• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A low complexity antenna element is used to reduce interference in the communication device. In at least one embodiment, phase and magnitude values associated with antenna elements in the less complex array are dynamically adjusted during device operation to enforce predetermined quality criteria (eg, SINR).
    公开号:KR20040070336A
    申请号:KR10-2004-7005234
    申请日:2002-10-04
    公开日:2004-08-07
    发明作者:옐린다니엘；빈쉬톡니르
    申请人:인텔 디에스피씨；
    IPC主号:
    专利说明:

    Interference reduction method and communication device in a communication device {INTERFERENCE REDUCTION USING LOW COMPLEXITY ANTENNA ARRAY}
    [2] In cellular communication systems, a number of wireless base stations are typically used to provide communication services to mobile users within the system. Each base station will often serve a number of users in a coverage area or cell associated with the base station. In order to allow multiple users to share one base station, multiple access schemes are typically used. One increasingly popular multiple access technique is code division multiple access (CDMA). In a CDMA based system, a number of substantially orthogonal codes (usually taking the shape of pseudorandom noise sequences) are used to spread spectrum modulate user signals within the system. Each modulated user signal has an overlapping frequency spectrum along with other modulated user signals associated with the base station. However, since the underlying modulation codes are orthogonal, each user signal can be independently demodulated by performing a correlation operation using the appropriate code.
    [3] In at least one CDMA based cellular standard, each base station of the system maintains a pilot channel that continuously transmits a predetermined pilot sequence. These pilot signals may be used by the user of the system to perform channel estimation, handover operations and / or other functions, for example. Pilots from different base stations are sometimes distinguished by the time offset between individual base stations. Therefore, a pilot with a particular time offset (eg from an absolute time reference) will be known to originate from the corresponding base station. As can be appreciated, communication devices operating within a cellular based system implementing CDMA will often receive overlapping communication signals from a variety of different sources (eg, other base stations, etc.). These overlapping signals may indicate interference in the system and degrade system performance. Therefore, any reduction in such interference may enhance the quality of the corresponding communication link or increase the capacity of the system. Therefore, there is a general need for a method and structure for reducing interference in a cellular communication system.
    [1] TECHNICAL FIELD The present invention generally relates to communication systems, and more particularly to interference reduction techniques used within such systems.
    [4] 1 is a simplified plan view illustrating a cellular communication system that may utilize the principles of the present invention;
    [5] 2 is a block diagram illustrating a receiver system in accordance with an embodiment of the present invention capable of reducing interference;
    [6] 3 is a block diagram illustrating a receiver system according to another embodiment of the present invention;
    [7] 4 is a flow diagram illustrating a method of reducing interference in a communication device according to an embodiment of the present invention;
    [8] 5 is a timing diagram illustrating timing associated with the method of FIG. 4 in accordance with an embodiment of the present invention.
    [9] In the detailed description that follows, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be implemented. These embodiments are described in sufficient detail to enable those skilled in the art to implement the invention. Although different, the various embodiments of the invention need not necessarily be mutually exclusive. For example, certain features, structures or features described herein in connection with one embodiment can be implemented in other embodiments without departing from the spirit and spirit of the invention. In addition, the positioning and alignment of the individual elements in each disclosed embodiment may be changed without departing from the spirit and spirit of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, and is interpreted according to the full range of equivalents defined by the claims. In the drawings, like reference numerals refer to the same or similar functionality throughout the several views.
    [10] The present invention relates to a method and structure for reducing interference in a communication system using a relatively low complexity antenna arrangement. This method and structure can be used, for example, in mobile communication devices (eg, cellular telephones, etc.) to reduce the potential for interfering signals. Two or more antenna elements are provided in a communication device, at least one of which has adjustable weights (eg, magnitude and / or phase). The adjustable element (s) is adjusted during system operation to enforce preselected interference related quality criteria (eg, signal to interference and noise ratio (SINR)). The principles of the present invention can be implemented in a variety of different communication systems and devices and are particularly useful in cellular type communication systems using CDMA techniques.
    [11] 1 is a simplified plan view illustrating a cellular communication system 10 that may utilize the principles of the present invention. As shown, the cellular communication system 10 includes a number of base stations 12, 14 that are physically distributed within an area. Each base station 12,14 has a corresponding coverage area or cell 16 to which the base station 12,14 provides wireless communication services to mobile users. As used herein, the term serving base station refers to a base station that currently provides communication services to a particular user. For example, referring to FIG. 1, base station 14 operates as a serving base station for mobile user 18 located within cell 16 of base station 14. Mobile user 18 will typically receive signals from the serving base station 14 and multiple base stations 12 within the system 10. As described above, in a CDMA based system, signals received from various base stations may have an overlap spectrum. As can be appreciated, these overlapping signals can negatively affect the communication quality within the system 10.
    [12] 2 is a block diagram illustrating a receiver system 20 according to an embodiment of the present invention. As will be explained in greater detail, this receiver system 20 may output such that signals received within the corresponding communication device have reduced interference. In at least one application, receiver system 20 may be implemented within a mobile communication device operating within a cellular based communication system. This mobile communication device may include, for example, a cellular telephone, a wireless handheld pager, a laptop computer with a wireless transmitter functionality or a personal digital assistant (PDA) and other devices. As illustrated, receiver system 20 includes first and second antenna elements 22, 24, adjustable gain 26, adjustable phase 28, coupler 30, radio frequency (RF). ) Receiver 32, baseband processor 34 and gain and phase controller 36. The first and second antenna elements 22, 24 receive radio frequency (RF) communication signals from the environment. RF communication signals received from the first and second antenna elements 22, 24 may comprise signal components from a number of different base stations, for example. The adjustable gain section 26 and the adjustable phase section 28 controllably change the magnitude and phase associated with the first antenna element 22, respectively. The combiner 30 combines the output signals of the first and second antenna elements 22, 24 and transmits the combined signal to the RF receiver 32.
    [13] The RF receiver 32 processes the combined signal to generate a baseband communication signal. The baseband processor 34 processes the baseband signal to extract user information associated with the user of the communication device. Baseband processor 34 also passes information extracted from the baseband signal to gain and phase controller 36. The gain and phase controller 36 uses the information from the baseband processor 34 to generate gain and phase control information appropriate to the adjustable gain and phase portions 26 and 28. The gain and phase control information generated by the gain and phase controller 36 is dynamically adjusted during system operation to reduce interference in the receiver system 20. In a preferred approach, the gain and phase control information is adjusted to optimize the preselected interference related quality criteria (eg SINR). In this manner, the gain and phase controller 36 may adjust the position of the composite receive beam of the receiver system 20 to support the serving base station while avoiding other base stations nearby (especially base stations with high power). .
    [14] As described above, the outputs of the first and second antenna elements 22, 24 are coupled in the combiner 30 before RF processing is performed in the RF receiver 32. Therefore, even when multiple antenna elements are used, only a single RF path (eg, one intermediate frequency (RF) section, one analog to digital converter, etc.) needs to be provided in the receiver system 20. Conventional phased array principles rely on controlling the receive beam. Any of a variety of different antenna types can be used for the antenna elements 22, 24. For applications in handheld communicators, antenna elements 22 and 24 will preferably be relatively inexpensive structures with a relatively low profile. Some antenna types that may be used may include, for example, microstrip patches, dipoles, monopoles, dielectrics, printed, inverted F, slots, and the like. In at least one embodiment of the present invention, two (or more) different types of antenna elements are used in the communication device. In addition, a better quality antenna element may be used for non-adjustable element (s) (eg, second element 24) than the adjustable element (s) (eg, first element 22), Or vice versa. Antenna elements in the communication device may have the same or different polarization.
    [15] It should be understood that two or more antenna elements can be used in accordance with the present invention, as long as at least one of the antenna elements has a variable size and / or phase that allows beam steering to occur. For example, FIG. 3 is a block diagram illustrating a receiver system 40 according to another embodiment of the present invention. As illustrated, the system 40 includes first and second antenna elements as in the previously described embodiment. System 40 also includes one or more additional antenna elements 42 with corresponding adjustable gains 44 and adjustable phases 46, respectively. During system operation, the gain and phase controller 36 delivers gain and phase control information to the adjustable gain and phase portions associated with each of the adjustable antenna elements 22 and 42. As described above, the gain and phase control information generated by the gain and phase controller 36 is dynamically adjusted during system operation to reduce interference in the system.
    [16] 4 is a flowchart illustrating a method of reducing interference in a communication device according to an embodiment of the present invention. This method may for example be implemented in connection with the receiver system 20 of FIG. 2. This method will be described with respect to the timing diagram of FIG. 5 showing a number of consecutive processing cycles (i.e., starting at (n-1) T, nT and (n + 1) T, respectively) within the digital system. . This period T can be optimized based on the current Doppler rate (ie, mobile speed), which can change in real time during normal system operation, for example. 4, a communication device is first provided (block 50) comprising first and second antenna elements. The first antenna element has an adjustable weight (magnitude and / or phase). The outputs of the first and second antenna elements are combined in the combiner. At the start of the processing period (eg, in nT of FIG. 5), the predetermined weight w (which may be complex) is applied to the first antenna element and held for τ seconds (block 52). As will be explained in more detail, this predetermined weight will evaluate the channel response for the channel between the multiple base stations of interest and each individual antenna element of the communication device. In at least one approach, the predetermined weight will set the size of the first antenna element to zero, effectively removing the first antenna element from the system for a period τ. However, other predetermined weights may also be used. The same predetermined weight may be applied to the first antenna element during each successive period, or different predetermined weights may be applied to successive periods.
    [17] During the period τ of this processing period (see FIG. 5), the combined channel response of the first and second antenna elements is evaluated for each base station of interest (block 54). The combined channel response is the response of the first and second antenna elements after coupling in the combiner. The combined channel response for a particular base station is evaluated using pilot tones received from that base station. Methods for evaluating channel response using received pilot tones are known. The base station of interest can be selected in a variety of different ways. If appropriate resources are available, all base stations in the system can be treated as base stations of interest. In another approach, the N highest power base stations in the system (ie, the base station with the strongest received signal in the communication device) are selected as the base station of interest (where N is a positive integer). The list of highest power base stations is often maintained in the communication device for use in performing handoff operations. In another approach, all base stations with detected power levels above a predetermined threshold level are used as the base station of interest. In another approach, the N strongest paths from different base stations are considered and thus define the base station of interest. As will be apparent to those skilled in the art, other techniques of identifying the base station of interest may be used.
    [18] After the combined channel response is evaluated, the channel response associated with the individual antenna element is calculated for the base station of interest (block 56). In at least one approach, information associated with a previous processing period (e.g., (n-1) T to nT of FIG. 5) may be determined by solving two unknown, two equations of the current processing period (e.g., FIG. Is used to calculate the channel response associated with the individual antenna element for nT to (n + 1) T periods of five). The following two vector equations represent the relationship between the combined channel response and the individual antenna channel response at time [(nT, nT + τ) and ((n-1) T + τ, nT), respectively.
    [19]
    [20] Where h k (t) is the combined channel response at time t associated with base station k (where k = 0 corresponds to the serving base station) and this response is continuously evaluated using well-known evaluation techniques. And can be tracked. C k (t) is the matrix channel response for each antenna at base station k at time t. The element {C k (t)} ij of the matrix C k (t) represents the channel response of the j th path in the i th antenna element. The index j will not be greater than the maximum number of fingers of the corresponding rake receiver. The vector W (n-1) T = (w, 1) is the gain of the antenna for the previous time period [(n-1) T + τ, nT). vector Denotes the vector gain of the antennas using a predetermined weight w applied at time t = nT and maintained for the period nT, nT + τ .. Combined channel response h over time [nT, nT + τ] k (t) was evaluated above (for each base station k of interest) The values of h k (t) and W for the previous time period [(n-1) T, nT] are known. n-1) T + τ, nT] The vector W used for the time period includes the new weights generated at time n-1 T + τ (see FIG. 5) but does not include the predetermined weights. The individual channels C k (t) at the end of the (n-1) T period are the same as the channels at the beginning of the period nT, while the combined channel response h k (t) has different weights. vector( Is different from W (n-1) T). To determine the channel response associated with an individual antenna element, two vector equations for two unknowns at t = nT are solved, i.e. determine the channel response C k (nT) at each antenna element. This is done for each path of each base station of interest. Similar equation solving can be performed for the system using three or more antenna elements.
    [21] Using well-known evaluation techniques, the transmitted power (P k ) of each base station of interest, the pilot power (P d ) of the serving base station, and the white noise variance vector σ = (σ 1 , σ 2 ) at the antenna are evaluated (Block 58). A new weight for the first antenna element is then calculated to maximize the predetermined quality criterion (block 60). In one embodiment, signal to interference and noise ratio (SINR) is used as the quality criterion. In this embodiment, the new weight is determined to maximize the following equation.
    [22]
    [23] Where SF is the pilot spreading factor, operation G (A) returns the sum of the absolute squares of the elements of matrix (A), X H is the conjugate transpose of matrix (X), and X T is the matrix Normal transposition of (X). The last term in the denominator of the equation above relates to white Gaussian noise in the channel and can be ignored in some cases. Other quality criteria that may be used may include, for example, the mean square error (MSE) of the pilot signal, the bit error rate (BER) at the output of the rake receiver, and the like. In one approach, the new weight is selected from a finite set of predetermined weights. By using a finite set of possible weights, the overall system complexity can be reduced.
    [24] After the new weight is determined, this weight is applied to the first antenna element for the remainder of the current processing period (ie, during the next T-τ seconds as shown in FIG. 5) (block 62). The above described process is then repeated for subsequent processing cycles (block 64). In this manner, the receive beam of the communication device is continuously adjusted to reduce the level of interference in the communication device. The method described above can be modified for use in a system having two or more antenna elements (eg, receiver system 40 of FIG. 3).
    [25] While the present invention has been described in connection with certain embodiments, it will be understood that modifications and variations may be made without departing from the spirit and scope of the invention as those skilled in the art will readily appreciate. Such modifications and variations are considered to be within the scope and scope of the invention and in the appended claims.
    权利要求:
    Claims (29)
    [1" claim-type="Currently amended] A method of reducing interference in a communication device,
    Providing a communication device having a first and a second antenna element and a combiner for coupling the first and second antenna elements, the first antenna element having an adjustable weight;
    Determining a separate channel response for the first and second antenna elements for each of a plurality of base stations of interest;
    Determining a weight for the first antenna element to optimize an interference related quality criterion based on the individual channel response
    How to include.
    [2" claim-type="Currently amended] The method of claim 1,
    The communication device comprises two or more antenna elements, and the combiner combines the outputs of the two or more antenna elements.
    [3" claim-type="Currently amended] The method of claim 1,
    Determining the individual channel response,
    Applying a predetermined weight to the first antenna element;
    Estimating a combined channel response for the channel between the first base station of interest and the output of the combiner while the predetermined weight is applied;
    Calculating an individual channel response for the channel between the first base station of interest and the first antenna element using the evaluated combined channel response
    How to include.
    [4" claim-type="Currently amended] The method of claim 3, wherein
    The step of calculating the individual channel response includes determining a weight previously applied to the first antenna element and calculating the individual channel response using the previously applied weight.
    [5" claim-type="Currently amended] The method of claim 1,
    Wherein the weight is a complex weight having a magnitude-related component and a phase related component.
    [6" claim-type="Currently amended] The method of claim 1,
    The interference related quality criteria include signal to interference and noise ratio (SINR).
    [7" claim-type="Currently amended] The method of claim 1,
    The interference related quality criterion comprises a bit error rate (BER).
    [8" claim-type="Currently amended] The method of claim 1,
    The interference related quality criterion comprises a mean squared error (MSE).
    [9" claim-type="Currently amended] The method of claim 1,
    Determining the weights includes selecting weights from a predefined set of possible weights.
    [10" claim-type="Currently amended] A method of reducing interference in a communication device,
    Providing a communication device having first and second antenna elements, the first antenna elements having adjustable weights;
    Applying a predetermined weight to the first antenna element;
    Evaluating a combined channel response for the first and second antenna elements while applying the predetermined weight to a first base station of interest;
    Calculating an individual channel response for the channel between the first and second antenna elements and the first base station of interest using the evaluated combined channel response;
    Determining a new weight for the first antenna element to use the individual channel response to enforce an interference related quality criterion
    How to include.
    [11" claim-type="Currently amended] The method of claim 10,
    Evaluating the combined channel response and calculating individual channel responses for each of the plurality of base stations of interest.
    [12" claim-type="Currently amended] The method of claim 10,
    Evaluating the combined channel response includes identifying and using a pilot signal received from the first base station of interest.
    [13" claim-type="Currently amended] The method of claim 10,
    Applying a predetermined weight includes forcing a magnitude associated with the first antenna element to zero.
    [14" claim-type="Currently amended] The method of claim 10,
    The interference related quality criteria include signal to interference and noise ratio (SINR).
    [15" claim-type="Currently amended] A method of reducing interference in a communication device,
    Providing a communication device having first and second antenna elements, the first antenna elements having adjustable weights;
    Applying a predetermined weight to the first antenna element for a current period;
    Evaluating a combined channel response for the first and second antenna elements while applying the predetermined weight to a first base station of interest;
    Calculating an individual channel response for the channel between each of the first and second antenna elements and the first base station of interest during the current period using the combined channel response;
    Determining a new weighting factor for the first antenna element during the current period, for enhancing the interference related quality criteria using the individual channel response;
    Applying the new weight to the first antenna element during the current period
    How to include.
    [16" claim-type="Currently amended] The method of claim 15,
    Prior to determining the new weight, repeating the step of evaluating the combined channel response and calculating the individual channel response for each of the plurality of base stations of interest.
    [17" claim-type="Currently amended] The method of claim 15,
    Computing the individual channel response includes using antenna weight information from a previous period.
    [18" claim-type="Currently amended] The method of claim 15,
    Computing the individual channel response includes using the combined channel response information from a previous period.
    [19" claim-type="Currently amended] The method of claim 15,
    Computing the individual channel response comprises solving M unknowns of M equations.
    [20" claim-type="Currently amended] The method of claim 15,
    Computing the individual channel response steps for C 1 (t = nT) following the system equation

    , Wherein h 1 (t) is the evaluated combined channel response for the first base station of interest at time t, and W (n-1) T is the previous period [(n-1) T + τ, nT) is the calculated vector gain of the antenna element, C 1 (t) is the matrixed channel response of the first base station of interest for each of the antenna elements at time t, Is the vector gain of the antenna using the predetermined weight.
    [21" claim-type="Currently amended] The method of claim 15,
    The interference related quality criteria include signal to interference and noise ratio (SINR).
    [22" claim-type="Currently amended] The method of claim 15,
    Applying a predetermined weight, evaluating the combined channel response, calculating an individual channel response, determining a new weight and applying during the period following the new weight How to.
    [23" claim-type="Currently amended] A first antenna element and a second antenna element having an adjustable weight;
    A combiner for combining the outputs of the first and second antenna elements to produce a combined signal;
    A controller to control the adjustable weight of the first antenna element
    Including, but the controller,
    A first unit for determining respective channel responses of the first and second antenna elements for each of a plurality of base stations of interest;
    A second unit for determining a weight for the first antenna element that optimizes interference related quality criteria using the individual channel response
    Containing
    Communication system.
    [24" claim-type="Currently amended] The method of claim 23,
    At least one additional antenna element,
    The combiner combines the outputs of the first antenna element, the second antenna element and the at least one additional antenna element to generate the combined signal,
    The first unit determines, for each base station of interest, an individual channel response for the first antenna element, the second antenna element and the at least one additional antenna element.
    Communication device.
    [25" claim-type="Currently amended] The method of claim 23,
    The controller repetitively updating the weight of the first antenna element.
    [26" claim-type="Currently amended] The method of claim 25,
    The controller updating the weight of the first antenna element at intervals that depend on the Doppler rate associated with the communication device.
    [27" claim-type="Currently amended] The method of claim 23,
    The interference related quality criterion comprises a signal to interference and noise ratio (SINR).
    [28" claim-type="Currently amended] The method of claim 23,
    And the first unit determines the individual channel response by regularly applying a predetermined weight to the first antenna element.
    [29" claim-type="Currently amended] The method of claim 23,
    Wherein the first unit determines the respective channel response of the first and second antenna elements using the combined channel response of the first and second antenna elements for each base station of interest.
    类似技术:
    公开号 | 公开日 | 专利标题
    Choi et al.2000|A novel adaptive beamforming algorithm for a smart antenna system in a CDMA mobile communication environment
    JP3641961B2|2005-04-27|Wireless communication device using adaptive array antenna
    USRE39275E1|2006-09-12|Hardware-efficient demodulator for CDMA adaptive antenna array systems
    JP2605648B2|1997-04-30|Despreading code phase detector for SS receiver
    US6347234B1|2002-02-12|Practical space-time radio method for CDMA communication capacity enhancement
    US7092690B2|2006-08-15|Genetic algorithm-based adaptive antenna array processing method and system
    US5999826A|1999-12-07|Devices for transmitter path weights and methods therefor
    EP1719258B1|2009-11-11|Method and apparatus for finger placement in a rake receiver
    JP4268712B2|2009-05-27|Communication apparatus and method for interference suppression in DS-CDMA system
    US8520641B2|2013-08-27|Radio communication device and arrival direction estimation method
    EP0926843B1|2004-05-06|Method and system for operating a cellular system having beamforming antennas
    CA2336307C|2004-05-25|A communication system for transmitting and demodulating a communication signal using an adaptive antenna array
    US8081672B2|2011-12-20|Method and system for channel estimation in a single channel | single-input multiple-output | system
    US8559402B2|2013-10-15|Method and system for channel estimation in a spatial multiplexing MIMO system
    US7376428B2|2008-05-20|Positioning method and radio system
    US7397842B2|2008-07-08|Method and apparatus for combining weight computation in a DS-CDMA RAKE receiver
    EP0872037B1|2002-09-25|Base station equipment, and a method for steering an antenna beam
    AU726702B2|2000-11-16|Radio communication apparatus and transmission power controlling method
    KR100428709B1|2004-04-27|Apparatus for Forward Beamforming using Feedback of Multipath Information and Method Thereof
    US7340279B2|2008-03-04|Wireless communications with an adaptive antenna array
    US5893033A|1999-04-06|Methods for making a faster handover, and a cellular radio systems
    US7277730B2|2007-10-02|Method of allocating radio resources in telecommunication system, and telecommunication system
    US6172970B1|2001-01-09|Low-complexity antenna diversity receiver
    JP3092798B2|2000-09-25|Adaptive transceiver
    US7313417B2|2007-12-25|Transceiver for a base station with smart antenna and a switched beamforming method in downlink
    同族专利:
    公开号 | 公开日
    JP2005506755A|2005-03-03|
    KR100676034B1|2007-01-29|
    US7039135B2|2006-05-02|
    US20030072396A1|2003-04-17|
    EP1435144B1|2006-07-19|
    EP1435144A1|2004-07-07|
    MY133588A|2007-11-30|
    JP4131702B2|2008-08-13|
    AT333725T|2006-08-15|
    CN100397805C|2008-06-25|
    CN1606838A|2005-04-13|
    DE60213268D1|2006-08-31|
    WO2003034615A1|2003-04-24|
    DE60213268T2|2007-08-02|
    US20060135101A1|2006-06-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2001-10-11|Priority to US09/976,200
    2001-10-11|Priority to US09/976,200
    2002-10-04|Application filed by 인텔 디에스피씨
    2002-10-04|Priority to PCT/IB2002/004383
    2004-08-07|Publication of KR20040070336A
    2007-01-29|Application granted
    2007-01-29|Publication of KR100676034B1
    优先权:
    申请号 | 申请日 | 专利标题
    US09/976,200|2001-10-11|
    US09/976,200|US7039135B2|2001-10-11|2001-10-11|Interference reduction using low complexity antenna array|
    PCT/IB2002/004383|WO2003034615A1|2001-10-11|2002-10-04|Interference reduction using low complexity antenna array|
    [返回顶部]