KR101310721B1 - Adaptive transmission (tx)/reception (rx) pulse shaping filter for femtocell base stations and mobile stations within a network - Google Patents

Abstract

The mobile station may include a standard transmit pulse-forming filter, a standard receive pulse-forming filter, a narrow transmit pulse-forming filter, and a narrow receive pulse-forming filter. The femtocell base station may include a narrow transmit pulse-forming filter and a narrow receive pulse-forming filter. The mobile station may utilize a narrow transmit pulse-forming filter for receiving uplink signals and a narrow receive pulse-forming filter for receiving downlink signals when it is receiving service from a femtocell base station. The mobile station may utilize a standard transmit pulse-forming filter for receiving uplink signals and a standard receive pulse-forming filter for receiving downlink signals when it is receiving service from the macrocell base station.

Description

ADAPTIVE TRANSMISSION (TX) / RECEPTION (RX) PULSE SHAPING FILTER FOR FEMTOCELL BASE STATIONS AND MOBILE STATIONS WITHIN A NETWORK}

This application claims priority to US Provisional Application No. 61 / 090,569, filed Aug. 20, 2008, entitled "Adaptive Transmission (Tx) / Reception (Rx) Pulse Shaping Filter For Access Point Base Stations and Mobile Stations Within A Network}. This provisional application is hereby incorporated by reference.

The present disclosure relates generally to communication systems. In particular, the present disclosure relates to an adaptive transmit (Tx) / receive (Rx) pulse shaping filter for femtocell base stations and mobile stations in a network.

Wireless communication systems have become an important means of communicating with many people around the world. The wireless communication system can provide communication for multiple mobile stations, each of which can be serviced by a base station.

As used herein, the term “mobile station” refers to an electronic device that can be used for voice and / or data communication via a wireless communication system. Examples of mobile stations include cellular telephones, personal digital assistants (PDAs), wireless modems, laptop computers, and the like. A mobile station may alternatively be referred to as an access terminal, mobile terminal, subscriber station, remote station, user terminal, terminal, subscriber unit, mobile device, wireless device, user equipment, or any other terminology.

The term "base station" refers to a wireless communication station installed in a fixed location and used to communicate with mobile stations. A base station may alternatively be referred to as an access point, Node B, evolved Node B, or any other similar term.

The mobile station can communicate with one or more base stations via transmissions on the uplink and downlink. The uplink (or reverse link) refers to the communication link from the mobile station to the base station, and the downlink (or forward link) refers to the communication link from the base station to the mobile station.

A femtocell base station is a small cellular base station typically designed for use in residential or small business environments. The femtocell base station connects to the service provider's network over a broadband (such as a DSL or cable). A femtocell base station allows service providers to extend service coverage rooms, particularly where access is limited or unavailable. The femtocell base station may alternatively be referred to as an access point base station, home node B (HNB), home evolved node B (HeNB), femto node, or the like.

The coverage area of the femtocell base station may be referred to herein as a femtocell. The coverage area of a typical base station may be referred to as a macrocell, and a typical base station may be referred to herein as a macrocell base station.

Adjacent channel interference is interference caused by irrelevant power from signals in adjacent channels. Adjacent channel interference can occur between two mobile stations, where one of the mobile stations receives service from a femtocell base station, the other mobile station receives service from a macrocell base station, and the two mobile stations operate on adjacent carriers and have. The present disclosure is particularly directed to reducing adjacent channel interference where interfering channels involve a femtocell base station and a macrocell base station.

1 illustrates a wireless communication system configured to support a number of users.
2 illustrates a wireless communication system including a femtocell base station and a macrocell base station.
3 illustrates a wireless communication system including a first mobile station and a second mobile station, in which adjacent channel interference may occur.
4 illustrates a transmitter and receiver in a wireless communication system.
5 and 6 illustrate a system where a femto base station utilizes a narrow transmit pulse-forming filter while a macrocell base station in the system utilizes a standard transmit pulse-forming filter.
FIG. 7 illustrates a method that may be performed by a mobile station in the systems of FIGS. 5 and 6 when the mobile station detects that a handoff from a macrocell base station to a femtocell base station has occurred.
FIG. 8 illustrates a method that may be performed by a mobile station in the systems of FIGS. 5 and 6 when the mobile station detects that a handoff from a femtocell base station to a macrocell base station has occurred.
9 illustrates means + functional blocks corresponding to the method of FIG. 7.
10 illustrates means + functional blocks corresponding to the method of FIG. 8.
FIG. 11 illustrates another system in which a macrocell base station in a system utilizes a standard transmit pulse-forming filter while a femtocell base station utilizes a narrow transmit pulse-forming filter, while a first mobile station and a second mobile station are located in a femtocell. .
12 illustrates certain components that may be included within a wireless device.

A femtocell base station configured to limit adjacent channel interference is disclosed. The femtocell base station includes a transmitter for transmitting downlink signals to a first mobile station. The first mobile station is located in the femtocell. The femtocell base station also includes a narrower transmit pulse-shaping filter. The narrow transmit pulse-forming filter is configured such that the bandwidth of the downlink signals transmitted by the femtocell base station is less than the bandwidth of the downlink signals transmitted by the macrocell base station to the second mobile station.

The femtocell base station may also include a receiver for receiving uplink signals from the first mobile station. The femtocell base station may also include a narrow receive pulse-forming filter that matches the narrow transmit pulse-forming filter of the first mobile station. The narrow transmit pulse-forming filter of the first mobile station may be configured such that the bandwidth of the uplink signals transmitted by the first mobile station is less than the bandwidth of the uplink signals transmitted by the second mobile station to the macrocell base station.

As mentioned, the femtocell base station includes a narrow transmit pulse-forming filter. The narrow receive pulse-forming filter of the first mobile station may be matched with the narrow transmit pulse-forming filter of the femtocell base station.

The macro cell base station may cover the macro cell. The femtocell may be located in the macrocell. A second mobile station may also be located within the femtocell.

A mobile station is configured that is configured to limit adjacent channel interference. The mobile station includes a transmitter for transmitting uplink signals. The mobile station also includes a transmit pulse-shaping filter that limits the bandwidth of the uplink signals transmitted by the mobile station. The mobile station also includes a narrow transmit pulse-forming filter that limits the bandwidth of uplink signals transmitted by the mobile station to a greater extent than the transmit pulse-forming filter.

The mobile station may also include a switching mechanism for switching between the transmit pulse-forming filter and the narrow transmit pulse-forming filter. As an example, the switching mechanism may be configured to switch from the transmit pulse-forming filter to the narrow transmit pulse-forming filter in response to detecting that a handoff from the macrocell base station to the femtocell base station has occurred. The switching mechanism may be configured to switch from the narrow transmit pulse-forming filter to the transmit pulse-forming filter in response to detecting that a handoff from the femtocell base station to the macrocell base station has occurred. Of course, other switching mechanisms are also possible within the scope of the present invention.

The mobile station may further comprise a receiver for receiving downlink signals. The mobile station may also include a receive pulse-forming filter that matches the transmit pulse-forming filter of the macrocell base station. The mobile station may also include a narrow receive pulse-forming filter that matches the narrow transmit pulse-forming filter of the femtocell base station. The mobile station may further include a switching mechanism for switching between the receive pulse-forming filter and the narrow receive pulse-forming filter. As an example, the switching mechanism may be configured to switch from the receive pulse-forming filter to the narrow receive pulse-forming filter in response to detecting that a handoff from the macrocell base station to the femtocell base station has occurred. The switching mechanism may be configured to switch from the narrow receive pulse-forming filter to the receive pulse-forming filter in response to detecting that a handoff from the femtocell base station to the macrocell base station has occurred. Of course, other switching mechanisms are possible within the scope of the present invention.

A method for increasing the signal-to-noise ratio (SNR) for a received signal and limiting adjacent uplink channel interference is disclosed. The method is implemented by a mobile station. The method includes detecting that a handoff from the macrocell base station to the femtocell base station has occurred. The method also includes switching from the receive pulse-forming filter to the narrow receive pulse-forming filter. The method also includes using a narrow receive pulse-forming filter to receive downlink transmissions from the femtocell base station.

The method may also include switching from a transmit pulse-forming filter to a narrow transmit pulse-forming filter. The method may also further include using a narrow transmit pulse-shaping filter to transmit the uplink transmissions to the femtocell base station.

The method may further comprise detecting that a handoff from the femtocell base station to the macrocell base station has occurred. The method may also include switching from a narrow receive pulse-forming filter to a receive pulse-forming filter. The method may also include using a receive pulse-shaping filter to receive downlink transmissions from the macrocell base station. The method may also include switching from a narrow transmit pulse-forming filter to a transmit pulse-forming filter. The method may also further comprise using a transmit pulse-shaping filter to transmit uplink transmissions to the macrocell base station.

An apparatus is disclosed that is configured to increase the signal-to-noise ratio (SNR) for a received signal and to limit adjacent uplink channel interference. The apparatus includes means for detecting that a handoff from the macrocell base station to the femtocell base station has occurred. The apparatus also includes means for switching from the receive pulse-forming filter to the narrow receive pulse-forming filter. The apparatus also includes means for using a narrow receive pulse-forming filter to receive downlink transmissions from a femtocell base station.

A computer-program product is disclosed for increasing the signal-to-noise ratio (SNR) for a received signal and for limiting adjacent uplink channel interference. The computer-program product includes a computer-readable medium having instructions. The instructions include code for detecting that a handoff from the macrocell base station to the femtocell base station has occurred. The instructions also include code for switching from the receive pulse-forming filter to the narrow receive pulse-forming filter. The instructions include code for using a narrow receive pulse-forming filter to receive downlink transmissions from a femtocell base station.

1 illustrates a wireless communication system 100 configured to support a number of users. System 100 provides communication for multiple macrocells 102 (eg, macrocells 120a-c), each macrocell 102 having a corresponding macrocell base station (BS) 104. (E.g., macrocell BSs 104a-c). Mobile stations 106 (eg, mobile stations 106a-n) may be distributed at various locations throughout the system 100 over time. Each mobile station (MS) 106 is associated with one or more macrocell base stations 104, for example, via the uplink and / or downlink at a given moment, depending on whether the MS 106 is active and in soft handoff. Can communicate. The wireless communication system 100 can provide services for large geographic areas.

2 illustrates a wireless communication system 200 including a femtocell BS 210 and a macrocell BS 204. In this specification, the coverage area of femtocell BS 210 may be referred to as femtocell 208, while the coverage area of macrocell BS 204 may be referred to as macrocell 202. Macrocell 202 may be significantly larger than femtocell 208. For example, the radius of the macrocell 202 may be on the order of several kilometers, while the femtocell 208 may cover a home or small building. The femtocell 208 can be thought of as a small, isolated coverage area located within the macrocell 202.

The femtocell BS 210 may be coupled to the wide area network 218 (eg, the Internet) and the mobile operator core network 216 via a DSL router, cable modem, wireless link, or other connection means. Macrocell BS 204 may also be coupled to core network 216.

The MS 206 may receive the service from the femtocell BS 210 and may also receive the service from the macrocell BS 204. For example, femtocell BS 210 may provide service to MS 206 when MS 206 is located within femtocell 208. When the MS 206 moves out of the femtocell 208 but is still located within the macrocell 202, the macrocell BS 204 can provide service to the MS 206.

3 shows a wireless communication system 300 in which a first MS 306a and a second MS 306b are located in a femtocell 308 located in a macrocell 302. The first MS 306a is receiving a service from the femtocell BS 310. The first MS 306a transmits data to the femtocell BS 310 over the uplink 312a and receives data over the downlink 314a from the femtocell BS 310. However, even if the second MS 306b is located within the femtocell 308, the second MS 306b is receiving service from the macrocell BS 304. For example, femtocell BS 310 may be located in a person's home and the second MS 306b may belong to someone who is visiting the person's home but is not authorized to receive service from the femtocell BS 310. have. The second MS 306b sends data to the macrocell BS 304 via the uplink 312b and receives data from the macrocell BS 304 via the downlink 314b.

The second MS 306b may be located relatively close to the femtocell BS 310. As a result, transmissions from the second MS 306b to the macrocell BS 304 on the uplink 312b may be received at the femtocell BS 310 and thus on the first MS 306a via the uplink 312a. ) May interfere with transmissions to the femtocell BS 310. If adjacent carriers are used for uplink 312a, this interference may be referred to as adjacent uplink channel interference.

Similarly, transmissions from femtocell BS 310 to first MS 306a over downlink 314a may be received at second MS 306b, and thus macrocell BS 304 over downlink 314b. ) May interfere with transmissions to the second MS 306b. If adjacent carriers are used for downlinks 314a and 314b, this interference may be referred to as adjacent downlink channel interference.

Although the second MS 306b in FIG. 3 is located within the femtocell 308, the adjacent uplink channel interference and the adjacent downlink channel interference may occur even if the second MS 306b is located outside the femtocell 308. May occur. The methods disclosed herein may be utilized whether the second MS 306b is inside or outside the femtocell 308.

4 illustrates a transmitter 420 and a receiver 422 of a wireless communication system 400. Transmitter 420 accepts digital data, converts it into a modulated radio frequency (RF) signal, and transmits the signal to receiver 422. The receiver 422 receives the RF signal and demodulates it to reproduce the data.

Digital data provided to the transmitter 420 may be modulated by the modulator 424 to produce a sequence of modulated samples representing symbols according to a particular modulation format. The modulated samples may be filtered by the transmitter (Tx) pulse-shaping filter 426 to produce a sequence of filtered samples. Tx pulse-forming filter 426 is a digital filter, which may be implemented as a finite impulse response (FIR) filter.

The Tx front end 428 may process the output of the Tx pulse-forming filter 426. Tx front end 428 may perform functions such as interpolation, predistortion, and / or other filtering operations. Filtered samples may be provided to a digital-to-analog converter (DAC) 430, which, as its own input, generates an analog signal representing the filtered and filtered sample sequence. The analog signal can then be upconverted to an appropriate radio frequency by an up converter (UC) 432 and amplified by a power amplifier (PA) 434. The RF signal can then be transmitted via the transmit antenna 436.

Receive antenna 438 may receive the transmitted signal and provide it to downconverter 440, which downconverts the signal from RF to the appropriate intermediate frequency (IF) or baseband analog signal. . The analog signal may be digitized by an analog-to-digital converter (ADC) 442, which produces a sequence of digitized samples. Digitized samples may be processed by a receiver (Rx) front end 444 that may perform functions such as decimation, automatic gain control (AGC), and / or other adaptive filtering operations. Next, the samples may be filtered by the Rx pulse-forming filter 446. Rx pulse-forming filter 446 is a digital filter that can be implemented as an FIR filter. Samples at the output of the Rx pulse-forming filter 446 may be demodulated by a demodulator 448 that generates and outputs data provided to the transmitter 420.

The spectral responses of Tx pulse-forming filter 426 and Rx pulse-forming filter 446 can have a significant impact on the performance of communication system 400. For example, the Tx pulse-forming filter 426 often limits the spectral bandwidth of the transmitted signal 423, which determines the level of adjacent channel interference and other spurious emissions generated by the transmitter 420. When the transmitter 420 conforms to a particular communication standard, the bandwidth of the transmitted signal is often specified in the standard using a spectral mask that should not be exceeded.

The Tx pulse-forming filter 426 and the Rx pulse-forming filter 446 must match each other. For example, the Tx pulse-forming filter 426 and Rx pulse-forming filter 446 are implemented such that each of them has a root raised cosine (RRC) response and their combined spectral response is a raised cosine (RC) spectral response. Can be. Of course, RRC is provided by way of example only; Tx pulse-forming filter 426 and Rx pulse-forming filter 446 need not be implemented such that each of them has an RRC response. However, the Tx pulse-forming filter 426 and the Rx pulse-forming filter 446 may cause the Rx pulse-forming filter 446 to maximize the signal-to-noise ratio (SNR). Must have the same response to match.

The femtocell BS 310, macrocell BS 304, and MSs 306a, 306b of the system 300 of FIG. 3 are configured similarly to the transmitter 420 and receiver 422 shown in FIG. 4. And a receiver, respectively.

5 and 6 illustrate one possible method for reducing adjacent channel interference of the type described above with respect to FIG. 3. In the illustrated manner, femtocell BS 510 in wireless communication system 500 utilizes a narrow Tx pulse-forming filter 550a while macrocell BS 504 in system 500 has a standard Tx pulse- The shaping filter 526a is utilized. The term "narrower" in this context limits the spectral bandwidth of the downlink 514b signals transmitted by the macrocell BS 504 by the Tx pulse-forming filter 550a utilized by the femtocell BS 510. Means limiting the downlink 514a signals transmitted by the femtocell BS 510 to a greater degree than the Tx pulse-forming filter 526a. For example, in one possible implementation, the 3 dB bandwidth of narrow Tx pulse-forming filter 550a may be 90% of the 3 dB bandwidth of standard Tx pulse-forming filter 526a. However, these values are provided by way of example only and should not be used to limit the scope of the invention.

The MS 506 in the system 500 is a narrow Rx pulse-forming filter 552b that matches the narrow Tx pulse-forming filter 550a of the femto BS 510 and the standard Tx pulse-forming of the macrocell BS 504. A standard Rx pulse-shaped filter 546b that matches the filter 526a.

MS 506 includes both narrow Tx pulse-forming filter 550b and standard Tx pulse-forming filter 526b. The narrow Tx pulse-forming filter 550a is transmitted by the MS 506 to a greater extent than the standard Tx pulse-forming filter 526b which limits the spectral bandwidth of the uplink 512b signals transmitted by the MS 506. Limit the spectral bandwidth of the uplink 512a signals. The femtocell BS 510 includes a narrow Rx pulse-forming filter 552a that matches the narrow Tx pulse-forming filter 550b of the MS 506. Macrocell BS 504 includes a standard Rx pulse-forming filter 546a that matches the standard Rx pulse-forming filter 546b of MS 506.

MS 506 may operate in at least two different configurations. In a first configuration, the MS 506 utilizes a narrow Tx pulse-forming filter 550b and a narrow Rx pulse-forming filter 552b. In a second configuration, the MS 506 utilizes a standard Tx pulse-forming filter 526b and a standard Rx pulse-forming filter 546b. The MS 506 also includes a switching mechanism 554 for switching between the first configuration and the second configuration.

5 illustrates that MS 506 is located within femtocell 508. MS 506 communicates with femtocell BS 510 via uplink 512a and downlink 514a. The MS 506 operates in the first configuration mentioned above, i.e., the MS 506 is a narrow Tx pulse-forming filter (matched with the narrow Rx pulse-forming filter 552a utilized by the femtocell BS 510). 550b and narrow Rx pulse-forming filter 552b (matched with narrow Tx pulse-forming filter 550a utilized by femtocell BS 510).

6 illustrates that MS 506 is outside of femtocell 508 but is still within macrocell 502. MS 506 communicates with macrocell BS 504 via uplink 512b and downlink 514b. MS 506 operates in the aforementioned second configuration, ie MS 506 is a standard Tx pulse-molded (matched with standard Rx pulse-shaped filter 546a utilized by macrocell BS 504). It utilizes filter 526b and standard Rx pulse-forming filter 546b (matched with standard Tx pulse-forming filter 526a utilized by macrocell BS 504).

In particular, referring to FIG. 7, when the MS 506 detects that a handoff from the macrocell BS 504 to the femtocell BS 510 has occurred (756), the MS 506 is a narrow Tx pulse-. Switching to shaping filter 550b may be made 758 and switching to narrow Rx pulse-shaping filter 552b 760. Next, the MS 506 may use 762 a narrow Tx pulse-forming filter 550b to transmit transmissions to the femtocell BS 510 via the uplink 512a and downlink (762) from the femtocell BS 510. Narrow Rx pulse-forming filter 552b may be used to receive transmissions via 514a (764).

Referring now to FIG. 8, when the MS 506 detects that a handoff from the femtocell BS 510 to the macrocell BS 504 has occurred (866), the MS 506 is standard Tx pulse-molded. Switch to filter 526b (868) and switch to standard Rx pulse-forming filter 546b (870). Next, the MS 506 can use a standard Tx pulse-forming filter 526b to transmit transmissions to the macrocell BS 504 via the uplink 512b (872) and from the macrocell BS 504 A standard Rx pulse-shaping filter 546b may be used 874 to receive transmissions on the downlink 514b.

In the previous discussion, the MS 506 detects that the MS 506 is served by the macrocell BS 504 or the femtocell BS 510 and the MS 506 automatically switches to the appropriate pulse-forming filters. Is assumed. Alternatively or additionally, when MS 506 is served by femtocell BS 510, femtocell BS 510 switches to narrow Tx pulse-forming filter 550b and narrow Rx pulse-forming filter 552b. Command MS 506 to do so.

The method 700 of FIG. 7 may be performed by various hardware and / or software component (s) and / or module (s) corresponding to the means + functional blocks 900 illustrated in FIG. 9. In other words, the blocks 756-764 illustrated in FIG. 7 correspond to the means + functional blocks 956-964 illustrated in FIG. 9.

Similarly, the method 800 of FIG. 8 may be performed by various hardware and / or software component (s) and / or module (s) corresponding to the means + functional blocks 1000 illustrated in FIG. 10. . In other words, the blocks 866-874 illustrated in FIG. 8 correspond to the means + functional blocks 1066-1074 illustrated in FIG. 10.

FIG. 11 illustrates a system 1100 similar to system 300 discussed above with respect to FIG. 3. In particular, FIG. 11 illustrates a system 1100 where a first MS 1106a and a second MS 1106b are located within a femtocell 1108 located within a macrocell 1102. Similar to the system 300 discussed above with respect to FIG. 3, the first MS 1106a is receiving a service from the femtocell BS 1110. The first MS 1106a transmits data to the femtocell BS 1110 via the uplink 1112a and receives data from the femtocell BS 1110 via the downlink 1114a. Although the second MS 1106b is located within the femtocell 1108, the second MS 1106b is receiving service from the macrocell BS 1104. The second MS 1106b transmits data to the macrocell BS 1104 via the uplink 1112b and receives data from the macrocell BS 1104 via the downlink 1114b.

In the system 300 discussed above in connection with FIG. 3, the femtocell BS 310, the macrocell BS 304, and the MSs 306a, 306b are each the same Tx pulse-forming filter 426 and the same Rx pulse- The shaping filter 446 is utilized. In contrast, in the system 1100 shown in FIG. 11, the femtocell BS 1110, macrocell BS 1104 and MSs 1106a, 1106b do not utilize the same Tx pulse-forming filter and the same Rx pulse-forming filter. Do not.

The femtocell BS 1110 utilizes a narrow Tx pulse-forming filter 1150a, while the macrocell BS 1104 utilizes a standard Tx pulse-forming filter 1126a. Narrow Tx pulse-forming filter 1150a is femtocell BS 1110 to a greater extent than standard Tx pulse-forming filter 1126a that limits the spectral bandwidth of downlink signals 1114b transmitted by macrocell BS 1104. Limits the spectral bandwidth of the downlink signals 1114a transmitted by the MCP. The first MS 1106a is a narrow Tx pulse-forming filter of the femtocell BS 1110 (used when the first MS 1106a is located within the femtocell 1108 and is receiving service from the femtocell BS 1110). A narrow Rx pulse-forming filter 1152b that matches 1150a, wherein the first MS 1106a is located outside the femtocell 1108 but is within the macrocell 1104 and services from the macrocell BS 1104 And a standard Rx pulse-forming filter 1146b that matches the standard Tx pulse-forming filter 1126a of the macrocell BS 1104). The second MS 1106b includes a standard Rx pulse-forming filter 1146b ′ that matches the standard Tx pulse-forming filter 1126a of the macrocell BS 1104.

The first MS 1106a is a narrow Tx pulse-forming filter 1150b (used when the first MS 1106a is located within the femtocell 1108 and is receiving service from the femtocell BS 1110) and the first MS. Utilizes a standard Tx pulse-forming filter 1126b, which is used when 1106a is located outside the femtocell 1108 but is receiving service from the macrocell BS 1104. Second MS 1106b includes a standard Tx pulse-forming filter 1126b '. Narrow Tx pulse-forming filter 1150b is more than standard Tx pulse-forming filter 1112b that limits the spectral bandwidth of the uplink signals transmitted by first MS 1106a or by a second MS 1106b. It limits the spectral bandwidth of the uplink 1112a signals transmitted by the first MS 1106a to a greater extent than the standard Tx pulse-forming filter 1126b 'which limits the spectral bandwidth of the transmitted uplink 1126b signals. The femtocell BS 1110 includes a narrow Rx pulse-forming filter 1152a that matches the narrow Tx pulse-forming filter 1150b of the first MS 1106a. The macrocell BS 1104 is a standard Rx pulse-forming filter that matches the standard Tx pulse-forming filter 1126b of the first MS 1106a and the standard Tx pulse-forming filter 1126b 'of the second MS 1106b. 1146a.

Like the system 300 described above with respect to FIG. 3, the second MS 1106b may be disposed relatively close to the femtocell BS 1110. As a result, transmissions from the second MS 1106b to the macrocell BS 1104 on the uplink 1112b may be received at the femtocell BS 1110 and thus the first MS 1106a on the uplink 1112a. May interfere with transmissions to the femtocell BS 1110. If adjacent carriers are used for uplinks 1112a and 1112b, this interference may be referred to as adjacent uplink channel interference. However, because the first MS 1106a utilizes a narrow Tx pulse-forming filter 1150b, the adjacent uplink channel interference occurring in the system 1100 of FIG. 11 may be adjacent to that occurring in the system 300 of FIG. It can be significantly less than uplink channel interference. The femtocell BS 1110 also utilizes a narrow Rx pulse-forming filter 1152a to increase the signal-to-noise ratio (SNR) for the received signal.

Similarly, transmissions from the femtocell BS 1110 to the first MS 1106a over the downlink 1114a may be received at the second MS 1106b and thus the macrocell BS 1104 over the downlink 1114b. ) May interfere with transmissions to the second MS 1106b. If adjacent carriers are used for downlinks 1114a and 1114b, this interference may be referred to as adjacent downlink channel interference. However, because the femtocell BS 1110 utilizes a narrow Tx pulse-forming filter 1150a, the adjacent downlink channel interference occurring in the system 1100 of FIG. 11 is caused by the adjacent downlink occurring in the system 300 of FIG. It can be significantly smaller than link channel interference. In addition, the first MS 1106a utilizes a narrow Rx pulse-forming filter 1152b to increase the SNR for the received signal.

12 illustrates certain components that may be included within the wireless device 1201. Wireless device 1201 may be a mobile station or a base station.

The wireless device 1201 includes a processor 1203. Processor 1203 may be a general purpose single or multi-chip microprocessor (eg, ARM), special purpose microprocessor (eg, digital signal processor (DSP)), microcontroller, programmable gate array, or the like. Processor 1203 may be referred to as a central processing unit (CPU). Although only a single processor 1203 is shown in the wireless device 1201 of FIG. 12, a combination of processors (eg, ARM and DSP) may be used in alternative configurations.

The wireless device 1201 also includes a memory 1205. Memory 1205 may be any electronic component capable of storing electronic information. Memory 1205 includes random access memory (RAM), read-only memory (ROM), magnetic disk storage media, optical storage media, flash memory devices in RAM, on-board memory including a processor, EPROM memory, EEPROM memory, registers And the like, and any combination thereof.

Data 1207 and instructions 1209 may be stored in memory 1205. The instructions 1209 may be executable by the processor 1203 to implement the methods disclosed herein. Executing instructions 1209 may involve the use of data 1207 stored in memory 1205. A certain amount of data 1207a and instructions 1209a may be loaded into the processor 1203.

The wireless device 1201 may also include a transmitter 1211 and a receiver 1213 that enable transmission and reception of signals between the wireless device 1201 and a remote location. Transmitter 1211 and receiver 1213 may be collectively referred to as transceiver 1215.

If the wireless device 1201 is a mobile station 506, the transmitter 1211 may include a narrow Tx pulse-forming filter 550b and a standard Tx pulse-forming filter 526b, and the receiver 1213 may have a narrow Rx. Pulse-forming filter 552b and standard Rx pulse-forming filter 546b. If the wireless device 1201 is a femtocell base station 510, the transmitter 1211 may include a narrow Tx pulse-forming filter 550a and the receiver 1213 includes a narrow Rx pulse-forming filter 552a. can do. If the wireless device 1201 is a macrocell base station 504, the transmitter 1211 may include a standard Tx pulse-forming filter 526a and the receiver 1213 may use a standard Rx pulse-forming filter 546a. It may include.

The antenna 1217 may be electrically connected to the transceiver 1215. The wireless device 1201 may also include (shown) multiple transmitters, multiple receivers, multiple transceivers, and / or multiple antennas.

Various components of wireless device 1201 may be coupled together by one or more buses, which may include a power bus, control signal bus, status signal bus, data bus, and the like. For clarity, various buses are illustrated in FIG. 12 as the bus system 1219.

The term "processor" should be interpreted broadly to include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. Under some circumstances, a “processor” may refer to an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), or the like. The term “processor” may refer to a combination of processing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other configuration.

The term "memory" should be construed broadly to include any electronic component capable of storing electronic information. The term memory refers to random access memory (RAM), read-only memory (PROM), nonvolatile random access memory (NVRAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable It may refer to various types of processor-readable media such as PROM (EEPROM), flash memory, magnetic or optical data storage, registers, and the like. If the processor can read information from and / or write information to the memory, the memory may be said to be in electronic communication with the processor. Memory integrated into the processor is in electronic communication with the processor.

The terms "instructions" and "code" should be broadly interpreted to encompass any type of computer-readable statement (s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, subroutines, functions, procedures, and the like. "Instructions" and "code" may include a single computer-readable statement or many computer-readable statements.

The functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions on a computer-readable medium. The term "computer-readable medium" refers to any available medium that can be accessed by a computer. By way of example and not limitation, computer-readable media may be any desired program in the form of RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or instructions or data structures. It can include any other medium that can be used to carry or store the code and can be accessed by a computer. The discs and discs used here include compact discs (CDs), laser discs, optical discs, DVDs, floppy discs, and Blu-ray discs where disc plays the data magnetically, As shown in FIG.

The software or commands may also be transmitted over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source via coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, such coaxial cable , Fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of such media.

The methods disclosed herein comprise one or more steps or actions for achieving the disclosed method. The method steps and / or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper implementation of the method being described, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

Furthermore, modules and / or other suitable means for performing the methods and techniques described herein, such as those described by FIGS. 7 and 8, may be downloaded by the device and / or otherwise obtained It should be understood that it can be. For example, the device may be connected to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein may include storage means (eg, random access memory (RAM), read only memory (ROM), Physical storage media such as a compact disk (CD) or floppy disk, or the like). In addition, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes, and variations may be made in the arrangement, operation, and details of the systems, methods, and apparatus described herein without departing from the scope of the claims.

Claims (30)

A femtocell base station configured to limit adjacent channel interference,
A transmitter for transmitting downlink signals to a first mobile station, the first mobile station located in a femtocell; And
Includes a narrower transmit pulse-shaping filter,
The narrow transmit pulse-forming filter is configured such that the bandwidth of the downlink signals transmitted by the femtocell base station is less than the bandwidth of the downlink signals transmitted by a macrocell base station to a second mobile station.
A femtocell base station configured to limit adjacent channel interference. The method of claim 1,
A receiver for receiving uplink signals from the first mobile station; And
A narrow receive pulse-forming filter matching the narrow transmit pulse-forming filter at the first mobile station
The femtocell base station further configured to limit adjacent channel interference. 3. The method of claim 2,
The narrow transmit pulse-forming filter at the first mobile station is configured such that the bandwidth of the uplink signals transmitted by the first mobile station is less than the bandwidth of uplink signals transmitted by the second mobile station to the macrocell base station. felled,
A femtocell base station configured to limit adjacent channel interference. The method of claim 1,
Wherein the narrow receive pulse-forming filter at the first mobile station is matched with the narrow transmit pulse-forming filter. The method of claim 1,
Wherein said macrocell base station covers a macrocell, said femtocell located within said macrocell, configured to limit adjacent channel interference. The method of claim 1,
And the second mobile station is further configured to limit adjacent channel interference located within the femtocell. A mobile station configured to limit adjacent channel interference, comprising:
A transmitter for transmitting uplink signals;
A transmit pulse-forming filter that limits the bandwidth of the uplink signals transmitted by the mobile station;
A narrow transmit pulse-forming filter that limits the bandwidth of the uplink signals transmitted by the mobile station to a greater extent than the transmit pulse-forming filter; And
A switching mechanism for switching between the transmit pulse-forming filter and the narrow transmit pulse-forming filter;
The switching mechanism is configured to switch from the transmit pulse-forming filter to the narrow transmit pulse-forming filter in response to detecting that a handoff from a macrocell base station to a femtocell base station has occurred.
A mobile station configured to limit adjacent channel interference. delete delete The method of claim 7, wherein
The switching mechanism is configured to switch from the narrow transmit pulse-forming filter to the transmit pulse-forming filter in response to detecting that a handoff from a femtocell base station to a macrocell base station has occurred.
A mobile station configured to limit adjacent channel interference. The method of claim 7, wherein
A receiver for receiving downlink signals;
A receive pulse-forming filter matching the transmit pulse-forming filter at the macrocell base station; And
Narrow receive pulse-forming filter matched to narrow transmit pulse-forming filter at femtocell base station
The mobile station further configured to limit adjacent channel interference. The method of claim 11,
Switching mechanism for switching between the receive pulse-forming filter and the narrow receive pulse-forming filter
The mobile station further configured to limit adjacent channel interference. 13. The method of claim 12,
The switching mechanism is configured to switch from the receive pulse-forming filter to the narrow receive pulse-forming filter in response to detecting that a handoff from the macrocell base station to the femtocell base station has occurred. Mobile station composed. 13. The method of claim 12,
And the switching mechanism is configured to switch from the narrow receive pulse-forming filter to the receive pulse-forming filter in response to detecting that a handoff from the femtocell base station has occurred to the macrocell base station. Mobile station composed. A method for increasing the signal-to-noise ratio (SNR) for a received signal and limiting adjacent uplink channel interference, the method comprising:
The method is implemented by a mobile station,
The method comprises:
Detecting that a handoff from the macrocell base station to the femtocell base station has occurred;
Switching from the receive pulse-forming filter to the narrow receive pulse-forming filter; And
Using the narrow receive pulse-forming filter to receive downlink transmissions from the femtocell base station;
Way. The method of claim 15,
The narrow receive pulse-forming filter matches a narrow transmit pulse-forming filter at the femtocell base station. The method of claim 15,
Switching from a transmit pulse-forming filter to a narrow transmit pulse-forming filter; And
Using the narrow transmit pulse-forming filter to transmit uplink transmissions to the femtocell base station.
≪ / RTI > The method of claim 17,
The narrow transmit pulse-forming filter limits the bandwidth of the uplink transmissions to a greater extent than the transmit pulse-forming filter. The method of claim 15,
Detecting that a handoff has occurred from the femtocell base station to the macrocell base station;
Switching from said narrow receive pulse-forming filter to said receive pulse-forming filter; And
Using the receive pulse-forming filter to receive downlink transmissions from the macrocell base station
≪ / RTI > The method of claim 19,
Switching from a narrow transmit pulse-forming filter to a transmit pulse-forming filter; And
Using the transmit pulse-forming filter to transmit uplink transmissions to the macrocell base station
≪ / RTI > An apparatus configured to increase a signal-to-noise ratio (SNR) for a received signal and to limit adjacent uplink channel interference, the apparatus comprising:
Means for detecting that a handoff from the macrocell base station to the femtocell base station has occurred;
Means for switching from the receive pulse-forming filter to the narrow receive pulse-forming filter; And
Means for using the narrow receive pulse-forming filter to receive downlink transmissions from the femtocell base station
/ RTI > 22. The method of claim 21,
And the narrow receive pulse-forming filter matches a narrow transmit pulse-forming filter at the femtocell base station. 22. The method of claim 21,
Means for switching from a transmit pulse-forming filter to a narrow transmit pulse-forming filter; And
Means for using the narrow transmit pulse-forming filter to transmit uplink transmissions to the femtocell base station
≪ / RTI > 24. The method of claim 23,
The narrow transmit pulse-forming filter limits the bandwidth of the uplink transmissions to a greater extent than the transmit pulse-forming filter. 22. The method of claim 21,
Means for detecting that a handoff has occurred from the femtocell base station to the macrocell base station;
Means for switching from said narrow receive pulse-forming filter to said receive pulse-forming filter; And
Means for using the receive pulse-forming filter to receive downlink transmissions from the macrocell base station
≪ / RTI > The method of claim 25,
Means for switching from a narrow transmit pulse-forming filter to a transmit pulse-forming filter; And
Means for using the transmit pulse-forming filter to transmit uplink transmissions to the macrocell base station
≪ / RTI > A computer-readable medium for increasing signal-to-noise ratio (SNR) for a received signal and for limiting adjacent uplink channel interference, comprising:
The instructions provided on the computer-readable medium may include
Code for detecting that a handoff from the macrocell base station to the femtocell base station has occurred;
Code for switching from the receive pulse-forming filter to the narrow receive pulse-forming filter; And
Code for using the narrow receive pulse-forming filter to receive downlink transmissions from the femtocell base station;
Computer-readable media. The method of claim 27,
Code for switching from a transmit pulse-forming filter to a narrow transmit pulse-forming filter; And
Code for using the narrow transmit pulse-forming filter to transmit uplink transmissions to the femtocell base station
Further comprising a computer-readable medium. The method of claim 27,
Code for detecting that a handoff has occurred from the femtocell base station to the macrocell base station;
Code for switching from the narrow receive pulse-forming filter to the receive pulse-forming filter; And
Code for using the receive pulse-forming filter to receive downlink transmissions from the macrocell base station
Further comprising a computer-readable medium. 30. The method of claim 29,
Code for switching from a narrow transmit pulse-forming filter to a transmit pulse-forming filter; And
Code for using the transmit pulse-forming filter to transmit uplink transmissions to the macrocell base station
Further comprising a computer-readable medium.

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