CN1528100A - System and method for wireless code division multiple access communication - Google Patents

Abstract

A system and method for wireless code division multiple access communication includes a method and apparatus for assigning a time slotted code division multiple access carrier for wireless reverse link communication between a device and a base station. One or more performance characteristics corresponding to the device are determined. A code division multiple access spreading code is assigned based on the determined performance characteristics. A time slot for communication with the base sation is assigned based on the assigned spreading code. According to one aspect, the assigned spreading code corresponds to one of an SCDMA code and an ACDMA code such that a time slot corresponding to an SCDMA code provides a time slot in which the base station. An increase in channel gain and an increase in channel capacity result as compared with a system where time slots support mixed ACDMA and SCDMA codes.

Description

System and method for wireless code division multiple access communication

technical field

The present invention relates to a system and method for wireless communication of a reverse communication link (wireless device to base station), and more particularly to a system and method for wireless communication in a Code Division Multiple Access (CDMA) environment A method wherein communication slots and/or spreading codes are allocated for asynchronous operation and synchronous operation based on one or more performance characteristics.

Background technique

The success of wireless communications has created an increasing demand for new types of wireless devices, and for improvements in the quality of these devices. Such a requirement is no longer a requirement when wireless devices adapted to communicate over cell-based systems such as Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplexing (OFDM) systems are traditionally classified as telephones. question.

More specifically, wireless communication devices also include personal digital assistants (PDAs), pagers, network appliances (network appliances), laptops (laptops), and desktop computers. These devices and their use can be divided into three categories, namely mobile, nomadic, and stationary. A mobile device is a device that is moving during use, such as phones and personal digital assistants used while walking, traveling, etc. Stationary equipment refers to equipment that typically does not tend to move even when used repeatedly. An example of a stationary device is a personal tower computer with wireless communication capabilities. Nomadic equipment is equipment that can be moved from one place to another, but is typically stationary while in use. While typically stationary in use, nomadic devices may also be mobile in use. An example of a nomadic device is a laptop computer with wireless communication capabilities, where the laptop computer can be used in an office or moved to another location for subsequent use. According to this example, the laptop can still be used while being moved, for example when riding a train or a car.

Current wireless communication infrastructures also include one or more base stations for communicating with wireless devices, wherein the base stations are disposed in a network that provides access to external services, such as Internet access. As requirements change, infrastructure exists in the form of increasing base station and antenna density, and adding equipment to the system to increase the processing load placed on the base station communication equipment.

Currently proposed wireless communication environments, such as the 3rd Generation Partnership Project (3GPP), propose different designs for the different kinds of devices described above. The type of device becomes especially important when determining the design for the reverse link (device to base station). In particular, CDMA devices such as 3GPP propose two types of reverse link designs, Synchronous Code Division Multiple Access (SCDMA) and Asynchronous Code Division Multiple Access (ACDMA), so that devices on one type of link or Another type of on-link operation. However, 3GPP does not address the complementary use of SCDMA and ACDMA on the reverse link. Furthermore, neither the 3GPP nor the CDMA2000 communication environment addresses the complementary use of SCDMA and ACDMA depending on the type of equipment, fixed or mobile.

SCDMA refers to Synchronous Orthogonal Transmission in which each communication channel is identified by a different orthogonal spreading sequence and synchronization between channels is achieved by ensuring that transmissions arrive at each receiver at approximately the same time. In contrast, an ACDMA link is one in which transmissions arrive at the receiver at different times. Compared with the SCDMA link, the ACDMA link causes the loss of the orthogonality of the system, and increases the interference in the coverage area of each base station, that is, the cell.

As a result of the orthogonality of the SCDMA transmission, compared to that of an equivalent ACDMA link, a carrier to interference ratio (carrier to interference ratio) of approximately 3dB or higher quadrature gain. Since the capacity of the carrier channel increases when all devices operate synchronously, SCDMA is more ideally configured than ACDMA operation. However, the presence of devices that are time misaligned, ie not synchronized with other devices, increases interference in the channel, thereby reducing the capacity and performance of the channel. As discussed above, SCDMA links require time alignment between receivers and also require the use of orthogonal spreading codes such as Walsh spreading codes. Since the number of codes in an orthogonal spreading code environment is limited compared to non-orthogonal codes such as those used in ACDMA links, the number of devices that can be used simultaneously with a particular carrier within a cell is limited. This limitation makes the aspect of code distribution particularly important, thus increasing the complexity of the system.

An integral feature of the CDMA system is the concept of soft handover. Soft handover refers to the simultaneous communication between a wireless device and multiple base stations in order to transfer the communication from one base station to another in a make-before-break manner, that is, after disconnecting from the current base station. Establish communication with the new base station before the communication link of the new base station. Devices using SCDMA codes can maintain soft handoffs with other base stations, however, these other base stations see the SCDMA codes as ordinary pseudo-noise codes. Thus, a device in soft handoff increases the amount of interference experienced by SCDMA devices within the cell. Since precise time alignment, eg, within one-eighth or one-fourth chip, is required in high-capacity SCDMA systems, devices of the mobile type described above will be relative to other devices and base stations mobile, it is difficult for these devices to maintain synchronized operation on the reverse link. Furthermore, even for stationary use, the ability to maintain synchronization is affected by fading variations and interference. These adverse effects are especially prevalent in wideband (ie 5MHz and above) systems due to the very fast chip rates involved. As a result, some systems conforming to 3GPP standards propose different designs for devices with lower and higher mobility.

The category in which the device operates may change, for example, if the user of the mobile device stops moving for a prolonged period. However, current systems do not support switching between one category and another, ie ACDMA to/from SCDM reverse link operation. Mobile devices that become stationary can be classified as asynchronously operating with lower efficiency and lower capacity when, in fact, the device can efficiently utilize the SCDMA reverse link. Similarly, due to the increased channel interference imposed by a nomadic device changing from fixed to mobile operation due to its inability to maintain orthogonality, the device may adversely affect the performance of the originally assigned SCDMA reverse link.

Accordingly, it is an object of the present invention to propose a wireless communication system which enables devices to operate either as SCDMA reverse link or as ACDMA reverse link, depending on the particular conditions of the wireless device at the time of operation.

Furthermore, because current wireless communication systems do not facilitate switching from ACDMA to SCDMA operation and vice versa during a communication session, these current systems are not capable of monitoring the manner in which a device is operating in order to detect a change in the operating category of a device, such as a device Ability to maintain synchronization (degree of mobility). At the same time, current systems are not optimized for situations that limit the use of SCDMA codes.

It is therefore an object of the present invention to propose a system capable of monitoring the operating characteristics, ie the type of operation, of equipment in order to detect changes therein. This is particularly applicable in the case of multi-carrier broadband operation, where system providers allocate their broadband spectrum into multiple discrete carriers so that each carrier supports a specific type of operation, such as SCDMA or ACDMA.

Another object of the present invention is to propose a CDMA system in which, while providing mobile users with unrestricted use of ACDMA codes, the interference of devices operating in SCDMA mode is reduced in order to ensure an optimal system operate.

The use of multiple discrete frequency-division multiplexed (FDM) carriers described in U.S. Patent Application No. 09/797,273 allows individual carriers to support ACDMA and SCDMA codes, however, due to the need to provide Therefore, this method is not as effective as using a single large-bandwidth carrier to support both coding types at the same time. It is therefore another object of the present invention to propose a method of supporting SCDMA codes and ACDMA codes in a communication environment in which a single carrier of larger bandwidth is used as opposed to using multiple smaller carriers.

The additional capacity gain of SCDMA over ACDMA access is obtained at the expense of coding constraints. Thus, in the case of SCDMA access, the number of wireless devices that can access the base station at any one time is strictly limited. It is therefore an object of the present invention to propose a system and method that provides a method for reusing spreading codes within a cell (as used herein, a "cell" means a communication area supported by a base station) .

While ideal in theory, not all wireless devices in communication with a base station will be orthogonal to one another. This is due to many factors. First, channel conditions and/or speeds of wireless devices may constrain precise time alignment at the base station. Second, some users in the CDMA system will be in a soft handoff state. As a result, the time of arrival of the wireless device's signal may be time aligned with only one base station. Third, since there is a finite number of orthogonal spreading codes available at each base station, wireless devices communicating with the same base station can begin reusing these codes after they have been scrambled. Thus, to other wireless devices, these codes will appear as pseudo-noise codes. The result of this will be that some wireless devices' transmissions will be orthogonal to each other and some will not. Of course, the greater the number of wireless devices transmitting orthogonally to each other, the greater the capacity of the channel.

It is therefore an object of the present invention to propose a system and method that can optimize a wireless communication channel by grouping transmissions from wireless devices that are transmitting orthogonally to one another.

Many wireless systems include a radio resource manager ("RRM"), also known as a scheduler. Among other functions, RRM is used to manage the wireless communication channels of a base station or group of base stations by allocating time slots, frequencies and spreading codes to the wireless devices associated with the base station. Typically, assignments are made based on channel conditions such as channel quality (C/I ratio), however, assignments can also be made based on quality of service requirements, priority of wireless device communications, and/or round robin assignment strategies.

As used herein, a slot denotes a unit of time for allocation of shared transmission resources in the time domain. Typically, such time slots are very short, for example on the order of one millisecond. The device may be given transmission resources in one or more consecutive time slots. After this time interval has elapsed, another device may be given the same transmission resources. However, the transmissions from the two devices are separated in time because they are transmitted in different time slots. This way, these devices don't interfere with each other.

However, current RRM does not include support for tracking whether a time slot is assigned to a spreading code for ACDMA communications or to a spreading code for SCDMA communications. Known RRM is not yet able to group wireless devices into devices that use/need ACDMA communication and devices that use/need SCDMA communication, so as to allocate time slots that maximize channel capacity, wherein the devices that use/need ACDMA communication are not A wireless device communicates orthogonally with other wireless devices, whereas a device that uses/requires SCDMA communication is a wireless device that communicates orthogonally with other wireless devices. As a result, the time slots associated with a particular channel are allocated in a non-optimal manner, resulting in inefficient use of the channel and a reduction in channel and system capacity.

It is therefore another object of the present invention to propose a CDMA system in which the RRM can keep track of whether a time slot corresponds to a SCDMA code or an ACDMA code and group wireless devices such that for the purpose of time slot allocation, the Devices that operate in a manner that requires ACDMA codes are grouped together, as well as devices that operate in a manner that can use SCDMA codes for time slot allocation purposes, in order to maximize channel and system efficiency. Another object of the present invention is to propose a method and system which enable the limited spreading codes corresponding to SCDMA communications with base stations within a cell to be re-used, thereby remaining within a larger group of wireless devices Orthogonality of communication between them.

Contents of the invention

Advantageously, the present invention proposes radio resource management functionality to extend the number of available orthogonal codes by enabling code reuse and by allocating time slots to groups of devices that can benefit from using SCDMA codes.

Advantageously, the method proposed by the present invention can use a single carrier of larger bandwidth to support ACDMA and SCDMA codes, thereby avoiding the need to support multiple carriers using guard bands in between.

According to one aspect of the invention, the invention proposes a method for allocating time slots for wireless communication between a device and a base station, wherein one or more operating characteristics corresponding to the device are determined. According to the determined working characteristics, the spreading codes are allocated. The time slots for communicating with the base station are allocated according to the allocated spreading codes.

According to another aspect of the present invention, the present invention provides an apparatus for allocating time slots for wireless communication between a device and a base station, wherein the apparatus has a central processing unit. The central processing unit is used to determine one or more operating characteristics corresponding to the equipment, allocate spreading codes according to the determined operating characteristics, and allocate time slots for communicating with the base station according to the allocated spreading codes.

According to another aspect of the present invention, the present invention also proposes a communication signal included in a wireless communication medium between a device and a base station. The wireless signal has a plurality of time slots, wherein each of the plurality of time slots supports communication from a device to a base station using one of a synchronous code division multiple access code and an asynchronous code division multiple access code.

According to another aspect of the present invention, the present invention provides a method for selecting a set of spreading codes related to code division multiple access wireless communication between a device and a base station, wherein, selecting from a plurality of scrambling codes corresponding to the base station scramble. Select a code division multiple access spread spectrum code set from a plurality of code division multiple access spread spectrum code sets corresponding to the base station, so that the first combination of the first spread spectrum code set and the scrambling code produces the same combination as the second scrambling code set and The second combined orthogonal total code of the scrambling code.

Advantageously, the present invention proposes a system and method for wireless communication between a device and a base station with each other by using profile and reverse link coding techniques optimized according to the operational profile of the device. For example, a device in a stationary state may use an SCDMA link, while a mobile device may use an ACDMA link. Furthermore, the invention is arranged to monitor the synchronization of the device and the base station and, if a change in mobility is detected, such as from fixed to mobile operation, to switch the communication from the current carrier to the one whose CDMA code is suitable for the change. The carrier of the link in the mobility state.

According to another aspect of the present invention, there is provided a method for wireless communication between a device and a base station using a CDMA carrier, wherein an operating condition of the device is determined. The operating conditions include the degree of unit mobility. Based on the determined operating condition of the device, a first carrier is selected for CDMA communication from the device to the base station. A wireless communication link between the device and the base station is established using the first carrier.

According to another aspect of the present invention, the present invention proposes a device for wireless communication with a base station using at least one CDMA carrier, wherein the device has a transmitter and a central processing unit for effectively communicating with the transmitter. The transmitter transmits the first signal to the base station using the first designated carrier. The central processing unit determines an operating condition, selects a first specified carrier according to the determined operating condition, and uses the first specified carrier to establish a wireless communication link with the base station. The operating conditions include the degree of unit mobility.

According to another aspect of the present invention, the present invention proposes a wireless signal for communication between a device and a base station, wherein the wireless signal has multiple carriers. Each of the multiple carriers provides a synchronous code division multiple access communication link or an asynchronous code division multiple access communication link. Each carrier providing a synchronous code division multiple access communication link is used by a fixed wireless device and each carrier providing an asynchronous code division multiple access communication link is used by a mobile wireless device.

According to one aspect of the present invention, the present invention proposes a base station for receiving wireless communication from a device using at least one code division multiple access carrier, wherein the base station has a receiver and a central processing unit operatively in communication with the receiver. The central processing unit determines an operating condition of the device, selects a first designated carrier according to the determined operating condition, and establishes wireless communication with the device using the first designated carrier. The operating conditions include the degree of unit mobility. The receiver receives a first signal from the device using a first designated carrier.

Description of drawings

A more complete understanding of the invention and its attendant advantages and features will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings:

Fig. 1 is the block diagram of the communication system constructed according to the principle of the present invention;

FIG. 2 is a layout diagram of a multi-carrier system constructed according to the principle of the present invention;

Fig. 3 is a block diagram of the wireless communication part of the device constructed according to the principles of the present invention;

Fig. 4 is a block diagram of the wireless communication part of the base station constructed according to the principle of the present invention;

Figure 5 is a flowchart of the overall operation of the system and communication unit;

Fig. 6 is a flowchart of a new carrier selection process;

Fig. 7 is an optional hardware layout diagram constructed according to the principle of the present invention;

Figure 8 is a diagram showing a cell of a typical complete code arrangement in accordance with the principles of the present invention;

Fig. 9 is the arrangement diagram of the timeslot of communication channel;

Figure 10 is a table of typical time slot allocation;

Figure 11 is a table of selectable typical time slot allocations; and

Fig. 12 is a graph of sampling performance evaluation under typical test cases.

Detailed ways

Referring now to the drawings, wherein like reference numerals indicate like elements, there is shown in FIG. 1 a communication system constructed in accordance with the principles of the present invention and generally designated 10 . The communication system 10 preferably includes one or more wireless devices 12 (shown as a handheld device 12a, a wireless tower computer 12b, a wireless car phone 12c, and a wireless Laptop 12d). Device 12 and base station 14 are generally referred to together as a "unit".

Handheld wireless device 12a is an example of a mobile device, wireless tower computer 12b is an example of a stationary device, vehicle-mounted wireless phone 12c is an example of a mobile device, and wireless laptop 12d is an example of a nomadic device. Of course, since the hand-held wireless device 12a and the vehicle-mounted radiotelephone 12c can be operated both when the user (or vehicle) is stationary and when the user (or vehicle) is moving, they can also be viewed as swimming equipment. However, since devices 12a and 12c are typically in motion when in use, they are considered mobile in this discussion. Communication system 10 also includes a base station communication network 18 connected to base station 14 by communication link 20 . Communication network 18 may employ any arrangement to facilitate communication between base stations 14 themselves and/or external services such as Internet access, news and stock quote services, etc. (not shown).

Arrangements such as communication network 18 and communication link 20 are known to support digital wireless networks. For example, communication link 20 may be a wireless link such as a multi-megabit-per-second link or a wired link. Communications network 18 includes digital switches, routers, or other known digital communications equipment.

Device 12 is any wireless communication device, not limited to the four types of devices shown in FIG. 1 . Each of the devices 12 includes a wireless communication part for receiving wireless communication signals from the base station 14 and transmitting wireless communication signals to the base station 14, which will be described in detail below.

Wireless communication network 16 is preferably a broadband system. As used herein, the term "wideband" refers to systems with a minimum bandwidth of 5 MHz. Preferably, the broadband system is arranged as a multi-carrier system, wherein a wireless communication link between devices 12 and/or base station 14 is established by using one of the carriers in the multi-carrier system. Figure 2 shows an arrangement diagram of a multi-carrier system for the reverse link constructed in accordance with the principles of the present invention. As shown in FIG. 2, the multi-carrier system 22 includes multiple carriers, namely carrier A 24a, carrier B 24b, and carrier C 24c. Although FIG. 2 shows adjacent carriers, the invention is not so limited.

For example, multi-carrier system 22 may be configured as a 5MHz system, where each of carriers A to C (24a, 24b, and 24c) is a 1.25MHz carrier channel. As discussed in detail below, each carrier is used to support a particular link setup, such as ACDMA and SCDMA wireless communication links, appropriate to the particular characteristics of the devices using the carrier. Thus, in accordance with the principles of the present invention, carrier A 24a can be used to support the ACDMA reverse link, while carrier B 24b can be used to support the SCDMA reverse link.

It is contemplated that wireless communication network 16 may be included as part of any wireless communication system including wireless high speed fixed access data systems employing wireless high speed data protocol (HDP) or wireless digital subscriber line (DSL) signals . Additionally, it is contemplated that wireless communication network 16 may be included as part of a wireless local area network. Standard protocols are known for providing wireless high speed data protocols, wireless DSL signals, and wireless local area network signals. As used herein, the term "protocol" refers to the arrangement of data within a data packet, such as packet header, packet footer, packet size, and the like.

Fig. 3 is a block diagram of the wireless communications portion of device 12 constructed in accordance with the principles of the present invention. As shown in Figure 3, preferably, the wireless communication part of the device 12 includes a device receiver 26 and a device transmitter 28, each of the device receiver and the device transmitter is connected to the device central processing unit 30, and is received by the device Control of the central processing unit 30 . The device receiver 26 and the device transmitter 28 are connected to an antenna 32 for receiving signals from and transmitting signals to other units, respectively.

Preferably, a device receiver 26 is provided for receiving signals transmitted by the base station 14 . Preferably, the device transmitter 28 is configured to transmit CDMA spread spectrum signals such as ACDMA and SCDMA spread spectrum signals to the base station 14 through the antenna 32 . The device central processing unit 30 is any central processing unit capable of performing the device functions described in detail below.

According to the present invention, it is preferred that the central processing unit 30 of the device provided includes or has access to sufficient memory (not shown) required to store data, buffer, transmit and receive data and program code in order to execute specified , the functions described below. In addition, it is preferable that the device central processing unit 30 is configured to enable the device to switch between carriers of the multi-carrier system. This is the case regardless of whether the device 12 determines whether a carrier switch is required, or whether to perform a carrier switch, in accordance with instructions received from another unit, such as the base station 14 .

Depending on the operating conditions of the device, device 12 may operate to communicate with base station 14 by using either SCDMA or ACDMA communications on the reverse link, and may operate to communicate between ACDMA and SCDMA communication links by using an appropriate carrier switching protocol. switching between channels, wherein the carrier switching protocol is typically used to change the carrier in multi-carrier wireless communication.

Figure 4 is a block diagram of a base station 14 constructed in accordance with the principles of the present invention. As shown in Figure 4, preferably, the base station 14 includes a base station receiver 34 and a base station transmitter 36, wherein each of the base station receiver 34 and the base station transmitter 36 is connected with the base station central processing unit 38, and is received by the base station Control of the central processing unit 38 . Additionally, base station 14 preferably includes a base station antenna subsystem 40 coupled to base station receiver 34 and base station transmitter 36 to receive signals transmitted by device 12 and to transmit signals to device 12, respectively.

Preferably, the base station 14 further includes a base station link 42 , and the base station link 42 sets required interface hardware and/or software so that the base station 14 is connected to the communication network 18 through the communication link 20 . The interface hardware takes the form of plugs, sockets, and electronic circuit elements. When executed, the interface software provides the drivers and other functions needed to receive data from, and transmit data to, the communication network 18 .

Preferably, a base station receiver 34 is provided for receiving wireless spread spectrum CDMA signals, such as ACDMA and SCDMA signals, from the plurality of devices 12 . In addition, the base station 14 transmits time alignment commands to the devices 12 to instruct the devices 12 to adjust their transmission timing so as to maintain a synchronous alignment when transmitting. Techniques are known for determining and transmitting time alignment commands in a wireless communication environment.

Preferably, the base station central processing unit 38 includes or accesses a storage unit (storage unit), wherein the storage unit includes program instructions required to execute the functions described below. In addition, it is preferable that the provided storage unit stores data corresponding to the ongoing communication of the device 12, and provides buffering for data transmitted to and received from the device 12 and the communication network 18, etc. . In general, any central processing unit capable of providing the described functionality of the base station 14 may be used.

In the case of device 12 and base station 14, each of the elements of the respective devices described above is provided using a communication structure that facilitates communication between the respective elements. Furthermore, it is contemplated that the combination of elements of each of the individual devices 12 and base station 14, such as the receiver, transmitter, and central processing unit, may be provided as a single semiconductor integrated circuit.

In accordance with the present invention, each base station 14 is capable of communicating with a device 12 by using one carrier, or a combination of multiple carriers in a multi-carrier environment. Additionally, each base station 14 operates to determine whether to communicate with device 12 via the ACDMA link or via the SCDMA link, particularly on the reverse link, based on one or more operating condition characteristics. These characteristics include whether the device is mobile or stationary, and whether there are sufficient orthogonal spreading codes available for SCDMA operation.

The overall operation of system 10 and communication units is explained with reference to FIG. 5 and described with reference to communication between device 12 and base station 14 .

Initially, the operating condition of device 12 is determined, preferably by base station 14 (step S100). The operating condition includes characteristics representing the degree of movement of the device. The degree of mobility may take the form of a binary determination such as stationary or mobile, or may be determined for a specified degree of mobility and included as an operating condition. Known techniques determine a given degree of mobility by estimating the velocity of the mobile device 12 from changes in the timing of signals received at the base station. Initially, the velocity can be estimated using the access channel or the signaling channel on either the SCDMA carrier or the ACDMA carrier. Base station 14 estimates the degree of movement of device 12 by tracking the frequency of time alignment changes transmitted to device 12 . Thus, if the mobility is smaller than a predetermined value, the degree of mobility may be set to be fixed, or if the mobility is greater than a predetermined value, the degree of mobility may be set to be mobile. The predetermined value is preferably based on the chip rate and the resulting capabilities of the base station 14 in order to maintain the SCDMA link with the device 12 .

It is also contemplated that device 12 may determine its own degree of mobility and provide this determination to base station 14 . For example, device 12 may be equipped with a tracking system, such as a global positioning receiver, that determines changes in the position of device 12 over time, ie, velocity.

Depending at least in part on operating conditions, a carrier is selected for the communication link between device 12 and base station 14 (step S102). Preferably, the carrier is selected by the base station 14 from carriers in a multi-carrier environment dedicated to SCDMA spread spectrum communication links and ACDMA spread spectrum communication links. It should be appreciated that device 12 may also select a carrier. Hereinafter, the carrier selection process will be discussed in detail.

A communication link is established using the selected carrier (step S104), and data communication between the device 12 and the base station 14 is started using the selected carrier (step S106). Establishing a communication link as an ACDMA communication link is performed using those facilities that the system provides for ACDMA communication. For example, a system supporting a mobile device on a carrier used to support an ACDMA communication link may use a "soft handoff" technique between a mobile device, such as a wireless car phone 12c, and a plurality of base stations 14.

Data communication continues for the duration of the communication session, ie call, data transfer, etc., until the communication session is terminated, or a change in the operating conditions of the device 12 is detected (step S108).

A change in operating conditions in the device 12 is detected in a manner similar to the manner in which the initial operating conditions were determined as described for step S100 above. In particular, base station 14 may determine the degree of mobility of device 12, and/or devices 12 may determine their own degree of mobility. For example, a nomadic device such as laptop 12d may have established communications based on its initial operating conditions reflecting a stationary state. Laptop 12d may start to move, thereby effecting a change in its operating state from stationary to mobile. For example, it may be the case that the laptop 12d is initially operated on a train or car that is not moving, and then the train or car starts to move. When a change in the operating condition is detected (step S108), a possible new carrier is selected according to the change (step S110). The new carrier is preferably a carrier within a multi-carrier broadband communication environment. As will be discussed in detail below, a change in the operating conditions of a device does not necessarily result in the selection of a new carrier. For example, it is the case that in the reverse SCDMA link supported by the new carrier, there is no spreading code available. While it is preferred that the base station 14 select the new carrier, it is contemplated that the device 12 could select the new carrier and provide the base station 14 with the new carrier information.

As in step S104, a communication link is established using a new carrier (step S112). Known techniques allow switching between wireless carrier frequencies without terminating a communication session. Monitoring for changes in operating conditions for subsequent new carrier selection continues at steps S108 to S112 until the communication session is completed (step S114).

Referring to the flowchart shown in FIG. 6 , the new carrier selection process in steps S102 and S110 will be described. The operating conditions are evaluated to determine whether the equipment is stationary or moving faster than a predetermined amount. If the equipment is fixed (step S116), and a spreading code such as an orthogonal Walsh spreading code is available on one or more carriers supporting SCDMA (step S118), then select a carrier with an SCDMA channel (step S120). This is the case for fixed wireless devices such as wireless tower computer 12b. If there is no spreading code available, a carrier with an ACDMA channel is used (step S122).

Similarly, for devices that are not normally stationary (step S116), but are not currently mobile (step S124), a carrier with an SCDMA channel is selected if a spreading code is available. If there is no spreading code available, a carrier with an ACDMA channel is selected.

Devices classified as currently mobile (step S124), ie not stationary, or having a degree of mobility greater than a predetermined amount, such as wireless telephone 12a and vehicular wireless device 12c, use a carrier with an ACDMA channel (step S122).

Note that the operating condition preferably indicates whether the equipment is stationary or mobile. However, it is contemplated that the operating condition may indicate that the device is nomadic by storing the device's mobility history. The movement history is used to predict the initial operating characteristics of the equipment as stationary or mobile. As discussed above, devices that are typically stationary when in use, but are also suitable for use while moving, are typically referred to as nomadic devices.

A device 12 using SCDMA codes can maintain soft handover with base stations other than its primary base station 14, however, these other base stations 14 can use the SCDMA codes as the Combine the common pseudo noise codes generated to receive.

For example, a device 12 associated with a base station 14 (referred to herein as base station A) as the primary link has a code C1 from an SCDMA OVSF (Orthogonal Variable Spreading Factor) tree or set of orthogonal codes, and a The associated scrambling code S1. When device 12 enters a soft handoff with another base station 14 (referred to as base station B at this time) with its own scrambling code S2, the transmission from device 12 to base station A uses SCDMA, while the received The same transmission becomes like another pseudonoise code. Thus, device 12 in SCDMA mode can maintain soft handover with other base stations, but if these base stations do not have the same scrambling code (such an arrangement is suitable for cell sites that are divided into sectors), device 12 cannot The base station operates in the manner of SCDMA. Therefore, the SCDMA mode device in soft handover will appear as interference to the SCDMA device whose primary base station is base station B since they operate in the same carrier frequency.

Since the codes of these devices will be seen as pseudo-noise codes by the non-primary base stations, the device 12 in soft handover can migrate to the ACDMA carrier first, and thus, the device 12 can become a cell for those in these base stations (without soft handover). handover) the source of interference for SCDMA code users.

Advantageously, the present invention provides a multi-carrier environment in which communication links, particularly reverse links, are established and maintained such that the type of link selected is the optimal link for the device depending on the operating conditions of the device. In addition, the type of communication link is changed when a change in operating conditions necessitates a change in the link type, eg, when a nomadic device using an SCDMA link begins to move such that ACDMA operation is preferred. As another example, when a device using an SCDMA code needs to enter a soft handoff, a change to the link can be made.

The present invention provides a method for obtaining synchronization of a device 12 by measuring a signal received at a secondary base station (secondary base station) 14 during soft handover. If the device 12 is handed over to one of the secondary base stations 14 (since its pilot becomes the strongest signal available), synchronization information can be easily obtained, allowing the device 12 to immediately switch from the SCDMA code benefit from its use.

Thus, the present invention advantageously provides a multi-carrier environment that can support both lower mobility devices and higher mobility devices, thereby accommodating devices whose mobility varies while in use. Dividing the available bandwidth among several subcarriers reduces the chip rate used per carrier. A lower chip rate makes it easier to establish and maintain the time alignment required for SCDMA operation. Decoupling the adverse effects of devices that are able to efficiently use the SCDMA carrier, ie low mobility devices, from those that are not able to maintain time alignment, ie high mobility devices. It may be recalled that the strict time alignment requirements for SCDMA operation and the lack of synchronization in all secondary base stations in soft handover would reduce the advantages of SCDMA operation.

Since the present invention is preferably configured as a multi-carrier broadband system, individual carriers can be configured and reconfigured to provide the optimum carrier type assignment for the system environment. For example, a 5 MHz multi-carrier system supporting three 1.25 MHz carriers can be set up so that the ratio of SCDMA carriers to ACDMA carriers is suitable for the system and system users. For example, if the system supports more fixed devices than mobile devices, such as might occur in an office park, the system provider may allocate two carriers for SCDMA operation and one carrier for ACDMA operation. If the fixed-to-mobile allocation changes, the provider can reconfigure the system to provide more ACDMA carriers and fewer SCDMA carriers, or vice versa if desired. In addition, the flexibility of the present invention enables the provider to optimize the carrier allocation ratio on the basis of the system bandwidth or on the basis of each cell/sector according to the provider's needs and requirements for system configuration. The invention solves the problem of complementary use of SCDMA codes and traditional pseudo-noise ACDMA codes on the reverse link of the wireless communication system. As mentioned, SCDMA differs from ACDMA codes in that SCDMA codes are orthogonal codes that are only able to tolerate small chip time alignment deviations, thus requiring fairly precise chip synchronization. When SCDMA is applied to the reverse link of devices distributed over an area of a cell/sector, SCDMA codes can minimize interference within a cell, thus resulting in an increase in capacity. However, if synchronization cannot be maintained within the designed tolerances, the performance of SCDMA codes degrades well to that of ACDMA codes. Furthermore, when synchronization cannot be maintained, it is more advantageous to use ACDMA since it is not subject to the previously described quantity limitations relative to SCDMA codes. In this regard, the present invention provides two access methods for the reverse link, wherein the method most suitable for the operating conditions of the equipment is selected so as to maximize the benefits derived from the ACDMA and SCDMA access methods. The result is an increase in the capacity of the unit and the system.

In the above-described aspects of the invention, frequency division multiplexing (FDM) is employed to create separate communication channels for ADCMA communication and SCDMA communication. The smaller bandwidth reduces the multipath resolution of the RAKE receiver in the base station since this arrangement uses a smaller bandwidth carrier for each channel compared to a larger single channel.

However, the object of the present invention is to propose a wireless communication environment for supporting both SCDMA communication and ACDMA communication within a system and a cell, which is more efficient due to the elimination of the need for setting guard bands between adjacent channels. Easier to manage than FDM systems and more efficient than FDM systems. Furthermore, the wireless communication environment provides a more efficient way to support soft handover than can be achieved in FDM systems. Such a method and system are provided by another aspect of the invention. This optional aspect is now described.

Figure 7 shows an example of a hardware arrangement for this alternative arrangement. Figure 7 is similar to the arrangement shown in Figure 1 with the addition of a Radio Resource Manager 44 (hereinafter "RRM"). RRM 44 is shown connected to base station 14 . However, the RRM 44 may be included within the physical confines of the base station 14, or may be connected to other elements of the base station 14 via remote network connections. In other words, the physical location and placement of the RRM 44 is not important as long as the functionality provided by the RRM 44 is available for the corresponding base station 14. Furthermore, although FIG. 7 shows one RRM 44 for each base station 14, it should be appreciated that a one-to-one relationship between base stations and RRMs is not required. In this way, the RRM 44 can be configured to support one or more base stations 14.

The RRM 44 is a general-purpose or special-purpose computer configured to perform the functions described below by executing program software codes. One of ordinary skill in the art can appropriately size the computational performance and memory storage capacity of RRM 44 to support the desired number of devices 12 and base stations 14. RRM 44 preferably includes one or more volatile storage devices such as random access memory, nonvolatile storage devices such as read-only memory, and/or fixed disks for storing program software code; for executing program a central processing unit for the software code; and an interface connecting the RRM 44 with one or more other elements of the base station 14.

In addition to the functions performed by the RRM 44, such as code allocation, which are known to those skilled in the art, the RRM 44 arranged according to the present invention includes a number of added aspects, namely, in terms of orthogonal and/or soft handover operation, management The ability to reuse codes, and the ability to manage time slots for communication channels. Next, each of these added functions will be described in detail.

It should be noted that although the code reuse and slot management functions are described as added functions performed by the base station 44, it is contemplated that one or more of these added functions may be implemented as part of a stand-alone RRM 44 . In other words, more than one RRM 44 can be used to support a base station 14, such that existing RRM functionality can be maintained on an existing RRM 44, while implementation by an additional new RRM 44 supporting the same base station is described as Added functionality that is part of the present invention. In this way, updates to the program software code and retrofitting of the device can be avoided. Of course, those of ordinary skill in the art will know that the described functionality can be implemented as part of a new program software code version and installed into an existing RRM 44.

First, the code reuse feature of the present invention will be described. As mentioned above, one advantage of orthogonal communication is that the capacity of the communication channel is increased. A packet-based system using SCDMA applications in the uplink provides a gain of 3dB to 9dB compared to an unsynchronized CDMA system. However, the advantage of increasing the channel's capacity is adversely affected by the limited number of scrambling codes available for SCDMA channels. The present invention solves this problem.

Typically, a full spreading code used in a CDMA system includes a scrambling code and a spreading code. The scrambling code is part of a common complete code for a particular base station and is also used to identify the set of spreading codes used. This portion of the complete code is managed by the RRM 44 and allocated to each device 12 communicating with the corresponding base station 14. The spreading code is part of a complete code assigned by the RRM 44 to a particular wireless device 12 and is used to identify communications received from the wireless device 12. The codes assigned to wireless devices 12 communicating in SCDMA as orthogonal codes are the spreading code portion of the complete code, and as discussed above, these orthogonal spreading codes are finite. By associating multiple scrambling codes with a base station, orthogonal spreading codes can be reused in a manner that provides quasi-orthogonality, thereby increasing the number of in-cell The capacity of SCDMA.

Referring to FIG. 8, an example of the multiple scrambling code allocation and management features of the present invention will be described. FIG. 8 shows an example of a cell 46 corresponding to base station 14 in FIG. 7 . Cell 46 supports two scrambling codes, identified as S1 and S2, and a set of two spreading codes as C1 and C2. As shown in Figure 8, the permutation of two scrambling codes and two orthogonal spreading codes produces four different complete codes. Of course, the present invention is not limited to the case where there are two sets of scrambling codes and two spreading codes in each cell. Any number of sets of scrambling and spreading codes may be used in each cell depending on the capacity requirements of the cell.

In particular, complete code 48 includes scrambling code S2 and orthogonal spreading code set C1; complete code 50 includes scrambling code S2 and orthogonal spreading code set C2; complete code 52 includes scrambling code S1 and orthogonal spreading code set C2 ; Complete code 54 includes scrambling code S1 and orthogonal spreading code set C1. Complete codes using the same scrambling code are orthogonal to each other, but not to other scrambling codes within cell 46 . Thus, the complete codes within the rectangle shown in FIG. 8 are mutually orthogonal (complete codes 48 and 50), and the complete codes within the oval shown in FIG. 8 are mutually orthogonal (complete codes 52 and 54). However, full codes 48 and 50 are not orthogonal to full codes 52 and 54 . As a result, quasi-orthogonality is formed between the complete codes within the cell 46 .

The quasi-orthogonality enables the same set of orthogonal spreading codes to be reused in the cell to increase capacity within the cell to support additional devices 12 operating in SCDMA mode. The RRM 44 also manages the communication channel by providing instructions to each wireless device 12 as to how many transmission frames the device 12 may use to transmit, or the duration for which the device 12 may transmit using an assigned full code. By managing the number of frame communications and the duration of transmissions, combined with the re-use of spreading codes, the capacity of wireless devices in each cell 46 is greatly increased compared to known CDMA systems.

As discussed above, the complete codes using the same scrambling code within the cell 46 are mutually orthogonal. Thus, by allocating these orthogonal complete codes to specific time slots, the orthogonality within each time slot can be maintained. Figure 9 shows a communication channel 56 divided into a number of time slots, namely slots X, Y through slot Z. Methods of dividing a CDMA communication channel into time slots are known. Within cell 46, RRM 44 allocates time slots for uplink communications from wireless devices 12 to base stations 14. Each time slot supports communications from one or more wireless devices 12 .

Figure 10 shows an example of time slot allocation. The slot table shown in FIG. 10 includes two slots, namely slot X and slot Y. Only two time slots are described for simplicity, it being understood that a similar table could be constructed which includes all time slots for a given channel managed by the RRM 44. Slot X supports devices A, C, E, and G as shown. Slot Y supports wireless devices B, D, F, and H. FIG. Although there is no need to account for factors such as soft handover and multipath fading as described above, the wireless devices assigned to each communication slot are preferably mutually orthogonal to the devices assigned to the same slot. to communicate. For example, one of time slot X or time slot Y may be assigned to each of the devices 12 assigned the full codes of the full code 48 and the full code 50 described in FIG. 8 . However, due to reasons such as multipath fading described above, or wireless devices in soft handoff that can only synchronize at one base station, it is not possible to assign orthogonal spreading code. Similarly, devices 12 that were previously assigned the same time slot according to their capabilities and operated orthogonally may not now operate orthogonally.

As an example, in FIG. 10, devices determined by the RRM 44 that are not operating orthogonally are shown by the bolded orthogonality indicators. Thus, as shown by the example in FIG. 10, devices C and G in time slot X, and devices B and F in time slot Y are not operating orthogonally. The result is a reduction in channel gain, and thus a reduction in channel capacity. By monitoring channel conditions, the RRM 44 reallocates time slots by grouping devices 12 that together can benefit from the use of orthogonal codes in order to optimize channel capacity. An example of the regrouping is shown in FIG. 11 and described with reference to FIG. 11 . Channel conditions may be monitored, for example, by determining received signal strengths of previously scheduled transmissions, or in terms of signaling channels that may be used to maintain ongoing low data rate signaling connections between devices and base stations.

As shown in Figure 11, time slot X has been allocated by RRM 44 to devices that can benefit from orthogonal communication, such as devices that are not in soft handover. In the example shown in FIG. 11, devices A, D, E, and H are all such devices. Spread spectrum and orthogonal codes in mutually orthogonal complete codes are assigned to these devices, wherein the complete codes are such as complete codes 48 and 50 or complete codes 52 and 54 shown in FIG. 8 . Devices that cannot benefit from the limited use of orthogonal codes are grouped together in another slot, such as slot Y including wireless devices B, C, F, and G shown in FIG. 11 . Wireless devices B, C, F, and G may be soft handoff devices with one or more other base stations. Since a device in soft handoff may be synchronized, ie, time aligned with only one base station, a device in soft handoff may not be time aligned with other devices supported within cell 46 . Thus, by combining all non-time-aligned devices and allocating a single time slot, the lack of gain observed in slot Y can be compensated by the gain provided by combining orthogonal devices in slot X make up.

Figure 12 shows a sample performance evaluation for a typical test case, where the maximum number of users (capacity) in each cell is expressed as a function of the percentage of synchronous (SCDMA) users. When all users are in ACDMA mode (not synchronized), it can accommodate 32 users. On the contrary, when all users are in SCDMA mode, the cell capacity is 44 users (a 38% increase over the capacity of the ACDMA case). The partially orthogonal situation shown in FIG. 10 can be represented by a scenario where 50% of the users are ACDMA users and 50% of the users are SCDMA users. In this case, the cell capacity is 37 users, which can be increased to 44 users ( 19% increase in capacity over the partially orthogonal case). It should be noted that the test results are only applicable to typical test cases, and the capacity gains of other scenarios may be greater or less than the numbers given here.

By managing code reuse and/or slot allocation as described above, partitioning of wireless devices using SCDMA codes versus using ACDMA codes is simpler than requiring the use of FDM to do the same partitioning. Advantageously, the present invention provides for an RRM function that extends the number of orthogonal codes available within a cell 46, in part based on requirements such as channel conditions and soft handover. By reusing these codes in order to achieve a quasi-orthogonal environment, and by grouping SCDMA communication devices in one or more time slots as opposed to assigning time slots based on the ability to benefit from orthogonal code (SCDMA) codes This can be achieved by increasing the capacity within these time slots (a gain of 10dB within a time slot equals a capacity increase of approximately 8×(8 times)) compared to the case.

Since packet-based systems typically have an RRM 44 to allocate resources to wireless devices, the present invention provides these advantages without adding complexity to the design of the system. Thus, the present invention advantageously provides an arrangement under which the existing RRM 44 will The operating characteristics of the device 12 such as the operating conditions described above, as well as adverse channel conditions, ie multipath interference, and soft handoff operation are considered.

Advantageously, the present invention also provides a method by which ACDMA and SCDMA codes can be supported by using a single, larger bandwidth carrier, thereby avoiding the need to use guard bands to support multiple carriers.

Those skilled in the art will appreciate that the present invention is not limited to what has been particularly shown and described above. Furthermore, it should be noted that all drawings are not drawn to scale unless otherwise indicated. Various modifications and changes may be made in light of the above teachings without departing from the scope and spirit of the invention as defined in the appended claims.

Claims (64)

1. one kind is the allocated for wireless communication time slot method between equipment and the base station, comprising:

Determine one or more operating characteristic corresponding with described equipment;

According to determined one or more operating characteristic, distribute spreading code; And

According to the spreading code that distributes, distribute time slot, so that communicate with the base station.

2. method according to claim 1 is characterized in that: the spreading code of distribution is corresponding to one of them of S-CDMA sign indicating number and Asynchronous Code Division Multiple Access sign indicating number.

3. method according to claim 1 is characterized in that: at least one operating characteristic is corresponding to operating in soft handover.

4. method according to claim 1 is characterized in that: also comprise:

Distribute scrambler, described scrambler is used to discern the base station, and discerns the spreading code set of described spreading code correspondence; And

Distribute all-key, complete code comprises the spreading code of distribution and the scrambler of distribution.

5. method according to claim 4 is characterized in that: the base station has corresponding a plurality of scramblers, wherein, selects the scrambler that is distributed from a plurality of scramblers.

6. method according to claim 5 is characterized in that: the base station has corresponding a plurality of spreading code set, wherein, selects the spreading code that is distributed from a plurality of spreading code set.

7. method according to claim 6 is characterized in that first combination results of first spreading code set and scrambler, makes up the complete code of quadrature with second of set of second spreading code and scrambler.

8. method according to claim 1 is characterized in that: also comprise:

According to the variation of the operating characteristic of equipment, the spreading code of distributing to equipment and at least one in the time slot are redistributed.

9. one kind is the equipment of the allocated for wireless communication time slot between equipment and the base station, and this equipment comprises:

CPU, described CPU operate so that:

Determine one or more operating characteristic corresponding with equipment;

According to determined one or more operating characteristic, distribute spreading code; And

According to the spreading code that distributes, distribute the time slot that communicates with the base station.

10. equipment according to claim 9, it is characterized in that: also comprise communication interface, described communication interface can effectively be communicated by letter with CPU, and can so that with the communicating by letter of base station, wherein, the described CPU time slot that will distribute to the base station that is used to transmit offers described equipment.

11. equipment according to claim 9 is characterized in that: the spreading code of distribution is corresponding to one of them of S-CDMA sign indicating number and Asynchronous Code Division Multiple Access sign indicating number.

12. equipment according to claim 9 is characterized in that: at least one operating characteristic is corresponding to operating in soft handover.

13. equipment according to claim 9 is characterized in that: CPU also operate so that:

Distribute scrambler, described scrambler is used to discern the base station, and the identification spreading code set corresponding with described spreading code; And

Distribute all-key, described complete code comprises the spreading code of distribution and the scrambler of distribution.

14. equipment according to claim 13 is characterized in that: the base station has corresponding a plurality of scramblers, and wherein, CPU is also operated so that distribute scrambler from a plurality of scramblers.

15. equipment according to claim 14 is characterized in that: the base station has corresponding a plurality of spreading codes set, and wherein, CPU is also operated so that distribute spreading code from one of them of a plurality of spreading codes set.

16. equipment according to claim 15 is characterized in that: first combination results of first spreading code set and scrambler, make up the complete code of quadrature with second of set of second spreading code and scrambler.

17. equipment according to claim 9 is characterized in that: also comprise:, the spreading code of distributing to described equipment and at least one in the time slot are redistributed according to the variation of the operating characteristic of equipment.

18. the signal of communication in the wireless communication medium that is included between equipment and the base station, described wireless signal comprises a plurality of time slots, in a plurality of time slots each passes through to use one of them of S-CDMA sign indicating number and Asynchronous Code Division Multiple Access sign indicating number, supports the communication of slave unit to the base station.

19. one kind be used to select with equipment and base station between the method for the relevant spreading code set of CDMA radio communication, this method comprises:

From a plurality of scramblers corresponding, select scrambler with the base station; And

From a plurality of CDMA spread spectrum sign indicating number set corresponding, select the set of code division multiple access spreading code with the base station,

Wherein, first combination results of first spreading code set and scrambler makes up the complete code of quadrature with second of set of second spreading code and scrambler.

20. method according to claim 19 is characterized in that: the CDMA spread spectrum sign indicating number is the S-CDMA spreading code.

21. one kind is the method for the radio communication employing code division multiple access carrier wave between equipment and the base station, comprising:

Determine the operating conditions of equipment, described operating conditions comprises the cell moving degree;

According to the operating conditions of determined equipment, select first carrier, so that carry out the wireless code division multiple access communication of slave unit to the base station; And

Use first carrier between equipment and base station, to set up wireless communication link.

22. method according to claim 21 is characterized in that: also comprise:

The variation of the operating conditions of checkout equipment;

According to the variation of the operating conditions of equipment, select second carrier wave, so that carry out the wireless code division multiple access communication of slave unit to the base station; And

Use second carrier wave, set up the wireless communication link of slave unit to the base station.

23. method according to claim 22 is characterized in that: one in the first carrier and second carrier wave provides the Asynchronous Code Division Multiple Access communication link, and another in the first carrier and second carrier wave provides synchronous code division multiple access communication chain.

24. method according to claim 23 is characterized in that: the selection of second carrier wave also depends on the quantity of available S-CDMA spreading code.

25. method according to claim 24 is characterized in that: if the quantity of available S-CDMA spreading code less than predetermined quantity, then second carrier wave of Xuan Zeing is corresponding to the Asynchronous Code Division Multiple Access link.

26. method according to claim 23, it is characterized in that: mobile degree is corresponding to mobile one of them with stationary state, wherein, if mobile degree is corresponding to mobile status, then second carrier wave provides the Asynchronous Code Division Multiple Access communication link, if and mobile degree is corresponding to stationary state, then second carrier wave provides synchronous code division multiple access communication chain.

27. method according to claim 21, it is characterized in that: mobile degree is corresponding to mobile one of them with stationary state, wherein, if mobile degree is corresponding to mobile status, then first carrier provides the Asynchronous Code Division Multiple Access communication link, and, if mobile degree corresponding to stationary state, then first carrier provides synchronous code division multiple access communication chain.

28. method according to claim 27, it is characterized in that if the speed of equipment less than predetermined amount, then mobile degree is fixed.

29. method according to claim 26 is characterized in that: if the speed of equipment less than predetermined amount, then mobile degree is fixed.

30. method according to claim 21 is characterized in that: there are a plurality of wireless code division multiple address carrier waves.

31. method according to claim 21 is characterized in that: the cell moving degree is determined by the base station.

32. method according to claim 31, it is characterized in that: first carrier provides one of them of Asynchronous Code Division Multiple Access communication link and synchronous code division multiple access communication chain, and second carrier wave provides another in Asynchronous Code Division Multiple Access access communications link and the synchronous code division multiple access communication chain.

33. method according to claim 21 is characterized in that: mobile degree is corresponding to mobile one of them with stationary state.

34. method according to claim 21 is characterized in that: by the history of the mobile degree of one of them memory device of equipment and base station.

35. method according to claim 23 is characterized in that the history by the mobile degree of one of them memory device of equipment and base station.

36. one kind by using at least one code division multiple access carrier wave, so that carry out the equipment of radio communication with the base station, described equipment comprises:

Transmitter, described transmitter uses first designated carrier, to base station first signal; And

CPU is used for effectively communicating by letter with transmitter, and described CPU comprises:

Determine operating conditions, described operating conditions comprises the cell moving degree;

Select first designated carrier according to determined operating conditions; And,

Use first designated carrier, set up wireless communication link with the base station.

37. equipment according to claim 36 is characterized in that first designated carrier is corresponding to one of them of Asynchronous Code Division Multiple Access communication link and synchronous code division multiple access communication chain.

38., it is characterized in that: also will select first designated carrier according to the quantity of available S-CDMA spreading code according to the described equipment of claim 37.

39., it is characterized in that according to the described equipment of claim 38: if the quantity of available S-CDMA spreading code less than predetermined quantity, then first designated carrier is corresponding to the Asynchronous Code Division Multiple Access link.

40. according to the described equipment of claim 37, it is characterized in that: CPU also uses the transmitter base station adjacent with another to communicate, and provides corresponding to another first designated carrier in Asynchronous Code Division Multiple Access communication link and the synchronous code division multiple access communication chain.

41. equipment according to claim 36 is characterized in that: CPU also:

Variation in the detecting operation situation;

First designated carrier of selecting to revise carries out wireless code division multiple access communication, and wherein, first designated carrier of described modification depends on the variation in the operating conditions; And

Use the first carrier of revising, set up wireless communication link with the base station.

42. according to the described equipment of claim 41, it is characterized in that: first designated carrier of described modification is corresponding to one of them of Asynchronous Code Division Multiple Access link and S-CDMA link.

43., it is characterized in that: select first designated carrier of described modification also to depend on the quantity of available S-CDMA spreading code according to the described equipment of claim 42.

44., it is characterized in that according to the described equipment of claim 43: if the quantity of available S-CDMA spreading code less than predetermined quantity, then first designated carrier of selected modification is corresponding to the Asynchronous Code Division Multiple Access link.

45. equipment according to claim 36 is characterized in that: also comprise receiver, described receiver uses second designated carrier, receives secondary signal from the base station, and wherein, receiver is effectively communicated by letter with CPU.

46. according to the described equipment of claim 45, it is characterized in that: the secondary signal that receives comprises the data corresponding with mobile degree, and wherein, CPU is also determined the mobile degree of equipment.

47. according to the described equipment of claim 45, it is characterized in that: the secondary signal that receives comprises the data corresponding with the speed of equipment, and wherein, CPU is determined the mobile degree of equipment also according to the speed of equipment.

48. the signal of communication in the wireless communication medium that is included between equipment and the base station, described wireless signal comprises a plurality of carrier waves, in a plurality of carrier waves each provides one of them of synchronous code division multiple access communication chain and Asynchronous Code Division Multiple Access communication link, wherein, each carrier wave provides the synchronous code division multiple access communication chain that is being used by fixing wireless device, and each carrier wave provides the Asynchronous Code Division Multiple Access communication link that is being used by the wireless device that moves.

49. according to the described signal of communication of claim 48, it is characterized in that: a plurality of carrier waves are set to the multi-carrier broadband signal.

50. according to the described signal of communication of claim 49, it is characterized in that: the bandwidth of multi-carrier broadband signal is at least 5MHz.

51. according to the described signal of communication of claim 48, it is characterized in that: wireless signal also comprises the mobile degree of equipment.

52. according to the described signal of communication of claim 51, it is characterized in that: mobile degree is corresponding to one in fixing or the mobile status.

53., it is characterized in that according to the described signal of communication of claim 52: if the speed of equipment less than predetermined amount, then mobile degree is fixed.

54. one kind is passed through to use at least one code division multiple access carrier wave, so that slave unit receives the base station of radio communication, described base station comprises:

CPU is used for effectively communicating by letter with transmitter described CPU:

Determine the operating conditions of equipment, described operating conditions comprises the cell moving degree;

Select first designated carrier according to the operating conditions of determining; And

Use first designated carrier, set up wireless communication link with equipment; And

Receiver, described receiver uses first designated carrier, receives first signal from described equipment.

55. according to the described base station of claim 54, it is characterized in that: first designated carrier is corresponding to one of them of Asynchronous Code Division Multiple Access communication link and synchronous code division multiple access communication chain.

56. according to the described base station of claim 55, it is characterized in that: the selection of first designated carrier also depends on the quantity of available S-CDMA spreading code.

57., it is characterized in that according to the described base station of claim 56: if the quantity of available S-CDMA spreading code less than predetermined quantity, then first designated carrier is corresponding to the Asynchronous Code Division Multiple Access link.

58., it is characterized in that according to the described base station of claim 53: CPU also:

Detect the variation of the operating conditions of described equipment;

Select first designated carrier of modification, so that carry out wireless code division multiple access communication, wherein, first designated carrier of modification depends on the variation in the operating conditions; And

Use the first carrier of revising, set up wireless communication link with described equipment.

59. according to the described base station of claim 58, it is characterized in that: first designated carrier of modification is corresponding to one of them of Asynchronous Code Division Multiple Access link and S-CDMA link.

60., it is characterized in that: the quantity that the selection of first designated carrier revised is also depended on available S-CDMA spreading code according to the described base station of claim 59.

61., it is characterized in that according to the described base station of claim 60: if the quantity of available S-CDMA spreading code less than predetermined quantity, then first designated carrier of selected modification is corresponding to the Asynchronous Code Division Multiple Access link.

62. according to the described base station of claim 54, it is characterized in that: receiver uses second designated carrier, receives secondary signal from described equipment.

63. according to the described base station of claim 62, it is characterized in that: the secondary signal that receives comprises the data corresponding with mobile degree, and wherein, CPU is determined the mobile degree of described equipment also according to the data of the secondary signal that receives.

64. according to the described base station of claim 62, it is characterized in that: the secondary signal that receives comprises the data corresponding with the speed of equipment, and wherein, CPU is also determined the mobile degree of equipment according to the speed of equipment.

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