculate a time difference between the reference time and the time the device receives the ranging signal from the mobile station;
Cause the first interface to transmit the ranging control signal to the mobile station in response to a time difference between the reference time and the time the device receives the ranging signal from the mobile station.
A base station apparatus further configured to be operable. A base station apparatus configured to wirelessly communicate with a mobile station and configured to communicate with at least one neighboring base station in an active set that is in wireless communication with the mobile station, the base station apparatus comprising:
Means for transmitting a ranging resource signal identifying a reference code and a reference time associated with the mobile station to the at least one neighboring base station in the active set;
Transmitting a ranging command signal to the mobile station instructing the mobile station to transmit a ranging signal including the reference code to each base station in the active set at a predetermined time in response to the reference time, respectively. Means for causing a base station of to receive the ranging signal at each time;
Means for receiving a respective offset signal from each base station in the active set, each offset signal representing a respective time difference between the reference time and each time a base station in the active set received the ranging signal. Identifies-; And
Means for transmitting a ranging control signal to the mobile station in response to each of the respective offset signals
Base station device comprising a. As a method of distributing system configuration information of a base station,
Receiving, from a first mobile station having a first active set of base stations, a first active set signal indicating that the first mobile station has added the base station to the first active set; And
In response to receiving the first active set signal, transmitting a system configuration information signal comprising the system configuration information of the base station to the first mobile station;
≪ / RTI > The system of claim 15, wherein the system configuration information of the base station comprises: an identifier of the base station; An identifier of the preamble index of the base station; An identifier of a subchannel index of the base station; Frequency allocation information for the base station; A time / frequency synchronization indicator associated with the base station; Uplink channel information for the base station; Downlink channel information for the base station; A trigger reference indicator associated with the base station; Equivalent isotropic radiated power of the base station; Handover information for the base station; Scheduling service information for the base station; Supported mobility feature information for the base station; A paging group identifier associated with the base station; An identifier of the channel bandwidth of the base station; An identifier of a cyclic prefix of the base station; An identifier of a frame duration of the base station; An identifier of a fast Fourier transform size of the base station; And one or more information in a group consisting of an operation mode of starting subchannelization of a frame and channel number of the base station. 16. The method of claim 15, further comprising receiving, from a second mobile station having a second active set of base stations, a second active set signal indicating that the second mobile station has added the base station to the second active set. And transmitting the system configuration information signal to the first mobile station multicasting the system configuration information signal to the first mobile station and the second mobile station in response to receiving a first indicator signal and a second indicator signal. How to include. As a base station apparatus,
An interface to facilitate wireless communication with a first mobile station having a first active set of base stations;
Computer readable memory having a storage for storing system configuration information of a plurality of base stations; And
A processor in communication with the interface and the computer readable memory
Including,
The processor comprising:
Receive from the interface a first active set signal from the first mobile station indicating that the first mobile station has added one of the plurality of base stations to the first active set;
Cause the interface to, in response to receiving the first active set signal, transmit to the first mobile station a system configuration information signal comprising system configuration information of the one of the plurality of base stations;
A base station apparatus configured to be operable. 19. The apparatus of claim 18, wherein the system configuration information of the base station comprises: an identifier of the base station; An identifier of the preamble index of the base station; An identifier of a subchannel index of the base station; Frequency allocation information for the base station; A time / frequency synchronization indicator associated with the base station; Uplink channel information for the base station; Downlink channel information for the base station; A trigger reference indicator associated with the base station; Equivalent isotropic radiated power of the base station; Handover information for the base station; Scheduling service information for the base station; Supported mobility feature information for the base station; A paging group identifier associated with the base station; An identifier of the channel bandwidth of the base station; An identifier of a cyclic prefix of the base station; An identifier of a frame duration of the base station; An identifier of a fast Fourier transform size of the base station; And one or more information in a group consisting of an operation mode of starting subchannelization of a frame and channel number of the base station. The method of claim 18,
The processor is further configured to interface the second active set signal from the second mobile station indicating that a second mobile station having a second active set of base stations added the one of the plurality of base stations to the second active set. Is further operable to receive from;
And the processor is further operable to cause the interface to multicast the system configuration information to the first mobile station and the second mobile station in response to receiving a first indicator signal and a second indicator signal. As a base station apparatus,
Means for storing system configuration information of the plurality of base stations;
Means for receiving an active set signal from a mobile station having an active set indicating that the mobile station has added one base station of the plurality of base stations to the active set; And
Means for transmitting to said mobile station a system configuration information signal comprising said system configuration information of said one of said plurality of base stations in response to receiving said active set signal;
Base station device comprising a. A method of controlling a mobile station in wireless communication with a plurality of base stations via an uplink control channel,
Receiving a respective channel condition signal from each base station of the plurality of base stations, each channel condition signal being each of the control signals received from the mobile station via the uplink control channel at one of the plurality of base stations; Indicates a channel condition of-;
Determining an uplink control channel power parameter in response to the respective channel condition signals; And
Transmitting a power control signal comprising the uplink control channel power parameter to the mobile station;
≪ / RTI > 23. The method of claim 22, wherein each of the channel conditions comprises a signal to noise ratio. 24. The method of claim 23, wherein determining the uplink control channel power parameter comprises a threshold signal to noise ratio and the control signals received from the mobile station via the uplink control channel at each base station of the plurality of base stations. Determining the ratio of the lowest of each signal to noise ratio. As a base station apparatus,
A first interface for facilitating wireless communication with a mobile station;
A second interface for facilitating communication with at least one neighboring base station in an active set in wireless communication with the mobile station; And
A processor in communication with the first interface and a second interface
Including,
The processor comprising:
Receive each channel condition signal from each neighbor base station of the active set from the second interface, wherein each channel condition signal is received from the mobile station via an uplink control channel at the neighbor base station of the active set; Indicating a channel condition of each of the signals;
Channel conditions of control signals received from the mobile station via the uplink control channel in the apparatus; And determine an uplink control channel power parameter in response to respective channel condition signals received from the at least one neighbor base station of the active set;
Cause the first interface to transmit a power control signal including the uplink control channel power parameter to the mobile station;
A base station apparatus configured to be operable. 27. The base station apparatus of claim 25, wherein each of the channel conditions comprises a signal to noise ratio. 27. The apparatus of claim 26, wherein the processor further comprises: a threshold signal to noise ratio and a signal to noise ratio of control signals received from the mobile station via the uplink control channel at the apparatus; And determine, at each neighboring base station of the active set, the uplink control channel power parameter in response to the ratio of the lowest of the respective signal to noise ratios of the control signals received from the mobile station over the uplink control channel. A base station apparatus configured to be operable. A base station apparatus configured to wirelessly communicate with a mobile station and configured to communicate with at least one neighboring base station in an active set that is in wireless communication with the mobile station, the base station apparatus comprising:
Means for receiving respective channel condition signals from each neighboring base station of the active set, each channel condition signal being each of control signals received from the mobile station via an uplink control channel at the neighboring base station of the active set; Indicates a channel condition of-;
Channel conditions of control signals received from the mobile station via the uplink control channel in the apparatus; And means for determining an uplink control channel power parameter in response to respective channel condition signals received from the at least one neighboring base station of the active set. And
Means for transmitting to the mobile station a power control signal comprising the uplink control channel power parameter.
Base station device comprising a. A method of transmitting a control signal to a plurality of base stations in an active set of a mobile station, the method comprising:
For each base station in the active set, transmitting the control signal to the base station on each control channel
≪ / RTI > As a mobile station device,
An interface for facilitating wireless communication with a plurality of base stations in an active set of the device; And
A processor in communication with the interface, operatively configured to transmit a control signal on each control channel to each base station in the active set
Mobile station device comprising a. As a mobile station device,
Means for facilitating wireless communication with a plurality of base stations in an active set of the device; And
Means for transmitting a control signal on each control channel to each base station in the active set
Mobile station device comprising a.

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