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CN1080979C - Cellular communication system and its semi-hard handover method - Google Patents

Cellular communication system and its semi-hard handover method Download PDF

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CN1080979C
CN1080979C CN94194906A CN94194906A CN1080979C CN 1080979 C CN1080979 C CN 1080979C CN 94194906 A CN94194906 A CN 94194906A CN 94194906 A CN94194906 A CN 94194906A CN 1080979 C CN1080979 C CN 1080979C
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mobile exchange
cdma
hard handover
base station
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CN1142881A (en
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帕特·马斯英斯金
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Nokia Oyj
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/06Reselecting a communication resource in the serving access point

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Abstract

In a CDMA cellular communication system including a Mobile Switch (MSC), a Base Station (BS) and a Mobile Station (MS), a new CDMA handoff method is used: a semi-hard handover. Semi-hard handovers occur in a border base station (BS12) located at the border of two service areas (SA1, SA2) controlled by two adjacent mobile exchanges (MSC1, MSC 2). The border base station is connected to both mobile exchanges, and is accessible from both mobile exchanges.

Description

蜂窝通信系统及其半硬切换方法Cellular communication system and its semi-hard handover method

本发明涉及蜂窝通信系统。特别是一种为移动站和基站之间切换而改进的新型系统,这些基站是连接在一个蜂窝通信系统中的不同移动交换中心上的。The present invention relates to cellular communication systems. In particular, a novel system is improved for handover between mobile stations and base stations connected to different mobile switching centers in a cellular communication system.

码分多址(CDMA)调制方式是若干种数字通信技术中的一种,这些技术用来使多个移动用户能够共同使用同一个无线频段,蜂窝通信系统就是这样。其它人们熟知的无线接入技术有时分多址(TDMA)和频分多址(FDMA)。与本发明紧密相关的软切换概念对上述三种多址接入技术确实非常适用,与常规硬切换方式相比,将会增加系统容量,减少漏失的呼叫。然而,在CDMA中必须使用软切换,因为常规硬切换会造成低劣的系统性能。本发明的背景是将其运用于一个CDMA蜂窝通信系统,但不应被理解为,本发明只限于CDMA。有一个将CDMA用于蜂窝通信系统的应用实例,在“将码分多址(CDMA)应用于数字蜂窝及个人通信网的系统设计”一文中对这个实例有详细描述,论文作者是Allen Salmasi和Klein S.Gilhousen.,发表于第41届IEEE移动技术会议,会议于1991年5月19-22日在密苏里州圣路易斯召开。Code Division Multiple Access (CDMA) modulation is one of several digital communication techniques used to enable multiple mobile users to share the same radio frequency band, such as cellular communication systems. Other well-known radio access techniques are Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). The concept of soft handover closely related to the present invention is very suitable for the above three multiple access technologies. Compared with conventional hard handover, the system capacity will be increased and missed calls will be reduced. However, soft handover must be used in CDMA because conventional hard handover results in poor system performance. The background of the present invention is its application to a CDMA cellular communication system, but it should not be construed that the present invention is limited to CDMA only. An example of the application of CDMA to a cellular communication system is described in detail in "Applying Code Division Multiple Access (CDMA) to System Design for Digital Cellular and Personal Communication Networks" by Allen Salmasi and Klein S. Gilhousen. Presented at the 41st IEEE Mobile Technology Conference, St. Louis, MO, May 19-22, 1991.

在上述论文中,描述了一种直接序列CDMA(DS-CDMA),下文简写为CDMA技术,利用这种技术一些用户移动站(MS)与基站(BS,或称为小区节点)用CDMA无线扩频信号,在上行链路(从移动站到基站)和下行链路(从基站到移动站)上进行通信。图1示出现有技术的一种典型的CDMA通信系统的网络配置。基站BS10,12,14,16将来自或传给用户移动站20的这些CDMA无线信号转换成能和地面通信传输设备,如广泛使用的脉冲编码调制(PCM)电路设备,相配合的适用形式的信号。基站接着把上、下行链路方向上的这些用户信号传递给移动交换中心1或2(MSC,又称为移动交换机或移动电话交换局(MTSO)),作进一步的处理。In the above paper, a direct sequence CDMA (DS-CDMA) is described, hereinafter abbreviated as CDMA technology. Using this technology, some user mobile stations (MS) and base stations (BS, or cell nodes) use CDMA wireless extension Frequency signals are communicated on the uplink (from mobile station to base station) and downlink (from base station to mobile station). FIG. 1 shows a network configuration of a typical CDMA communication system in the prior art. The base station BS10, 12, 14, 16 converts these CDMA radio signals from or to the subscriber mobile station 20 into suitable forms compatible with terrestrial communication transmission equipment, such as widely used pulse code modulation (PCM) circuit equipment. Signal. The base station then transfers these user signals in the uplink and downlink directions to a Mobile Switching Center 1 or 2 (MSC, also known as a Mobile Switch or Mobile Telephone Switching Office (MTSO)) for further processing.

上述用户通信信号包括数字化语音信号和控制信息(也称为信令)。MSC对上述支路进行复用和转换操作,并将语音信号传送给另一个用户,例如在公共交换电话网(PSTN)中的用户。MSC还生成信令信息,解释信令信息,并对信令信息作出反应,由此控制用户之间的全部通信链路。这些通信链路控制功能包括管理与一般呼叫有关的事件,如呼叫的建立和拆除,也包括管理与CDMA无线链路有关的事件,如CDMA无线链路品质的下降及接着发生的切换的开始。The above user communication signals include digitized voice signals and control information (also referred to as signaling). The MSC performs multiplexing and switching operations on the above-mentioned branches, and transmits the voice signal to another user, such as a user in the public switched telephone network (PSTN). The MSC also generates signaling information, interprets the signaling information, and reacts to the signaling information, thereby controlling the entire communication link between users. These communication link control functions include management of events related to general calls, such as call set-up and tear-down, as well as management of events related to the CDMA radio link, such as degradation of the quality of the CDMA radio link and the initiation of handovers that ensue.

如果CDMA应用于地面移动通信系统中典型的中、大型规模小区时,多路径无线传播环境里的传播平均延迟时间常常大于DS-CDMA信号的码片长度。这样使得CDMA只能在异步模式下工作,其结果是扩频多址接入用户信号的正交性无法仅通过正交扩频码获得。因此,影响通信的系统自身诱发的干扰不仅存在于来自不同小区的信号之中,还有相当一部分在同一小区的信号之内(称为CDMA小区内干扰)。对这样的CDMA蜂窝系统,在整体系统设计中的一个重要目标就是尽可能减少对在通信用户中产生额外的CDMA的干扰,并且,要尽可能接收和利用来自所要的CDMA用户信号中的能量。这种系统设计的要求,尽管对蜂窝通信系统的其它多址接入方式也是一个一般的要求,但对FDMA和TDMA系统,这一要求不如对CDMA那么严格,因为在这两种系统中,小区内干扰可以分别利用TDMA和FDMA的内在特性而得以避免,而且可利用预先计划的蜂窝式频率重复利用方法来加以限制。因此,与FDMA,TDMA不同,CDMA在严格限制干扰的方式下工作。If CDMA is applied to typical medium and large-scale cells in the ground mobile communication system, the average propagation delay time in the multipath wireless propagation environment is often greater than the chip length of the DS-CDMA signal. In this way, CDMA can only work in asynchronous mode. As a result, the orthogonality of spread spectrum multiple access user signals cannot be obtained only by orthogonal spread spectrum codes. Therefore, the interference induced by the system itself that affects communication not only exists in signals from different cells, but also has a considerable part in signals of the same cell (called CDMA intra-cell interference). For such a CDMA cellular system, an important goal in the overall system design is to reduce as much as possible the interference of additional CDMA in the communication users, and to receive and utilize the energy from the desired CDMA user signal as much as possible. Although this system design requirement is also a general requirement for other multiple access methods of cellular communication systems, it is not as strict as for CDMA for FDMA and TDMA systems, because in these two systems, the cell Interference can be avoided by exploiting the inherent characteristics of TDMA and FDMA respectively, and can be limited by pre-planned cellular frequency reuse methods. So, unlike FDMA, TDMA, CDMA works in a strictly limited interference manner.

虽然软切换也能够增加TDMA的系统容量,其效果却不如CDMA系统,下面以一个CDMA蜂窝电信系统为例来说明本发明。Although the soft handover can also increase the system capacity of TDMA, its effect is not as good as that of the CDMA system. The following uses a CDMA cellular telecommunication system as an example to illustrate the present invention.

有几种实现上述CDMA系统设计目标的方式,可以被认为是上述CDMA蜂窝电信系统的示例性实施例。例如,所谓的MS发射功率闭环控制方式,其目的在于使一个BS内收到的所有上行链路的信号质量始终保持一致,这是相对于具有快衰落和慢衰落过程的迅速变化的无线传播信道背景而言的。为此,基站周期地测量每一条MS的CDMA上行链路来的Eb/No值,这个值表明了信号的品质,然后通过下行链路发出相应的功率控制命令给MS,用来相应地调节其CDMA发射器的功率。在理想情况下,BS收到的所有MS的CDMA上行链路信号具有相同的品质,根据预先确定的品质门限值,只需最少的调节就可以维持通信链路。There are several ways of achieving the design goals of the above-described CDMA system, which can be considered as exemplary embodiments of the above-described CDMA cellular telecommunication system. For example, the so-called MS transmit power closed-loop control method aims to keep the signal quality of all uplinks received in a BS consistent, which is relative to the rapidly changing wireless propagation channel with fast fading and slow fading processes. background. To this end, the base station periodically measures the Eb/No value from the CDMA uplink of each MS. This value indicates the quality of the signal, and then sends a corresponding power control command to the MS through the downlink to adjust its power accordingly. The power of the CDMA transmitter. Ideally, all MS CDMA uplink signals received by the BS have the same quality, and according to a predetermined quality threshold, only a minimum of adjustments are required to maintain the communication link.

另一实现前述系统设计目的的实施例是在一个正在工作的CDMA通信过程中,结合信号分集合并的辅助移动软切换方式,这一与本发明密切相关的方法将在下面阐述。Another embodiment to achieve the above-mentioned system design purpose is in a working CDMA communication process, combined with the assisted mobile soft handover mode of signal diversity combining, this method closely related to the present invention will be described below.

结合信号分集合并的辅助移动软切换包括以下方法:在上行和下行链路上,经由第一和第二BS,MS和MSC之间的传输段上同时传递用户通信信号,在MS和MSC进行信号分集接收以提高用户信号品质。当最初与第一BS通信的MS进入第一和第二BS覆盖区域的交叠部分,并且第二BS向MSC报告已收到足够强度的信号时MSC就需要用到上述的软切换方法。在结合信号分集合并的软切换过程中,MS与MSC的通信不会中断。MSC典型地采用后检测/解码、数字的编码语言帧选择性合并。Assisted mobile soft handover combined with signal diversity combining includes the following methods: on the uplink and downlink, via the first and second BS, the transmission segment between the MS and the MSC transmits user communication signals simultaneously, and the signal is performed between the MS and the MSC Diversity reception to improve user signal quality. When the MS initially communicating with the first BS enters the overlapping part of the coverage area of the first and second BS, and the second BS reports to the MSC that it has received a signal of sufficient strength, the MSC needs to use the above-mentioned soft handover method. During the soft handoff combined with signal diversity, the communication between MS and MSC will not be interrupted. MSC typically employs post-detection/decoding, digitally encoded speech frame selective incorporation.

为了在软切换起动过程中实现MS的辅助报告功能,所有的BS都要发送一个下行链路CDMA参考信号,称为导频信号。当MS在CDMA蜂窝通信系统的服务区域里漫游时,在与第一BS通信的同时,要周期性地解调来自不同的相邻BS的导频信号,从中导出相应导频信号品质指示。再者,测量到的导频信号Eb/Nb值,可以作为信号强度/品质的指示,用这个指示来确定一个可供软切换选择的基站列表,并以信令信息的方式发送给MSC。需要注意的是,第一BS也在连续地进行CDMA下行链路信号品质检测,并且这些检测的结果,发送给MSC一个软切换要求的指示。In order to realize the auxiliary reporting function of MS during the soft handover start process, all BSs must send a downlink CDMA reference signal, which is called a pilot signal. When the MS is roaming in the service area of the CDMA cellular communication system, while communicating with the first BS, it needs to periodically demodulate pilot signals from different neighboring BSs, and derive corresponding pilot signal quality indications therefrom. Furthermore, the measured pilot signal Eb/ Nb value can be used as an indicator of signal strength/quality, and this indicator is used to determine a list of base stations that can be selected for soft handover, and sent to the MSC in the form of signaling information. It should be noted that the first BS is also continuously detecting the quality of the CDMA downlink signal, and the results of these detections are sent to the MSC to indicate that a soft handover is required.

通常,如果MS报告说,不但第一BS的导频信号,而且第二个BS导频信号品质也足够好地满足MS预先确定的门限,并且MSC和第二BS也能获得进行软切换所需的资源,于是,MSC就开始进行结合信号分集合并的软切换。接着,通过第一BS,在MSC以信令方式的指挥下,MS开始软切换,并在下行链路上开始信号分集合并。Usually, if the MS reports that not only the pilot signal of the first BS, but also the pilot signal quality of the second BS is good enough to meet the MS pre-determined threshold, and the MSC and the second BS can also obtain the required soft handover. resources, so the MSC starts to perform soft handover combined with signal diversity. Then, through the first BS, under the command of the MSC in the form of signaling, the MS starts soft handover and starts signal diversity combining on the downlink.

此外,MSC经由第二BS开始用户信号的附加传递,并在上行链路方向上开始用户信号的分集合并。参与此事的这两个BS都自动实行前述的闭环功率控制方法。MS将它的CDMS发射功率设置为两BS所需功率水平的较小值,以减小对其它CDMA通信链路产生的额外干扰。Furthermore, the MSC starts additional delivery of user signals via the second BS and starts diversity combining of user signals in the uplink direction. Both BSs involved in this matter automatically implement the aforementioned closed-loop power control method. The MS sets its CDMS transmit power to the smaller value of the power levels required by the two BSs to reduce additional interference to other CDMA communication links.

最后,当MS确切地处于第二BS的服务区域内,而且接收到的从第一BS来的导频信号已降至预先确定的MS所需门限值以下时,MS将此情况报告给MSC,MSC接着决定中止软切换及信号的分集合并,然后仅利用第二BS来保持CDMA通信。Finally, when the MS is definitely within the service area of the second BS and the received pilot signal from the first BS has fallen below a predetermined threshold required by the MS, the MS reports this to the MSC , the MSC then decides to suspend the soft handoff and diversity combining of the signals, and then use only the second BS to maintain CDMA communication.

当MS在CDMA蜂窝通信系统的服务区域内移动时,根据所测量到的CDM信号品质的指示,这种结合信号分集合并的软切换将不断重复地进行。When the MS moves within the service area of the CDMA cellular communication system, according to the indication of the measured CDM signal quality, this kind of soft handover combined with signal diversity will be carried out repeatedly.

一些现代的TDMA蜂窝通信系统也利用MS的帮助,以相应的MS下行链路信号品质测量作为指标来要求一次从第一BS到第二BS的切换,与上述方式有很多相似之处。然而,这些系统常常使用一种所谓硬切换方式,MS根据MSC的指令,切断与第一BS的联系,调谐到所指示的第二BS的TDMA无线信道上来,然后恢复上行链路和下行链路的通信。MS不会同时与一个以上的BS通信,这样,在MS和MSC中都不会发生上述软切换方式中出现的信号分集合并,这种常规硬切换方法也可以类似的方式应用于CDMA,但由于下述CDMA系统容量方面的原因,尽可能不这样做。Some modern TDMA cellular communication systems also use the help of MS to request a handover from the first BS to the second BS with the corresponding MS downlink signal quality measurement as an indicator, which has many similarities with the above-mentioned methods. However, these systems often use a so-called hard handover method. According to the instructions of the MSC, the MS cuts off the connection with the first BS, tunes to the TDMA radio channel of the second BS indicated, and then resumes the uplink and downlink. Communication. The MS will not communicate with more than one BS at the same time. In this way, the signal diversity combination in the above-mentioned soft handover method will not occur in the MS and the MSC. This conventional hard handover method can also be applied to CDMA in a similar manner, but due to For reasons of the capacity of the CDMA system described below, this should not be done as much as possible.

与软切换和硬切换有关的概念中,以前提及的预先确定的门限值也被称作切换容限,它用于以下行链路信号品质的测量以确定进行切换的候选BS。为避免当MS进入两个相邻BS无线信号覆盖区域的模糊边界时,引起频繁的切换(称为切换乒乓效应)必须同时运用这些切换容限和时间平均处理方法。这种频繁的切换会引起MSC处理容量的过载。为控制结合信号分集合并的CDMA软切换,切换容限可以选择小到1-3dBd左右,与此相对比,为避免有害的切换乒乓效应,常规硬切换容限常常需要6-10dB。In the concepts related to soft handover and hard handover, the previously mentioned predetermined threshold value is also called handover tolerance, which is used to determine the candidate BS for handover by measuring the quality of the downlink signal. In order to avoid frequent handovers (called the handover ping-pong effect) when the MS enters the fuzzy boundary of the wireless signal coverage area of two adjacent BSs, these handover tolerance and time-average processing methods must be used at the same time. Such frequent switching will cause an overload of MSC processing capacity. To control CDMA soft handover combined with signal diversity combining, the handover tolerance can be selected as small as about 1-3dBd, compared to 6-10dB for conventional hard handover to avoid harmful handover ping-pong effects.

考虑到前述的干扰限制了CDMA的运行,选取小的切换容限是CDMA有效运行的必要条件。采用常规CDMA硬切换所必需的较大的硬切换容限会明显地降低CDMA系统容量。只有在特殊情况下,CDMA蜂窝通信系统才会采用硬切换,而不能将其作为系统操作的一般模式。本发明的半硬切换可以弥补常规硬切换方式的不足。Considering that the aforementioned interference limits the operation of CDMA, choosing a small switching tolerance is a necessary condition for effective operation of CDMA. Adopting the larger hard handover tolerance necessary for conventional CDMA hard handover will obviously reduce the capacity of the CDMA system. Only in special cases, the CDMA cellular communication system will adopt hard switching, but it cannot be used as a general mode of system operation. The semi-hard handover of the present invention can make up for the deficiency of the conventional hard handover.

另一种有问题的切换是MSC之间的切换,也就是连接在相邻MSC上的BS之间的切换。以图1示出现有技术的蜂窝系统为例,来说明这种情形。MS20可以在MSC1控制的软切换区域SA1内进行软切换,也可以在MSC2的区域SA2内进行软切换。但当它进入这两个区域的交界处时,就不能进行软切换了。例如,MS20处于BS12和BS14的交界区时,就不能进行软切换了。假定MS20与BS12相连接,而且它向BS14移动,在现有技术的系统中,若要将MS20从软切换区SA1切换到另一软切换区SA2,那末从BS12到BS14以及从MSC1到MSC2必须进行常规的MSC之间的CDMA硬切换。由于硬切换所必需的切换容限,这种常规硬切换是不可靠的,而且对CDMA容量有非常不利的影响。Another problematic handover is inter-MSC handover, that is, handover between BSs connected to adjacent MSCs. This situation will be described by taking the prior art cellular system shown in FIG. 1 as an example. MS20 can perform soft handover in the soft handover area SA1 controlled by MSC1, and can also perform soft handover in area SA2 of MSC2. But when it enters the junction of these two regions, soft handoff cannot be performed. For example, when MS20 is in the boundary area between BS12 and BS14, soft handover cannot be performed. Suppose MS20 is connected with BS12, and it moves toward BS14, in the system of prior art, if MS20 will be handed over to another soft handover area SA2 from soft handover area SA1, so from BS12 to BS14 and from MSC1 to MSC2 must Perform conventional CDMA hard handover between MSCs. Such conventional hard handoffs are unreliable and have a very negative impact on CDMA capacity due to the handover margins necessary for hard handoffs.

本发明的目的是避免常规CDMA的MSC间硬切换带来的不利影响(如降低系统容量)。The purpose of the present invention is to avoid the adverse effect (such as reducing the system capacity) brought by the hard handover between MSCs of the conventional CDMA.

本发明的一个部分是一个蜂窝通信系统,它包括:One part of the present invention is a cellular communication system comprising:

多个移动站;multiple mobile stations;

一个第一移动交换机;a first mobile exchange;

一个第二移动交换机;a second mobile exchange;

多个基站,其中第一组基站只与所述第一移动交换机相连接第二组基站只与所述第二移动交换机相连接,在所述多个基站中,至少有一个基站是一个边界基站,同时与所述第一移动交换机和第二移动交换机相连接。A plurality of base stations, wherein a first group of base stations is only connected to the first mobile exchange and a second group of base stations is only connected to the second mobile exchange, and among the plurality of base stations, at least one base station is a border base station , connected to the first mobility switch and the second mobility switch at the same time.

本发明的另一部分是一种半硬切换方式,用于将通信控制功能从所述第一移动交换机切换到所述第二移动交换机,而不影响所述移动站和所述至少一个边界基站之间的无线通信。Another part of the present invention is a semi-hard handover method for switching communication control functions from said first mobile exchange to said second mobile exchange without affecting the relationship between said mobile station and said at least one border base station wireless communication between.

按照本发明,使用了一种新CDMA切换处理方式,下文中称之为半硬切换。半硬切换发生在上述的同一个基站上(下文称之为边界基站),该基站位于两个不同的移动交换机(下文称之为相邻移动交换机)所控制的无线覆盖区域的交界处。该边界基站被连接到这两个相邻移动交换机,从这两个相邻移动交换机也都可以接入到该边界基站。According to the present invention, a new CDMA handover process is used, hereinafter referred to as semi-hard handover. The semi-hard handover occurs on the same base station (hereinafter referred to as border base station), which is located at the junction of wireless coverage areas controlled by two different mobile exchanges (hereinafter referred to as adjacent mobile exchanges). The border base station is connected to the two adjacent mobile exchanges from which the border base station is also accessible.

所发明的半硬切换是一种基于网络的、从第一到第二相邻移动交换机的通信控制功能的切换,而不中断边界基站和移动站之间正在进行的CDMA无线通信。半硬切换要求基站上有转换设施,用来将用户无线通信信号耦合到任何与之相连的相邻移动交换机上,在实施半硬切换中这是需要的。The invented semi-hard handover is a network-based handover of the communication control function from the first to the second adjacent mobile exchange without interrupting the ongoing CDMA wireless communication between the border base station and the mobile station. Half-hard handover requires switching facilities on the base station to couple the user's wireless communication signal to any adjacent mobile exchange connected to it, which is required in the implementation of half-hard handover.

借助于相邻移动交换机的多路连接和边界基站上的转换设备,在相邻移动交换机之间提供了一个交叠软切换服务区,这在现有技术的蜂窝通信系统中是没有的。半硬切换发生在交叠软切换服务区内(是由边界基站引发的),这样避免了不利的常规COMA交换机间的硬切换。By means of the multiple connections of adjacent mobile exchanges and switching equipment at the border base stations, an overlapping soft handoff service area is provided between adjacent mobile exchanges, which is not available in prior art cellular communication systems. The semi-hard handover occurs within the overlapping soft handover service area (initiated by the border base stations), thus avoiding the disadvantageous hard handover between conventional COMA switches.

从下面结合附图所作的详细描述中,本发明的特征和优点会更加明显。The features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

图1示出现有技术的CDMA蜂窝通信系统的简图;Fig. 1 shows the simplified diagram of the CDMA cellular communication system of prior art;

图2示出根据本发明的一个CDMA蜂窝通信系统实例的简图;Fig. 2 shows the simplified diagram according to a CDMA cellular communication system example of the present invention;

图3是用于CDMA蜂窝通信系统中的移动交换中心的优选实施例的框图;Figure 3 is a block diagram of a preferred embodiment for a mobile switching center in a CDMA cellular communication system;

图4是用于COMA蜂窝通信系统中的基站的优选实施例的框图。Figure 4 is a block diagram of a preferred embodiment of a base station for use in a COMA cellular communication system.

图2示出本发明的涉及的一个CDMA蜂窝通信系统的实例。图中描述的系统提高了现有技术的CDMA软切换及宏分集信号合并技术,这在“将码分多址(CDMA)应用于数字蜂窝及个人通信网的系统设计”一文中有详细说明。论文作者是Allen Salmasi和Kleins Gilhousen,发表于第41届IEEE移动技术会议,会议于1991年5月19-22日在密苏里州圣路易斯召开。Fig. 2 shows an example of a CDMA cellular communication system to which the present invention relates. The system depicted in the figure enhances the prior art CDMA soft handover and macrodiversity signal combining techniques described in detail in "System Design Applying Code Division Multiple Access (CDMA) to Digital Cellular and Personal Communication Networks". Paper by Allen Salmasi and Kleins Gilhousen presented at the 41st IEEE Mobile Technology Conference, May 19-22, 1991 in St. Louis, Missouri.

BS12是一个边界BS,通过链路32,34连接到相邻MSC1和MSC2,BS12同时与MSC1,MSC2的连接有效地扩大了MSC1,MSC2各自的软切换区域SA1和SA2,从而产生了一个交叠软切换区域OA。其它不处于覆盖交界区的BS10,14,只需与单个MSC(MSC1或MSC2)相连接。半硬切换发生在交叠覆盖区OA内。BS12 is a border BS connected to adjacent MSC1 and MSC2 via links 32, 34. The simultaneous connection of BS12 to MSC1 and MSC2 effectively expands the respective soft handover areas SA1 and SA2 of MSC1 and MSC2, thereby creating an overlapping Soft handover area OA. Other BSs 10, 14 that are not in the coverage boundary area only need to be connected with a single MSC (MSC1 or MSC2). Semi-hard handover takes place within the overlapping coverage area OA.

下面描述半硬切换和现有技术的软切换的使用。假定MS20从软切换区SA1向SA2移动,依次穿过BS10,12,14的无线电覆盖区域。The use of semi-hard handover and prior art soft handover is described below. Assume that MS 20 moves from soft handover area SA1 to SA2, passing through the radio coverage areas of BSs 10, 12, 14 in turn.

假定MS20最初与BS10相连接,并通过MSC1与其它系统的用户(假定是PSTN中的用户)连接,当MS20继续移动,进入边界BS12的无线电覆盖区域。由于BS12通过链路32连接在MSC1上,按照现有技术的软切换开始进行。MSC1用作信号分集合并点,并且继续控制着这种连接。Assume that MS20 is initially connected to BS10, and connects with users of other systems (assumed to be users in the PSTN) through MSC1. When MS20 continues to move, it enters the radio coverage area of border BS12. Since BS12 is connected to MSC1 via link 32, a soft handover according to the prior art is initiated. MSC1 acts as a signal diversity combining point and continues to control the connection.

当MS20远离BS10并靠近BS12,按照现有技术的软切换被终止,MS20仅与BS12通信(经由MSC1)。When MS20 moves away from BS10 and approaches BS12, the soft handover according to the prior art is terminated and MS20 only communicates with BS12 (via MSC1).

MS20持续地测量来自BS10,12,14的导频信号强度,并以相邻小区测量报告的形式送回至MSC1,若这些导频信号的强度显示MS20已确切地处于BS12的覆盖区内并继续从BS10向BS14方向移动,本发明的半硬切换将由MSC1启动,其过程如下:MS20 continuously measures the strength of pilot signals from BS10, 12, 14 and sends back to MSC1 in the form of neighbor cell measurement reports, if the strength of these pilot signals shows that MS20 is definitely within the coverage area of BS12 and continues Move toward BS14 direction from BS10, semi-hard handover of the present invention will be started by MSC1, and its process is as follows:

-从MS20所作的导频信号品质测量报告中,MSC1了解到MS20已确实处于BS12的覆盖区域内,并继续远离BS10而趋近BS14。此外,从蜂窝网络设备配置数据中,MSC1了解到BS12也可被MSC2接入(通过链路34)。因此,按照预先确定的门限参数,可由MSC1决定MSC1向MSC2的半硬切换。为了这个目的,将在数字链路40上保留一个通向MSC2的线路。MSC1也已经在下行链路方向建立了一个分路连接,将链路40上的新线路与来自PSTN的支路42连接起来。- From the pilot signal quality measurement report made by MS20, MSC1 knows that MS20 is indeed in the coverage area of BS12, and continues to move away from BS10 and approach BS14. Furthermore, from the cellular network device configuration data, MSCl knows that BS 12 is also accessible (via link 34) by MSC2. Therefore, according to the predetermined threshold parameter, MSC1 can decide the semi-hard handover from MSC1 to MSC2. A line to MSC2 will be reserved on digital link 40 for this purpose. MSC1 has also established a branch connection in the downlink direction, connecting the new line on link 40 with branch 42 from the PSTN.

-MSC1向MSC2发送适当的信令信息,要求进行向MSC2的半硬切换,同时指明传输链路40上新分配的线路。MSC2接着分配、启动为处理和控制正在进行的通信的所需资源。这些资源包括(但不限于):执行上行链路用户信息帧(用于将来可能的SA2内的软切换)分集合并的设施;用于语音通信的代码转换设备;移动站和基站信令链路终端和适当的控制处理部分。- MSC1 sends appropriate signaling information to MSC2, requesting a half-hard handover to MSC2, and at the same time indicating the newly allocated line on the transmission link 40. MSC2 then allocates and activates the required resources for processing and controlling ongoing communications. These resources include (but are not limited to): facilities to perform diversity combining of uplink user information frames (for possible future soft handover within SA2); transcoding equipment for voice communications; mobile station and base station signaling links terminal and appropriate control processing sections.

-MSC2在与BS12相连接的数字链路32上分配一个线路,并向BS12发送适当的信令信息,要求进行BS12中的半硬切换,同时指明传输链路34上新分配的线路。- MSC2 allocates a line on the digital link 32 connected to BS12 and sends appropriate signaling information to BS12 requesting a half-hard handover in BS12 and indicating the newly allocated line on transmission link 34.

-BS12利用它的交换器250(见图4),将它与MS20之间正在传送的无线通信信号转换到链路34中新分配的线路上。然后BS12将发回适当信号给MSC2,通告该转换成功完成。- BS12 uses its switch 250 (see FIG. 4) to switch the wireless communication signal being transmitted between it and MS20 to the newly allocated line in link 34. BS12 will then send an appropriate signal back to MSC2, announcing the successful completion of the switch.

-MSC2向MSC1发回适当信号,通告半硬切换成功完成。- MSC2 sends an appropriate signal back to MSC1, announcing the successful completion of the semi-hard handover.

-在MSC2内部,将它与MS20之间的信令链路和新分配的控制处理部分连接起来。此时MSC2立即向MS20发送一个信令链路复位指示至MS-MSC链路的第二层,以恢复信令连接的一致性。MS20对它的信号链路上下文,连同MSC2,实行初始化,以作为对这个复位操作指示的响应。但这个复位操作不影响物理无线链路层(第一层)。这样,通常的CDMA闭环功率控制仍可在MS20和作为支持的BS12之间进行,而不会因半硬切换而有任何中断。此外,涉及呼叫处理(第三层)的信令也不受影响。- Inside MSC2, connect it with the signaling link between MS20 and the newly assigned control processing part. At this time, MSC2 immediately sends a signaling link reset instruction to MS20 to the second layer of the MS-MSC link, so as to restore the consistency of the signaling connection. MS 20 initializes its Signal Link Context, together with MSC 2, in response to this reset operation indication. But this reset operation does not affect the physical radio link layer (layer 1). In this way, the usual CDMA closed-loop power control can still be performed between the MS 20 and the supporting BS 12 without any interruption due to the semi-hard handover. Furthermore, signaling related to call processing (Layer 3) is not affected.

-MSC1收到MSC2传送的半硬切换成功完成的通告后,将链路32的上行链路方向转换成新链路40的上行链路方向,并将后者与链路42上的线路相连接。这一操作完成后,MS20的用户信息与PSTN的双向通信全部恢复。MSC1将释放涉及该用户通信的资源,包括(但不限于):完成上行链路用户信息帧分集合并的设施;用于语音通信的语音代码转换设备;MS和BS信令链路终端和相应的控制处理部分。MSC1还释放数字链路32上连向BS12的线路。这样MSC1不再涉及呼叫控制,但仍作为数字链路40和42的转接点,这样完成了本发明的半硬切换过程。其结果是,无线链路控制功能从MSC1切换到了MSC2,而没有中断BS12和MS20间的无线链路,特别是没有中断对MS20的闭环功率控制。现有技术中由MSC2控制的软切换操作,可以在软切换区域SA2里进行,例如,当MS20继续向BS14移动时,就可以开始一个从BS12到BS14的软切换。- MSC1 converts the uplink direction of the link 32 to the uplink direction of the new link 40 after receiving the notification of the successful completion of the half-hard handover transmitted by the MSC2, and connects the latter to the line on the link 42 . After this operation is completed, the two-way communication between the user information of MS20 and the PSTN is fully restored. MSC1 will release the resources related to the communication of this user, including (but not limited to): facilities for completing diversity combining of uplink user information frames; voice transcoding equipment for voice communication; MS and BS signaling link terminals and corresponding Control processing section. MSC1 also releases the line on digital link 32 to BS12. In this way, MSC1 is no longer involved in call control, but still serves as the transfer point of digital links 40 and 42, thus completing the semi-hard handover process of the present invention. As a result, the radio link control function is switched from MSC1 to MSC2 without interrupting the radio link between BS12 and MS20, especially without interrupting the closed-loop power control of MS20. The soft handover operation controlled by MSC2 in the prior art can be performed in the soft handover area SA2. For example, when MS20 continues to move to BS14, a soft handover from BS12 to BS14 can be started.

这样,避免了从MSC1到MSC2的常规CDMA硬切换,而相应提高了系统的可靠性和容量。In this way, the conventional CDMA hard handover from MSC1 to MSC2 is avoided, and the reliability and capacity of the system are correspondingly improved.

图3示出本发明涉及的用于一个CDMA蜂窝通信系统的一个MSC的实施范例。Fig. 3 shows an embodiment example of an MSC used in a CDMA cellular communication system to which the present invention relates.

数字链路120,122,124,126将移动交换机MSC分别地与公共交换电话网PSTN、其它移动交换机MSC、基站BS相连接。Digital links 120, 122, 124, 126 connect the mobile switch MSC with the public switched telephone network PSTN, other mobile switches MSC, base stations BS, respectively.

这些数字链路传送用户信息如语音,此外还有信令信息。本发明的优选实施例假定信令信息和用户信息一起被复用于同一个物理传输设备中。T1传输设备和第7号信令系统一起可以作为这种数字链路设备的实施范例。These digital links carry user information such as voice, in addition to signaling information. The preferred embodiment of the present invention assumes that signaling information and user information are multiplexed together in the same physical transmission device. T1 transmission equipment together with Signaling System No. 7 can be used as an example of the implementation of such digital link equipment.

利用数字交换器112,用户信息流可以在前述实体内进行交换。相应的信令信息由一个分组交换器114来进行传输,接收或中继。分组交换器114也连接在一个MSC控制处理器110上,该控制处理器110可分别作为信令信息的信源和信宿。MSC控制处理器110对发给它的信令信息进行解释和作出反应,也适时地向其它实体发送请求信令信息。MSC控制处理器110同时根据呼叫状态,去控制数字交换器112中的连接安排。此外,MSC控制处理器110在呼叫建立或拆除过程中,从相应的资源存贮区里分配设备100中的代码转换器和合并器,或者释放它们。(图中仅示出一个这种包含代码转换器和合并器的设备100)。Using the digital switch 112, user traffic can be switched within the aforementioned entities. The corresponding signaling information is transmitted, received or relayed by a packet switch 114 . The packet switch 114 is also connected to an MSC control processor 110, and the control processor 110 can serve as a source and a sink of signaling information respectively. The MSC control processor 110 interprets and responds to the signaling information sent to it, and also sends request signaling information to other entities in a timely manner. The MSC control processor 110 also controls the connection arrangement in the digital switch 112 according to the call state. In addition, the MSC control processor 110 allocates the transcoders and combiners in the device 100 from corresponding resource storage areas, or releases them during call setup or teardown. (Only one such device 100 including a transcoder and combiner is shown in the figure).

包含代码转换器和合并器的设备100用于以下两者的转换:即用于PSTN中的典型的μ律语音编码;用于无线链路的诸如CELP的低速率数字化语音编码。除代码转换功能外,包含代码转换器和合并器的设备100还完成上行链路方向的信号分集合并和下行链路方面的信号复制。此外,在结合信号分集合并的软切换过程中,包含代码转换器和合并器的设备100将以下两种信息流同步起来:一种信息流是来自或发向参与通信的基站,它通过数字链路124,126传输,通过数字交换器112交换,通过线路130,132传给包含代码转换器和合并器的设备100;另一种信息流是来自或发向PSTN,它通过数字链路120,数字交换器112和线路134传输过来。(图2中只画出两分支BS分集)。The device 100 comprising a transcoder and combiner is used for the conversion of both: typical μ-law speech coding used in PSTN; low rate digitized speech coding such as CELP for wireless links. In addition to the transcoding function, the device 100 comprising transcoders and combiners also performs diversity combining of signals in the uplink direction and signal duplication in the downlink direction. In addition, in the soft handover process combined with signal diversity combining, the device 100 including the transcoder and the combiner synchronizes the following two information flows: one information flow is from or to the participating Road 124, 126 transmission, exchanged by digital switch 112, passed to equipment 100 comprising transcoder and combiner through lines 130, 132; another kind of information flow is from or sent to PSTN, it passes digital link 120, Digital switch 112 and line 134 transmit. (Only the two-branch BS diversity is shown in Figure 2).

在本发明的优选实施例中,用户通信信号,包括数字化语音信号或数据,和与这一连接有关的信令信息复用在一起,纳入数字化的帧格式,这一格式适于在BS和MSC间的地面传输链路124,126上传输。相应地,这些帧被称为代码转换器/合并器帧,在用户信息之外,代码转换器/合并器帧还包括BS提供的与信号品质相关的信息,这些信息用于MSC内进行的上行链路方向上的信号分集合并。此外,代码转换器/合并器帧还包括BS和MSC提供的数字信号。这些信号,在结合信号分集合并的软切换期间,与BS和MSC之间的同步链路124,126的同步化有关。In a preferred embodiment of the present invention, user communication signals, including digitized voice signals or data, and signaling information related to this connection are multiplexed together into a digitized frame format, which is suitable for communication between the BS and the MSC. Transmission on the ground transmission link 124,126 between. Correspondingly, these frames are called transcoder/combiner frames. In addition to user information, transcoder/combiner frames also include information related to signal quality provided by the BS, which is used for uplink in the MSC. Diversity combining of signals in link direction. In addition, the transcoder/combiner frame also includes digital signals provided by the BS and MSC. These signals are related to the synchronization of the synchronization links 124, 126 between the BS and the MSC during soft handover in conjunction with signal diversity combining.

在上行和下行链路方向上,分别通过线路130,132,134传入或传出的代码转换器/合并器帧都在数字存贮器104里缓存,数字处理器102周期地读/写数字存贮器中的代码转换器/合并器帧。在上行链路方向,附属于代码转换器/合并器帧的信号品质指示信息经线路130、132进入存贮器104,通过检查这些指示信息,根据这些指示,处理器102执行分集选择。在下行链路方向,经线路134进入存贮器104的语音抽样,由处理器102进行代码转换和组装,形成代码转换器/合并器帧。Transcoder/combiner frames incoming or outgoing via lines 130, 132, 134, respectively, in the uplink and downlink directions are buffered in digital memory 104, and digital processor 102 periodically reads/writes the digital Transcoder/merger frames in memory. In the uplink direction, the signal quality indicators attached to the transcoder/combiner frames are entered into the memory 104 via lines 130, 132. By examining these indicators, the processor 102 performs diversity selection based on these indicators. In the downlink direction, speech samples entering memory 104 via line 134 are transcoded and assembled by processor 102 to form transcoder/combiner frames.

通过数字处理器102,包含代码转换器和合并器的设备100,从代码转换器/合并器帧里提取或插入用户信令信息,通过线路140,向MSC控制处理器110提供或接收这些用户信令信息。通过这种方法,MSC控制处理器110接收到MS信令信息,如导频信号品质测量报告。这样MSC控制处理器110就获得了开始或结束软切换和半硬切换所需要的信息。此外,以这种方式,MSC控制处理器110通过线路140,130,132和链路124,126向MS发送适当的切换命令,如有必要,可以通过数字分组交换器114和链路122向其它MSC发送这些命令。The device 100, including transcoders and combiners, extracts or inserts user signaling information from transcoder/combiner frames via digital processor 102, and provides or receives these user signaling information to and from MSC control processor 110 via line 140. order information. In this way, the MSC control processor 110 receives MS signaling information, such as a pilot signal quality measurement report. In this way, the MSC control processor 110 obtains the information needed to start or end soft handover and semi-hard handover. Furthermore, in this manner, the MSC control processor 110 sends appropriate handoff commands to the MS via lines 140, 130, 132 and links 124, 126 and, if necessary, to other MSCs via digital packet switch 114 and links 122. MSC sends these commands.

图4示出涉及本发明的CDMA蜂窝通信系统的基站的一个实施范例。Fig. 4 shows an embodiment example of a base station of a CDMA cellular communication system related to the present invention.

模块200表示一个基站中支持单个CDMA通信所需的装置,称为CDMA信道设备。在图4中示出三个类似的信道单元200A,200B,200C。Block 200 represents the equipment required in a base station to support a single CDMA communication, referred to as CDMA channel equipment. In FIG. 4 three similar channel units 200A, 200B, 200C are shown.

根据本发明,基站分别通过数字链路232A和232B连接到移动交换机,例如MSC1和MSC2。在数字链路232A和232B与信道单元200之间有一个数字交换器250,它将来自或发向信道单元200A,200B,200C的用户信息流在数字链路232A和232B之间进行交换。通过数字交换器250的这种连接可以是动态连接,即它是一经要求,即时交换的线路,或者这种交换可以是一种快速分组交换的形式。本发明的优选实施例中,交换器250属于即时交换的线路类型。图4示出的基站配置适用于图2中的基站12,基站10和14可以是类似配置,但由于只需一个MSC链路,数字交换器250可以省去。According to the invention, the base stations are connected to mobile exchanges, eg MSC1 and MSC2, via digital links 232A and 232B, respectively. Between the digital links 232A and 232B and the channel unit 200 is a digital switch 250 which switches user traffic from or to the channel units 200A, 200B, 200C between the digital links 232A and 232B. The connection through digital switch 250 may be a dynamic connection, ie it is a line switched on demand, or the switching may be a form of rapid packet switching. In the preferred embodiment of the present invention, the switch 250 is of the line type of instant switching. The base station configuration shown in FIG. 4 is applicable to the base station 12 in FIG. 2, and the base stations 10 and 14 can be configured similarly, but since only one MSC link is required, the digital switch 250 can be omitted.

在上行链路方向,接收的CDMA用户通信信号来自数字CDMA无线链路230,它由CDMA解调器202解调,由解交织/解码器206进行解交织和解码,为用于地面传输,转换成代码转换器/合并器帧并缓存于数字存贮器210,最终通过数字交换器250转换到所选数字链路232A和232B中的一个,向MSC1或MSC2传输。In the uplink direction, the received CDMA user communication signal comes from digital CDMA radio link 230, which is demodulated by CDMA demodulator 202, deinterleaved and decoded by deinterleaver/decoder 206, for terrestrial transmission, converted into a transcoder/combiner frame and buffered in digital memory 210, and finally converted to one of selected digital links 232A and 232B by digital switch 250 for transmission to MSC1 or MSC2.

在下行链路方向,通过数字链路232A或232B,接收到来自MSC1或MSC2的代码转换器/合并器帧,由数字交换器250将它连接到信道单元200A,200B,200C中适当的一个,在数字存贮器210中缓存并转换成适合于基站的表示形式,并由编码/交织器208进行信道编码,由CDMA调制器204进行CDMA调制,最终从数字无线链路230上发送出去。In the downlink direction, via digital link 232A or 232B, a transcoder/combiner frame is received from MSC1 or MSC2, which is connected by digital switch 250 to an appropriate one of channel units 200A, 200B, 200C, Buffered in the digital memory 210 and converted into a representation form suitable for the base station, channel coded by the encoder/interleaver 208 , CDMA modulated by the CDMA modulator 204 , and finally sent out from the digital wireless link 230 .

本发明的优选实施例中,BS有一个独立于网络的时钟源220,能提供有效的CDMA运行所需的高精度参考信号,并用于CDMA信道设备200中。这种时钟源可以从比如GPS卫星信号中提取,可以提供给全球范围内的每个BS,从而建立相互同步的BS网络。In the preferred embodiment of the present invention, the BS has a clock source 220 independent of the network, which can provide a high-precision reference signal required for effective CDMA operation, and is used in the CDMA channel device 200. This clock source can be extracted from, for example, GPS satellite signals, and can be provided to each BS around the world, thereby establishing a mutually synchronized BS network.

BS还包括一个BS控制处理器222,BS控制处于器222通过连接到MSC1和MSC2的数字链路232A和232B,分别地接收和发送信令信息。BS控制处理器222还执行基站资源管理,诸如用于用户连接(呼叫)的CDMA信道设备的分配和释放。BS控制处理器222将对与呼叫建立有关的CDMA信道分配请求作出响应,同样也对来自MSC的与软切换、半硬切换有关的CDMA信道分配请求作出响应。The BS also includes a BS control processor 222 which receives and transmits signaling information via digital links 232A and 232B connected to MSC1 and MSC2, respectively. The BS control processor 222 also performs base station resource management, such as allocation and release of CDMA channel equipment for user connections (calls). BS control processor 222 will respond to CDMA channel allocation requests related to call setup, and also respond to CDMA channel allocation requests from MSC related to soft handover and semi-hard handover.

在上行链路和下行链路方向上,数字处理器212和缓存器210一起,分别从代码转换器/合成器帧中拆卸或装入以BS内部形式表示的CDMA用户通信信号。在本发明的优选实施例中,前述代码转换器/合成器帧中还包括由解交织/信道解码器206提供的信息,该信息提供给数字处理器212,作为从上行CDMA无线链路230接收过来的CDMA无线帧信号品质的指示,并且在上行链路方向上,用于MSC内的信号分集合并。In the uplink and downlink directions, the digital processor 212, together with the buffer 210, de-loads and loads, respectively, the CDMA user communication signals represented in BS-internal form from the transcoder/synthesizer frames. In a preferred embodiment of the present invention, the aforementioned transcoder/synthesizer frame also includes information provided by the de-interleaver/channel decoder 206, which is provided to the digital processor 212 as received from the uplink CDMA radio link 230 An indication of the signal quality of incoming CDMA radio frames, and in the uplink direction, used for signal diversity combining within the MSC.

如上所述,本发明涉及一种交换机之间的切换,称为交换机间半硬切换。在这里假定这些与此切换有关的MCS,是通过数字链路永久地或临时地连接在一起,并在其间传输用户通信信号和MSC之间的切换信令信息。As mentioned above, the present invention relates to a handover between switches, called inter-switch semi-hard handover. It is assumed here that these MCSs related to the handover are permanently or temporarily connected together through digital links, and transmit user communication signals and handover signaling information between MSCs among them.

同时必须理解的是,本发明的方法可以很容易地应用于TDMA蜂窝通信系统。在一个TDMA蜂窝通信系统中,无线链路应该是TDMA无线链路,其中时隙用来向系统用户提供通信信道。在结合分集合并的软切换中,两个(或更多)时隙用来提供并行的无线信道,以供涉及切换的BS和MS使用。所有其它提及的本发明的特征,在TDMA蜂窝系统中保持不变。At the same time it must be understood that the method of the present invention can be readily applied to TDMA cellular communication systems. In a TDMA cellular communication system, the radio link should be a TDMA radio link in which time slots are used to provide communication channels to system users. In soft handover combined with diversity combining, two (or more) time slots are used to provide parallel radio channels for the BS and MS involved in the handover. All other mentioned features of the invention remain unchanged in TDMA cellular systems.

前面对优选实施例的描述是用来帮助任何本领域的技术人员制作或使用本发明。对于本领域的技术人员来说,对这些实施范例所作的各种修改将是非常明显的,并且无需用到创造才能,就可以将此处定义的一般原理应用到其它实施范例中。因此,本发明并不试图限制于举出的实施范例,而应给予与此处作为新的特征公布的原理相一致的最大范围。The foregoing description of the preferred embodiment is provided to assist any person skilled in the art in making or using the invention. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other examples without undue ingenuity. Thus, the invention is not intended to be limited to the examples of implementation presented, but is to be accorded the widest scope consistent with the principles disclosed herein as novel features.

Claims (6)

1.一种蜂窝通信系统,它包括:1. A cellular communication system comprising: 多个移动站(MS20);multiple mobile stations (MS20); 一个第一移动交换机(MSC1);a first mobility exchange (MSC1); 一个第二移动交换机(MSC2);a second mobility switch (MSC2); 多个基站,一个第一组(BS10)所述多个基站,它只与所述第一移动交换机(MSC1)相连接,一个第二组(BS14)所述多个基站,它只与所述第二移动交换机(BSC2)相连接,至少有一个基站是一个边界基站(BS12),同时与所述第一移动交换机和第二移动交换机相连接;A plurality of base stations, a first group (BS10) of said plurality of base stations, which are only connected to said first mobile exchange (MSC1), a second group (BS14) of said plurality of base stations, which are only connected to said The second mobile exchange (BSC2) is connected, and at least one base station is a border base station (BS12), and is connected with the first mobile exchange and the second mobile exchange at the same time; 在所述第一移动交换机中,向所述第二移动交换机请求一次半硬切换的设备;In the first mobility switch, a device that requests a semi-hard handover from the second mobility switch; 在所述第二移动交换机中,用于分配控制和分集合并资源的设备,这些资源被所述第二移动交换机用于处理和控制用户信息;In said second mobility switch, means for allocating control and diversity combining resources used by said second mobility switch for processing and controlling user information; 在所述至少一个边界基站中,用于从所述第一移动交换机向所述第二移动交换机转换用户通信信号的设备;In said at least one border base station, means for switching subscriber communication signals from said first mobile exchange to said second mobile exchange; 在所述第二移动交换机中,利用所分配的资源以控制用户通信的设备;In the second mobile switch, using the allocated resources to control user communication equipment; 在所述第二移动交换机中,向所述多个移动站中相关的一个移动站通知半硬切换的设备;In said second mobile exchange, means for notifying an associated one of said plurality of mobile stations of a half-hard handover; 在所述第二移动交换机中,向所述第一移动交换机通告成功完成半硬切换的设备;In the second mobility switch, notifying the first mobility switch of devices that have successfully completed half-hard handover; 在所述第一移动交换机中,释放涉及用户通信的资源的设备。In said first mobile exchange, means for releasing resources related to user communication. 2.根据权利要求1的系统,其特征在于,这个系统是一个CDMA系统。2. A system according to claim 1, characterized in that the system is a CDMA system. 3.根据权利要求1的系统,其特征在于,这个系统是一个TDMA系统。3. A system according to claim 1, characterized in that the system is a TDMA system. 4.一种用于蜂窝通信系统的半硬切换方法,其中所述蜂窝通信系统包括:4. A semi-hard handover method for a cellular communication system, wherein the cellular communication system comprises: 多个移动站;multiple mobile stations; 一个第一移动交换机;a first mobile exchange; 一个第二移动交换机;a second mobile exchange; 多个基站,一个经一组所述多个基站,它只与所述第一移动交换机相连接,一个第二组所述多个基站,它只与所述第二移动交换机相连接,在所述多个基站中,至少有一个基站是一个边界基站,同时与所述第一移动交换机和第二移动交换机相连接;a plurality of base stations, one through a group of said plurality of base stations, which is only connected to said first mobile exchange, and a second group of said plurality of base stations, which is only connected to said second mobile exchange, in said Among the plurality of base stations, at least one base station is a border base station and is connected to the first mobile exchange and the second mobile exchange at the same time; 所述方法的特征在于,涉及进行中的用户通信的控制和信号分集合并功能,从所述第一移动交换机,切换到所述第二移动交换机,而不中断所述多个移动站中相关的一个移动站与所述至少一个边界基站之间的无线通信,半硬切换包括步骤:Said method is characterized in that control and signal diversity combining functions involving ongoing subscriber communications are handed over from said first mobile exchange to said second mobile exchange without interrupting associated ones of said plurality of mobile stations. A wireless communication between a mobile station and said at least one border base station, semi-hard handover comprising the steps of: 由所述第一移动交换机向所述第二移动交换机发出半硬切换的请求;sending a request for half-hard handover by the first mobility switch to the second mobility switch; 分配所述第二移动交换机所要求的控制和分集合并资源,以用于处理和控制所述进行中的用户通信;allocating control and diversity combining resources required by said second mobile exchange for processing and controlling said ongoing user communications; 在所述至少一个边界基站上,从所述第一移动交换机向所述第二移动交换机转换所述进行中的用户通信信号;at said at least one border base station, switching said ongoing subscriber communication signal from said first mobile switch to said second mobile switch; 利用所述分配的资源,由所述第二移动交换机控制所述进行中的用户通信;controlling said ongoing user communication by said second mobility switch utilizing said allocated resources; 向所述多个移劝站中相关的一个移动站通知半硬切换;notifying an associated one of the plurality of mobile stations of a semi-hard handoff; 向所述第一移动交换机通告成功完成半硬切换;Notifying the first mobility switch of the successful completion of the half-hard handover; 在所述第一移动交换机中,释放涉及所述进行中的用户通信的资源。In said first mobile exchange, resources related to said ongoing user communication are released. 5.根据权利要求4的方法,其特征在于,半硬切换应用于一个CDMA系统中。5. The method according to claim 4, characterized in that the semi-hard handover is applied in a CDMA system. 6.根据权利要4的方法,其特征在于,半硬切换应用于一个TDMA系统中。6. A method according to claim 4, characterized in that the semi-hard handover is applied in a TDMA system.
CN94194906A 1994-01-27 1994-01-27 Cellular communication system and its semi-hard handover method Expired - Fee Related CN1080979C (en)

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