WO2011005727A2 - Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network - Google Patents
Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network Download PDFInfo
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- WO2011005727A2 WO2011005727A2 PCT/US2010/041017 US2010041017W WO2011005727A2 WO 2011005727 A2 WO2011005727 A2 WO 2011005727A2 US 2010041017 W US2010041017 W US 2010041017W WO 2011005727 A2 WO2011005727 A2 WO 2011005727A2
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2691—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation involving interference determination or cancellation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/66—Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
- H04J11/0023—Interference mitigation or co-ordination
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2602—Signal structure
- H04L27/2605—Symbol extensions, e.g. Zero Tail, Unique Word [UW]
- H04L27/2607—Cyclic extensions
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
- H04W16/12—Fixed resource partitioning
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/06—TPC algorithms
- H04W52/10—Open loop power control
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/004—Synchronisation arrangements compensating for timing error of reception due to propagation delay
- H04W56/0045—Synchronisation arrangements compensating for timing error of reception due to propagation delay compensating for timing error by altering transmission time
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2656—Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2666—Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/04—Error control
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/06—TPC algorithms
- H04W52/14—Separate analysis of uplink or downlink
- H04W52/146—Uplink power control
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/04—Large scale networks; Deep hierarchical networks
- H04W84/042—Public Land Mobile systems, e.g. cellular systems
- H04W84/045—Public Land Mobile systems, e.g. cellular systems using private Base Stations, e.g. femto Base Stations, home Node B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Definitions
- Embodiments pertain to wireless communication networks.
- embodiments relate to multi-tier network synchronization and networks that implement an orthogonal frequency division multiple access (OFDMA) communication technique. Some embodiments relate to reducing interference in a multi-tier OFDMA overlay network, including WiMAX networks configured in accordance with IEEE 802.16(m) and networks configured in accordance with 3 GPP-LTE advanced.
- OFDMA orthogonal frequency division multiple access
- a multi-tier overlay network may include a higher tier of higher-tier base stations and higher-tier mobile stations as well as a lower tier of lower-tier base stations and lower-tier mobile stations.
- the lower-tier base stations and mobile stations operate within the footprint of a higher-tier base station.
- One issue with same-frequency multi-tier overlay networks is interference caused by conflicting communications within the same frequency spectrum. Communications within the one tier may interfere with communications within another tier.
- Multi-tier OFDMA overlay networks use cyclic prefixes as a guard interval to, among other things, reduce interference between symbols, however, frames from one tier that arrive outside the cyclic prefix at another tier may cause asynchronous interference. Frames from one tier that arrive within the cyclic prefix at another tier may cause synchronous interference.
- Asynchronous interference is significantly more difficult to manage than synchronous interference.
- FIG. 1 illustrates a multi-tier OFDMA overlay network in accordance with some embodiments
- FIG. 2 illustrates unadjusted frame boundaries that may result in asynchronous interference
- FIG. 3A is a table of various parameters of a multi-tier OFDMA overlay network
- FIG. 3B illustrates a cumulative distribution of timing misalignment errors that may result in asynchronous interference
- FIG. 4 illustrates the advancement of frame boundaries in accordance with some embodiments
- FIG. 5 is a block diagram of a base station in accordance with some embodiments.
- FIG. 6 illustrates a procedure to reduce asynchronous interference in a multi- tier OFDMA overlay network in accordance with some embodiments.
- FIG. 1 illustrates a multi-tier OFDMA overlay network in accordance with some embodiments.
- Multi-tier OFDMA overlay network 100 may comprise two or more tiers including higher tiers and lower tiers. Each tier may include base stations and mobile stations that communicate within their tier.
- a higher tier includes a higher-tier base station (BS) 102 and one or more higher-tier mobile stations, such as higher-tier mobile station (MS) 104, associated with the higher-tier base station 102.
- the lower tier includes a lower-tier base station (LT BS) 112 and one or more lower-tier mobile station, such as lower-tier mobile station (LT MS) 114, associated with the lower-tier base station 112.
- LT BS lower-tier base station
- LT MS lower-tier mobile station
- the multi-tier OFDMA overlay network 100 is illustrated has having only two tiers, the multi-tier OFDMA overlay network 100 may include several tiers.
- the lower-tier base station 112 may communicate with the lower-tier mobile station 114 within a lower-tier service area 113.
- the higher-tier base station 102 may communicate with the higher-tier mobile station 104 within a higher-tier service area 103.
- the lower-tier service area 113 may be located at least partially within the higher-tier service area 103.
- the lower-tier base station 112 and the higher-tier base station 102 may
- the lower-tier base station 112 may communicate with the lower-tier mobile station 114 in accordance with an OFDMA communication technique and the higher-tier base station 102 may communicate with the higher-tier mobile station 104 in accordance with the OFDMA communication technique.
- the lower-tier base station 112 and the higher-tier base station 102 may communicate with their associated mobile stations using a same frequency spectrum.
- the use of the same frequency spectrum for communicating OFDMA frames may result in asynchronous interference when OFDMA frames intended for other device arrive outside the cyclic prefix of an OFDMA frame.
- communicating OFDMA frames may result in synchronous interference when OFDMA frames intended for other device arrive within the cyclic prefix of a frame.
- the lower-tier base station 112 and the higher-tier base station 102 may communicate OFDMA frames with their associated mobile stations using the same set of non-orthogonal OFDM subcarriers. In these embodiments, the lower-tier base station 112 and the higher-tier base station 102 may communicate using at least some non- orthogonal subcarriers.
- the lower-tier base station 112 is configured to reduce asynchronous interference within the multi-tier OFDMA overlay network 100 by adjusting its frame boundaries. This may allow interference to be received synchronously.
- the lower-tier base station 112 may adjust its OFDMA frame boundaries to cause frames communicated by the higher-tier to arrive within a cyclic prefix at the lower- tier base station 112.
- the lower-tier base station 112 may also adjust its OFDMA frame boundaries to cause frames communicated by the lower-tier to arrive within a cyclic prefix at a higher-tier mobile station 104.
- the lower-tier mobile station 114 may also adjust its transmission times as described in more detail below.
- the lower-tier base station 112 may advance its uplink
- the lower-tier base station 112 may also delay its downlink OFDMA frame boundaries, if necessary, to align its downlink OFDMA frame boundaries with downlink frame transmissions of the higher tier.
- the adjustment of the uplink OFDMA frame boundaries may help ensure that the uplink transmissions of the higher-tier mobile station 104 are received within a cyclic prefix at the lower-tier base station 112 to reduce asynchronous interference at the lower-tier base station 112.
- the adjustment of the downlink OFDMA frame boundaries may help ensure that the downlink transmissions of the lower-tier base station 112 to a lower-tier mobile station 114 are received within a cyclic prefix at the higher-tier mobile station 104 to reduce asynchronous interference at the higher-tier mobile station 104.
- the adjustment of frame boundaries by the lower-tier base station 112 and the lower tier mobile station 114 may be particularly important when the higher-tier mobile station 104 resides within the service area 113 of the lower-tier base station 112.
- FIG. 2 illustrates unadjusted frame boundaries that may result in asynchronous interference.
- a scenario is illustrated where a lower-tier mobile station (referred to as a femto mobile station (F-MS)) and its associated lower-tier base station (referred to as a femto base station (F-BS)) use a conventional timing offset adjustment for uplink
- F-MS femto mobile station
- F-BS femto base station
- the F-BS and F-MS operate within the presence of a higher- tier base station, referred to as a macro base station (M-BS) and an associated higher-tier mobile station, referred to as a macro mobile station (M-MS).
- M-BS macro base station
- M-MS macro mobile station
- the M-BS and the F-BS may be separated by a distance Dl
- the M-BS and the M-MS may be separated by a distance D2
- the F-BS and the M-MS may be separated by a distance D3
- the F-MS and F-BS may be separated by a distance D3'.
- the unadjusted timing reference 212 of the F-BS may be delayed with respect to timing reference 202 of the M-BS due to the signal propagation time over distance Dl.
- the unadjusted timing reference 212 of the M-BS may be based on synchronization of a downlink frame from the M-BS received at the F-BS. The effect of synchronization errors on the frame timing may be ignored to simplify the illustration.
- the M-MS advances its uplink
- the M-MS advances its uplink frame relative to the M-BS frame by the propagation delay between M- MS and the M-BS (i.e., over distance D2). If the F-BS's uplink receive frame boundary is not adjusted for this propagation delay over distance Dl, the M-MS 's uplink transmissions may arrive well in advance of the F-BS's frame boundary, possibly outside of the cyclic prefix at the F-BS, depending on distances Dl and D2. This may be particularly an issue when the M- MS is operating within the footprint of the F-BS. Because this interference is asynchronous, it is more difficult to mitigate than interference that is synchronous.
- FIG. 3A is a table of various parameters of a multi-tier OFDMA overlay network. Using the parameters defined in the table of FIG. 3 A, a worst case misalignment of M-MS interference may be estimated as a function of cell size and is shown in the table below.
- the femto footprint is assumed to be small (-100 meters), distance Dl may be approximately equal to distance D2, and distance D3 may negligible (e.g., 100 meters ⁇ 4 samples for 1024 FFT). Also shown is the overall timing misalignment adjusted for errors due to synchronization accuracy. Note that a
- synchronization error may be be , given that both the F-BS and M-MS frame references can be in error by the synchronization accuracy.
- CP- 1/8 cyclic prefix of 1/8 symbol
- cell sizes of approximately 1.5 km may experience significant
- asynchronous interference outside of the cyclic prefix may be precluded as even cell sizes below 1000 meters will be affected.
- FIG. 3B illustrates a cumulative distribution of timing misalignment errors that may result in asynchronous interference.
- the timing errors are calculated based on the distance of a given a location from the center of the cell. It can be seen that for a cell size of 1.5 km, approximately 14% of locations in the cell may experience timing misalignment which exceeds a cyclic prefix of 1/8, which may equals 128 samples. However, for a 2 km cell size, the percentage of locations exceeding a cyclic prefix of 1/8 increases to 50%, which may be considered significant.
- misalignment indicates that for 50% of the misalignments exceeding the cyclic prefix, more than 70% will have a noise floor at -15 dB, for a 2 km cell size.
- the interference from an M-MS may also be severe, even with low-density deployments of femto-cells because an F-MS will adjust its uplink transmission power to lower the interference caused by the macro-overlay network. If an F-MS 's transmit power is reduced to avoid interference to macro-cell users, the signal-to-noise and interference ratio
- SINR at F-MSs may be degraded substantially.
- the SINR for M-MS may be about -20 dB while the SINR for F-BS may be about -13 dB.
- This interference may be significant. If this interference is asynchronous, then the increased noise floor resulting from inter-symbol and inter-carrier interference may preclude effective interference mitigation.
- an F-BS may reduce asynchronous interference by adjusting its frame boundaries. This may allow interference to be received synchronously. To reduce asynchronous uplink interference resulting from timing
- both the F-BS and the F-MS may adjust the start of their uplink frame (relative to the their downlink frame reference) by a round-trip delay (RTD) between the F-BS and M-BS (2xDl). Effectively this would advance the uplink frame relative to the M-BS receive frame reference by an additional amount of 1 A RTD (Dl). Since the femto footprint and D3 may be small (e.g., 100 meters), D1-D2 and interference from M- MS may be received within a cyclic prefix (CP) of the F-BS Uplink frame boundary. Based on numbers in the table of FIG.
- RTD round-trip delay
- D3 + delay spread (DS) will be less than the cyclic prefix. It is also seen that a transmission by the F-MS may still arrive within the CP of the F-BS's frame boundary. The interference from the F-MS at the M-BS would be similarly aligned. In IEEE 802.16(e) embodiments, the synchronization accuracy imposed by IEEE 802.16(e) may further assure that any additional resulting offset would typically be accommodated within the cyclic prefix.
- FIG. 4 illustrates the advancement of frame boundaries in accordance with some embodiments.
- FIG. 4 illustrates an initial unadjusted downlink frame boundary 412, a frame boundary 402 of the higher-tier base station 102 (FIG. 1), and an adjusted uplink OFDMA frame boundary 414 of the lower-tier base station 112 (FIG. 1).
- the lower-tier base station 112 may advance its uplink OFDMA frame boundaries 414 to align the its uplink OFDMA frame boundaries 414 with uplink frame transmissions of the higher tier.
- the lower-tier base station 112 may also delay its downlink OFDMA frame boundaries, if necessary, to align its downlink OFDMA frame boundaries with downlink frame transmissions of the higher tier.
- the adjustment of the uplink OFDMA frame boundaries 414 may help ensure that the uplink transmissions of a higher-tier mobile station 104 are received within a cyclic prefix at the lower-tier base station 112 to reduce asynchronous interference at the lower-tier base station 112.
- the adjustment of the downlink OFDMA frame boundaries may help ensure that the downlink transmissions of the lower-tier base station 112 to the lower-tier mobile station 114 are received within a cyclic prefix at the higher-tier mobile station 104 to reduce
- the alignment of the uplink OFDMA frame boundaries at the lower-tier base station 112 with respect to an uplink frame boundary of the higher-tier may reduce asynchronous interference at the lower-tier base station 112 by helping to ensure that the uplink transmissions of higher-tier mobile station 104 are received within the cyclic prefix at the lower-tier base station 112.
- transmissions of the higher-tier mobile station 104 is synchronously received (i.e., the cyclic prefixes of the received symbols) at the lower-tier base station 112 and may be reduced by one or more synchronous interference mitigation techniques.
- the alignment of the downlink OFDMA frame boundaries at the lower-tier base station 112 with respect to a downlink frame boundary of the higher-tier helps reduce asynchronous interference at the higher-tier mobile station 104 by helping to ensure that the downlink transmissions of the lower-tier base station 112 are received within a cyclic prefix at the higher-tier mobile station 104.
- interference caused by the downlink transmissions of the lower-tier base station 112 is synchronously received (e.g., within the cyclic prefixes of the received symbols) at the higher-tier mobile station 104 and may be reduced by one or more synchronous interference mitigation techniques.
- asynchronous interference at both the lower-tier base station 112 and the higher-tier mobile station 104 may be reduced allowing both the lower-tier base station 112 and the higher-tier mobile station 104 to further reduce the effects of interference by performing one or more synchronous interference mitigation techniques.
- the alignment of frame boundaries may also reduce asynchronous
- Lower-tier mobile station 114 may initially set their frame boundaries based on the frame boundaries of the lower-tier base station 112 and may further adjust their frame boundaries as discussed in more detail below.
- the lower-tier base station 112 may determine the initial unadjusted downlink frame boundary 412 by performing an over-the-air (OTA) synchronization process with the higher-tier base station 102. Due to the OTA
- OTA over-the-air
- the initial downlink frame boundary 412 may be delayed by approximately one-half the RTD time 415 with respect to the frame boundary 402 of the higher-tier base station 102.
- the lower-tier base station 112 may advance its uplink OFDMA frame boundary 414 with respect to the initial downlink frame boundary 412 by an amount approximately equal to the RTD time 415.
- the RTD time 415 may refer to twice the time it takes a signal to propagate between the higher-tier base station 102 and the lower-tier base station 112 over distance Dl .
- the OTA synchronization process may be performed based on the reception of preambles transmitted by the higher-tier base station 102.
- the OTA synchronization process may also include performing initial ranging to determine the signal propagation delay and thus the RTD 415.
- the initial unadjusted downlink frame boundary 412 may be delayed with respect to the frame boundary 402 of the high-tier base station 102 due to the signal propagation time over distance Dl between the higher-tier base station 102 and the lower-tier base station 112.
- the lower-tier base station 112 may advance its uplink OFDMA frame boundaries 414 with respect to the initial downlink frame boundary 412 by approximately the RTD time 415.
- asynchronous interference may be reduced because an uplink transmission from the higher-tier mobile station 104 to the higher-tier base station 102 may arrive at the lower-tier base station 112 within the cyclic prefix of the frame boundary 414 of the lower-tier base station 112.
- an uplink frame transmitted from the higher-tier mobile station 104 may arrive within the cyclic prefix of an uplink frame of the lower-tier-tier base station 112.
- the lower-tier base station 112 may align its downlink OFDMA frame boundary substantially with the initial downlink frame boundary 412.
- the downlink OFDMA frame boundary of the lower-tier base station 112 may not need to be delayed with respect to initial downlink frame boundary 412 since the frame boundary 402 of the higher-tier base station 102 received at the lower-tier base station 112 is already delayed by one-half the RTD 414.
- the lower-tier mobile station 114 associated with the lower-tier base station 112 may communicate with an uplink frame boundary 416 advanced by the RTD time 415 between the lower-tier base station 112 and the higher-tier base station 102.
- the lower-tier mobile station 114 may further advance its uplink frame boundary 416 based on a round-trip-delay time between the lower-tier base station 112 and the lower-tier mobile station 114.
- the lower-tier base station 112 may provide offset information to the lower-tier mobile station 114 associated with the lower-tier base station 112 during ranging so that the uplink frame boundaries 416 of the lower-tier mobile station 114 are at least advanced by the RTD time 415 between the lower- tier base station and the higher-tier base station. In this way, a lower-tier mobile station 114 may be unaware that it is operating in a multi-tier network. During the ranging process, the lower-tier mobile station 114 may determine the RTD time to the lower-tier base station 112 for further advancing is uplink frame boundaries 416 as illustrated in FIG. 4. Other techniques for conveying the offset information to a lower-tier mobile station 114 may also be used. For example, the offset information may be broadcasted by the lower-tier base station 112, provided to the lower-tier mobile station 114 via higher- layer signaling, or provided over a backhaul communication path.
- the lower-tier base station 112 may determine an initial unadjusted downlink frame boundary based on timing information received from another source, such as over a backhaul network or from GPS satellites. In this case, the initial downlink frame boundary of the lower-tier base station 112 may be approximately aligned with the frame boundary 402 of the higher-tier base station 102. In these non-OTA embodiments, the lower-tier base station 112 may delay its downlink
- the lower-tier base station 112 may advance its uplink OFDMA frame boundary 414 with respect to the initial downlink frame boundary by an amount approximately equal to the signal propagation time (i.e., one-half the RTD time 415).
- the lower-tier base station 112 may be configured to perform a ranging process with the higher-tier base station 102 to determine a signal propagation time between the higher-tier base station 102 and the lower-tier base station 112. Similar to the OTA synchronization embodiments discussed above, in these non- OTA synchronization embodiments, a lower-tier base station 112 may provide offset information to its associated lower-tier mobile station 114 during ranging so that the uplink frame boundaries of the lower-tier mobile station 114 can be aligned with the uplink frame boundaries of the lower-tier base station 112 and further advanced based on a RTD time between the lower-tier base station 112 and the lower-tier mobile station 114.
- the initial frame boundary 412 may be substantially aligned with the frame boundary 402 of the higher-tier base station 102.
- a lower-tier base station In addition to reducing asynchronous interference, a lower-tier base station
- synchronous interference mitigation techniques may be performed to reduce the effects of synchronous interference resulting from transmissions of the higher tier being received within the cyclic prefix.
- strong interference i.e., from transmissions by either the higher-tier base station 102 and/or a higher-tier mobile station 104
- This may enhance system capability of the multi-tier OFDMA overlay network 100 and may help avoid the complexity and poor efficiency associated with interference management techniques for asynchronous interference.
- Synchronous interference may comprise interference that is caused by the framed transmissions that fall within the cyclic prefix.
- synchronous interference may comprise interference that is caused by the framed transmissions between the higher-tier base station 102 and one or more higher-tier mobile station 104 that fall within the cyclic prefix of frames received at the lower-tier base station 112.
- Synchronous interference includes transmissions within a non-orthogonal (i.e., the same) frequency spectrum that arrive within the cyclic prefix of a symbol.
- synchronous interference may result because both the higher-tier mobile station 104 and the lower-tier mobile station 114 may transmit different information within the same frame time period using the same frequency spectrum.
- Examples of synchronous interference mitigation techniques include various signal processing techniques, the use of smart antennas techniques for nulling and avoiding interference, the use of smart antennas at the receiver to cancel interference, as well radio resource management schemes that use orthogonal sets of resources between the different tiers. A vast number of interference management schemes may be used with the embodiments described herein.
- the radius (rl) of the higher-tier service area 103 may be at least ten times (1Ox) a radius (r2) of the lower-tier service area 113.
- Transmissions by the lower-tier base station 112 and the lower-tier mobile station 114 may be at a significantly lower power level (e.g., 10x lower) than respective transmissions by the higher-tier base station 102 and the higher-tier mobile station 104.
- the radius of the higher- tier service area 103 may range from 1000 meters to more than 3000 meters, however this is not a requirement as the radius of the higher-tier service area 103 may be as small as 500 meters.
- the radius of the lower-tier service area 113 may range from less than 50 meters to up to few hundred meters.
- a lower-tier base station 112 and a lower-tier mobile station 114 near the outer edges may benefit by adjusting their OFDMA frame boundaries as described herein.
- a lower-tier base station 112 and a lower-tier mobile station 114 operating in the central portion of the higher-tier service area 103 may not experience significant asynchronous interference from the higher tier and may not need to adjust their OFDMA frame boundaries as described herein.
- a lower-tier base station 112 and a lower-tier mobile station 114 operating in about half of the higher-tier service area 103 would experience asynchronous interference and may benefit by adjusting their OFDMA frame boundaries as described herein.
- a lower-tier base station 112 may determine whether to adjust its OFDMA frame boundaries as described herein based on whether or not asynchronous interference would result due to timing misalignment exceeding the cyclic prefix.
- a lower-tier base station 112 may determine whether to adjust its OFDMA frame boundaries based on the length of the cyclic prefix and the distance to the higher-tier base station. In some other embodiments, a lower-tier base station 112 may adjust its OFDMA frame boundaries as described herein regardless of whether asynchronous interference would result.
- a lower-tier base station 112 is configured to adjust its OFDMA frame boundaries as described herein when the radius of the higher-tier service area 103 exceed a predetermined cyclic prefix size (e.g., of 1/8 symbol).
- the lower-tier base station 112 may refrain from adjusting its OFDMA frame boundaries when the radius of the higher-tier service area 103 does not exceed a predetermined value.
- a lower-tier base station 112 may adjust its OFDMA frame boundaries when the radius of a higher-tier service area 103 exceeds a predetermined value and may refrain from adjusting its OFDMA frame boundaries when the radius of the higher-tier service area 103 does not exceed a predetermined value.
- the lower-tier base station 112 may adjust its OFDMA frame boundaries when asynchronous interference would result based on a distance to the higher-tier base station 102 and a length of the cyclic prefix.
- the lower-tier base station 112 as well as the higher-tier base station 102 may operate in accordance with an IEEE 802.16 standard, such as the advanced air interface protocol defined in an IEEE 802.16(m), entitled “Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems".
- the higher-tier base station 102 may be an advanced base station (ABS) and the higher-tier mobile station 104 may be an advanced mobile station (AMS) that operate in accordance with the advanced air interface protocol defined in an IEEE 802.16(m).
- the lower-tier base station 112 may be a femto ABS with substantially lower transmit power than the higher-tier base station 102.
- the lower-tier base station 112 may be installed within a home, an office or other location to provide access to a local group of users with a femto service area.
- the lower-tier base station 112 may operate as a base station for the local group of users and may be connected to a service provider through a broadband connection.
- the elements of network 100 may be configured in accordance with one of the 3 GPP-LTE standards, such as the LTE advanced.
- a lower-tier base station 112 may communicate
- OFDMA frames with lower-tier mobile stations in accordance with an OFDMA time-division duplexed (TDD) communication technique comprising downlink subframes and uplink subframes that are communicated in TDD manner.
- network 100 may be configured in accordance with a TDD mode of WiMAX or 3GPP-LTE.
- uplink subframes may comprise single carrier SC communication signals instead of multicarrier OFDM signals.
- the lower-tier base station 112 may communicate
- OFDMA frames with lower-tier mobile stations in accordance with an OFDMA frequency- division duplexed (FDD) communication technique comprising downlink frames and uplink frames that are communicated in a FDD manner.
- FDD frequency- division duplexed
- network 100 may be configured in accordance with a FDD mode of WiMAX or 3GPP-LTE.
- the uplink and downlink frames may be communicated simultaneously.
- FIG. 5 is a block diagram of a base station in accordance with some embodiments.
- Base station 500 may be suitable for use as lower-tier base station 112 (FIG. 1).
- Base station 500 may include physical (PHY) layer circuitry 502 for communicating with one or more mobile stations, such as lower-tier mobile station 114 (FIG. 1), utilizing one or more antennas 501.
- Base station 500 may also include media-access control (MAC) layer circuitry 504 for performing MAC layer operations, and signal processing circuitry 506 for performing operations described herein.
- Base station 500 may also include interface circuitry 508 to interface with a broadband connection to a service provider to allow base station to independently provide service to mobile stations within its service area.
- PHY physical
- MAC media-access control
- signal processing circuitry 506 may cause
- Signal processing circuitry 506 may be configured to process signals, including signals received from a higher- tier base station and to determine the amount to adjust OFDMA frame boundaries as described herein.
- processing circuitry 506 may be configured to process signals received from a higher-tier base station to determine an initial frame boundary.
- signals may be received over the broadband connection for determining the initial unadjusted downlink frame boundary.
- base station 500 may include a GPS receiver to receive GPS signals for determining the initial unadjusted downlink frame boundary.
- base station 500 may operate in accordance with the parameters illustrated in FIG. 3 A, including an FFT size of 1024 and a cyclic prefix of 1/8.
- Antenna 501 may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of RF signals.
- antennas 501 may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result between each of antennas 501 and one or more antennas of a mobile station.
- base station 500 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements.
- processing elements including digital signal processors (DSPs), and/or other hardware elements.
- DSPs digital signal processors
- some elements may comprise one or more microprocessors, DSPs, application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein.
- the functional elements of the base station 500 may refer to one or more processes operating on one or more processing elements.
- FIG. 6 illustrates a procedure to reduce asynchronous interference in a multi- tier OFDMA overlay network in accordance with some embodiments.
- Procedure 600 may be performed by a base station that is operating at a lower-tier in a multi-tier OFDMA overlay network, such as lower-tier base station 112 (FIG. 1).
- the lower-tier base station determines an initial unadjusted downlink frame boundary.
- the initial unadjusted downlink frame boundary may be determined based on an OTA synchronization process or a non-OTA synchronization process described above.
- uplink OFDMA frame boundaries 414 may be advanced to align the uplink OFDMA frame boundaries 414 with uplink frame transmissions of the higher tier.
- downlink OFDMA frame boundaries may be delayed, if necessary, to align the downlink OFDMA frame boundaries with downlink frame
- offset information may be provided to lower-tier mobile stations associated with the lower-tier base station during ranging to allow a lower- tier mobile station to advance an uplink frame boundary 416 (FIG. 4) by a round-trip delay time between the lower-tier base station and the higher-tier base station.
- the adjustment of the uplink OFDMA frame boundaries in operation 604 may help ensure that the uplink transmissions of the higher-tier mobile station are received within a cyclic prefix at the lower-tier base station to reduce asynchronous interference at the lower- tier base station.
- the adjustment of the downlink OFDMA frame boundaries in operation 608 may help ensure that the downlink transmissions of the lower-tier base station to a lower-tier mobile station are received within a cyclic prefix at the higher-tier mobile station to reduce asynchronous interference at the higher-tier mobile station.
- procedure 600 Although the individual operations of procedure 600 are illustrated and described as separate operations, one or more of the individual operations may be performed concurrently, and nothing requires that the operations be performed in the order illustrated.
- the downlink frame boundaries may be adjusted followed the offset information being provided to a lower-tier mobile stations, and followed by adjustment of the uplink frame boundaries.
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Abstract
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US12/822,925 US8630229B2 (en) | 2009-07-06 | 2010-06-24 | Base station and method for reducing asynchronous interference in a multi-tier OFDMA overlay network |
TW099122032A TWI493936B (en) | 2009-07-06 | 2010-07-05 | Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network |
KR1020127003151A KR101454977B1 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network |
CN201080030491.4A CN102474487B (en) | 2009-07-06 | 2010-07-06 | For reducing base station and the method for the asynchronous interference in multilamellar ofdma overlay network |
RU2012103390/07A RU2501175C2 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in multi-tier ofdma overlay network |
JP2012519656A JP5540439B2 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in a multi-layer OFDMA overlay network |
PCT/US2010/041017 WO2011005727A2 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network |
EP10797700.1A EP2452475A4 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network |
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PCT/US2010/041017 WO2011005727A2 (en) | 2009-07-06 | 2010-07-06 | Base station and method for reducing asynchronous interference in a multi-tier ofdma overlay network |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8630229B2 (en) | 2009-07-06 | 2014-01-14 | Intel Corporation | Base station and method for reducing asynchronous interference in a multi-tier OFDMA overlay network |
EP2704463A1 (en) * | 2011-05-31 | 2014-03-05 | Huawei Technologies Co., Ltd | Data transmission method and device |
CN104322131A (en) * | 2012-05-21 | 2015-01-28 | 华为技术有限公司 | Uplink signal detecting method and relevant device and system |
EP2929739A4 (en) * | 2012-12-10 | 2016-07-27 | Qualcomm Inc | Method and apparatus for timing advance selection for synchronized uplink transmission |
RU2737389C2 (en) * | 2016-08-11 | 2020-11-30 | Шарп Кабусики Кайся | Systems and methods for operation with transmission time interval during duplex transmission with frequency division multiplexing |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7742738B2 (en) | 2006-12-27 | 2010-06-22 | Nortel Networks Limited | Method and system for diversity using orthogonal frequency/division multiplexing |
TWI463898B (en) * | 2010-01-08 | 2014-12-01 | Mediatek Inc | Uplink synchronization method,mobile station and base station |
EP2560428A4 (en) * | 2010-04-16 | 2016-12-28 | Kyocera Corp | Wireless communication system, high-power base station, low-power base station and communication control method |
EP2604055B1 (en) * | 2010-08-13 | 2018-07-25 | Telefonaktiebolaget LM Ericsson (publ) | Automatic guard period adjustment in time division duplexed wireless communication |
WO2012148336A1 (en) * | 2011-04-29 | 2012-11-01 | Telefonaktiebolaget L M Ericsson (Publ) | Decentralised control of interference reduction in a wireless communication system |
EP2742748A4 (en) * | 2011-08-12 | 2015-08-26 | Intel Corp | System and method of uplink power control in a wireless communication system |
EP3046301A1 (en) * | 2011-11-04 | 2016-07-20 | Intel Corporation | Timing synchronization for downlink (dl) transmissions in coordinated multipoint (comp) systems |
KR101670898B1 (en) * | 2012-04-18 | 2016-10-31 | 퀄컴 인코포레이티드 | Multi-radio coexistence |
EP2923472B1 (en) * | 2012-11-23 | 2020-01-08 | Telefonaktiebolaget LM Ericsson (publ) | Methods and apparatuses for radio resource management |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080107200A1 (en) * | 2006-11-07 | 2008-05-08 | Telecis Wireless, Inc. | Preamble detection and synchronization in OFDMA wireless communication systems |
US20090022098A1 (en) * | 2005-10-21 | 2009-01-22 | Robert Novak | Multiplexing schemes for ofdma |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9923070D0 (en) * | 1999-09-29 | 1999-12-01 | Nokia Telecommunications Oy | Multilayer telecommunications network |
UA90451C2 (en) * | 2003-05-12 | 2010-05-11 | Квелкомм Инкорпорейтед | Soft handoff with interferences damping in a communication wireless system with frequency hopping |
IL167628A (en) * | 2004-06-04 | 2010-11-30 | Optier Ltd | System and method for performance management in a multi-tier computing environment |
US8014781B2 (en) * | 2004-06-08 | 2011-09-06 | Qualcomm Incorporated | Intra-cell common reuse for a wireless communications system |
US8891349B2 (en) * | 2004-07-23 | 2014-11-18 | Qualcomm Incorporated | Method of optimizing portions of a frame |
AU2007265602B2 (en) * | 2006-06-23 | 2010-10-14 | Bae Systems Information And Electronic Systems Integration Inc. | Supporting mobile ad-hoc network (MANET) and point to multi-point (PMP) communications among nodes in a wireless network |
US7924728B2 (en) * | 2006-08-25 | 2011-04-12 | Raytheon Bbn Technologies Corp | Systems and methods for energy-conscious communication in wireless ad-hoc networks |
CN101174874A (en) * | 2006-11-03 | 2008-05-07 | 富士通株式会社 | Centralized-scheduler relay station for MMR extended 802.16E system |
US7742738B2 (en) * | 2006-12-27 | 2010-06-22 | Nortel Networks Limited | Method and system for diversity using orthogonal frequency/division multiplexing |
JP4879100B2 (en) | 2007-06-26 | 2012-02-15 | 株式会社エヌ・ティ・ティ・ドコモ | Mobile communication system, mobile communication method, and base station |
US20100208720A1 (en) | 2007-10-09 | 2010-08-19 | Hitachi, Ltd. | Wireless communication system, inter-base-station synchronization method and base station |
BRPI0818547A2 (en) * | 2007-10-17 | 2015-06-16 | Zte Usa Inc | Ofdm / ofdma frame structure for communications systems |
KR101632080B1 (en) * | 2007-11-09 | 2016-06-20 | 지티이 (유에스에이) 인크. | Flexible ofdm/ofdma frame structure for communication systems |
US8594576B2 (en) * | 2008-03-28 | 2013-11-26 | Qualcomm Incorporated | Short-term interference mitigation in an asynchronous wireless network |
US20090245409A1 (en) * | 2008-03-28 | 2009-10-01 | Qualcomm Incorporated | Apparatus, methods, and articles of manufacture for adaptive power control |
US8462765B2 (en) * | 2008-08-20 | 2013-06-11 | Qualcomm Incorporated | Method and apparatus to perform ranging operations for wireless stations |
US8665736B2 (en) * | 2009-02-27 | 2014-03-04 | Intel Corporation | MAC slot alignment among multiple wireless stations |
US8886205B2 (en) * | 2009-03-02 | 2014-11-11 | Qualcomm Incorporated | Timing adjustment for synchronous operation in a wireless network |
US8630229B2 (en) | 2009-07-06 | 2014-01-14 | Intel Corporation | Base station and method for reducing asynchronous interference in a multi-tier OFDMA overlay network |
-
2010
- 2010-06-24 US US12/822,925 patent/US8630229B2/en active Active
- 2010-07-05 TW TW099122032A patent/TWI493936B/en not_active IP Right Cessation
- 2010-07-06 WO PCT/US2010/041017 patent/WO2011005727A2/en active Application Filing
- 2010-07-06 JP JP2012519656A patent/JP5540439B2/en not_active Expired - Fee Related
- 2010-07-06 KR KR1020127003151A patent/KR101454977B1/en not_active IP Right Cessation
- 2010-07-06 CN CN201080030491.4A patent/CN102474487B/en active Active
- 2010-07-06 EP EP10797700.1A patent/EP2452475A4/en not_active Withdrawn
- 2010-07-06 RU RU2012103390/07A patent/RU2501175C2/en not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090022098A1 (en) * | 2005-10-21 | 2009-01-22 | Robert Novak | Multiplexing schemes for ofdma |
US20080107200A1 (en) * | 2006-11-07 | 2008-05-08 | Telecis Wireless, Inc. | Preamble detection and synchronization in OFDMA wireless communication systems |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8630229B2 (en) | 2009-07-06 | 2014-01-14 | Intel Corporation | Base station and method for reducing asynchronous interference in a multi-tier OFDMA overlay network |
EP2704463A1 (en) * | 2011-05-31 | 2014-03-05 | Huawei Technologies Co., Ltd | Data transmission method and device |
EP2704463A4 (en) * | 2011-05-31 | 2014-05-14 | Huawei Tech Co Ltd | Data transmission method and device |
US9148271B2 (en) | 2011-05-31 | 2015-09-29 | Huawei Technologies Co., Ltd. | Methods and devices for transmitting data |
US9474065B2 (en) | 2011-05-31 | 2016-10-18 | Huawei Technologies Co., Ltd. | Methods and devices for transmitting data |
CN104322131A (en) * | 2012-05-21 | 2015-01-28 | 华为技术有限公司 | Uplink signal detecting method and relevant device and system |
JP2015520998A (en) * | 2012-05-21 | 2015-07-23 | ▲ホア▼▲ウェイ▼技術有限公司 | Method and associated devices and systems for detecting uplink signals |
EP2840853A4 (en) * | 2012-05-21 | 2015-11-04 | Huawei Tech Co Ltd | Uplink signal detecting method and relevant device and system |
US9681346B2 (en) | 2012-05-21 | 2017-06-13 | Huawei Technologies Co., Ltd. | Method for detecting uplink signal and relevant device and system |
US10341913B2 (en) | 2012-05-21 | 2019-07-02 | Huawei Technologies Co., Ltd. | Method for detecting uplink signal and relevant device and system |
EP2929739A4 (en) * | 2012-12-10 | 2016-07-27 | Qualcomm Inc | Method and apparatus for timing advance selection for synchronized uplink transmission |
RU2737389C2 (en) * | 2016-08-11 | 2020-11-30 | Шарп Кабусики Кайся | Systems and methods for operation with transmission time interval during duplex transmission with frequency division multiplexing |
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TWI493936B (en) | 2015-07-21 |
EP2452475A4 (en) | 2017-03-22 |
CN102474487A (en) | 2012-05-23 |
EP2452475A2 (en) | 2012-05-16 |
WO2011005727A3 (en) | 2011-03-31 |
RU2012103390A (en) | 2013-08-20 |
RU2501175C2 (en) | 2013-12-10 |
TW201119306A (en) | 2011-06-01 |
US8630229B2 (en) | 2014-01-14 |
KR101454977B1 (en) | 2014-10-27 |
JP5540439B2 (en) | 2014-07-02 |
CN102474487B (en) | 2016-07-27 |
JP2012532573A (en) | 2012-12-13 |
KR20120042930A (en) | 2012-05-03 |
US20110002270A1 (en) | 2011-01-06 |
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