MXPA97008267A - Method and apparatus for providing variable transmission speed data in a communication system using multiplexed stadist - Google Patents

Abstract

The present invention relates to a variable speed transmission system, wherein a variable transmission rate data packet generated by a variable rate data source (20) is modulated on the traffic channel by means of the modulator ( 309 of traffic channel, in case the capacity of the traffic channel is greater than or equal to the data transmission speed of the packet.The data packet of variable transmission speed is modulated on the traffic channel by means of the modulator ( 30) of the traffic channel and at least one overflow channel by the traffic channel modulator (32), in case the capacity of the traffic channel is lower than the said data transmission rate. discloses a receiver system for receiving variable transmission rate data, wherein a received packet of the variable transmission rate data is received on the ac If the traffic channel capacity is greater than or equal to a data rate of the packet and where a variable rate data packet is received over the traffic channel and at least one Overflow channel, in case the capacity of the traffic channel is less than the data transmission rate

Description

METHOD AND APPARATUS FOR PROVIDING VARIABLE TRANSMISSION SPEED DATA IN A SYSTEM OF COMMUNICATION OOE USES STATISTICAL MULTIPLEX BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to communications. More particularly, the present invention relates to a new and improved communication system, wherein a user transmits variable speed data in an assigned traffic channel, however when the user's transmission exceeds the capacity of the assigned traffic channel , the user is provided with a temporary use of an overflow channel for use in conjunction with the assigned traffic channel.

II. Description of Related Art The present invention relates to multiple users using a communication resource such as a satellite transponder. More specifically, it is related to the preparation of the most efficient allocation of the communications resource. The problem, in the context of a satellite transponder, is efficiently allocating portions of the transponder's fixed communications resource to a large number of transponders.

P1550 / 97MX users who seek to communicate digital information with each other at a variety of bit rates and work regimes. The use of code division multiple access modulation (CDMA) techniques is one of several techniques for facilitating communications, in which a large number of users of the system are present. Other techniques of multiple access communication systems are known in the art, such as time division multiple access (TDMA), frequency division multiple access (FDMA) and AM modulation schemes such as lateral band, individual, compacted in amplitude (ACSSB, for its acronym in English). However, the extended spectrum modulation technique of CDMA has significant advantage over these modulation techniques for multiple access communication systems. The use of CDMA techniques in a multiple access communication system is described in US Patent No. 4,901,307 entitled ^ EXTENDED SPECTRUM MULTI ACCESS COMMUNICATION SYSTEM USING SATELLITE OR TERRESTRIAL REPEDIDERS1, assigned to the assignee of the present invention and incorporated herein by reference. The use of CDMA techniques in a multiple access communication system is described P1550 / 97MX additionally in U.S. Patent No. 5,103,459, entitled "SYSTEM AND METHOD FOR GENERATING FORMS OF SIGNAL WAVES IN A CDMA CELLULAR TELEPHONE SYSTEM", assigned to the assignee of the present invention and incorporated herein by reference. The inherent nature of being a broadband signal offers a form of frequency diversity by extending the signal energy over an excessive bandwidth, therefore, the gradual and selective variation of the frequency affects only a small part of the bandwidth. band of the CDMA signal The diversity of space or route is obtained by providing multiple signal routes through simultaneous links from a mobile user through two or more cell sites. take advantage of the multi-path environment through extended spectrum processing, by allowing a signal to come up with different propagation delays e receive and process separately. Examples of the use of the diversity of routes are illustrated in copending US Patent No. 5,101,501 entitled "SOFT COMMAND, LOOSE IN A CDMA CELL PHONE SYSTEM" and in US Patent No. 5,109,390 entitled "RECEIVER OF DIVERSITY IN A CDMA 'CELLULAR TELEPHONE SYSTEM, both assigned to the transferee of the P1550 / 97 X present invention and incorporated herein by reference. An additional technique that can be used to increase the efficiency of the communication resource allocation is to allow resource users to provide data at varying speeds, using in this way only the minimum amount of communication resource to meet your service needs. An example of the variable rate data resource is a variable speed vocoder (voice encoder) which is detailed in the application of US Patent Serial No. 08 / 044,484 which is a request for continuation of the application of US Patent No. of Series 07 / 713,661, now abandoned, entitled "VARIABLE SPEED VOCODER", assigned to the assignee of the present invention and incorporated by reference herein Since speech inherently contains periods of silence, ie pauses, it can be reduced the amount of data required to represent these periods The variable speed voice coding takes advantage of this fact more effectively by reducing the data rate during these periods of silence In a variable speed vocoder of the type described in the application US Patent No. Serial No. 08 / 004,484 mentioned above, are coded to P1550 / 97MX full speed approximately 40% of the speech packets. In the vocoder described in the patent application, the coding rate is selected according to the energy of the packet. When the packet energy exceeds a full speed threshold, the speech is coded at full speed. In the American patent application Serial No. 08 / 288,413 entitled "METHOD AND APPARATUS FOR SELECTING A CODING SPEED IN A VARIABLE SPEED VOCODER", assigned to the assignee of the present invention and incorporated by reference herein, which describes a method for reducing the number of full-speed packets with a minimum of sacrificed quality A variable-speed speech coder provides full-speed speech data when the speaker is actively speaking, thus utilizing the full capacity of the speech. transmission packets.When a variable speed speech coder is providing speech data at a lower than maximum speed, there is excess capacity in the transmission packets.A method to transmit additional data in the transmission packets of a size fixed, where the source of the data for the data packets is providing the data at a variable speed, is described in detail in the application P1550 / 97MX US Patent No. Serial No. 08 / 171,146, copending which is a continuing application of US Patent Application Serial No. 07 / 822,164 filed now as abandoned entitled "METHOD AND APPARATUS FOR THE ORGANIZATION OF THE DATA FORMAT FOR THE TRANSMISSION1, assigned to the assignee of the present invention and incorporated by reference herein In the aforementioned patent application, a method and apparatus for combining data of different types from different sources in a data package for transmission is described.

SUMMARY OF THE INVENTION A communications resource is typically divided into communication channels. Typically, for simplicity, each of these channels has the same capacity. It is possible for a communication system to reassign channels to users for each packet to be transmitted. This would allow, theoretically, an efficient allocation of the communication resource in maximum form. However, this technique would result in an unacceptable complexity in the design resulting from the receiver and transmitter. In the present invention, an efficient method for transmitting and receiving speed data is described P1550 / 97MX variable. In the present invention, each user is provided with an assigned voice or data channel, also referred to as a traffic channel. In addition, each user is provided with selective access to a grouping of voice or data channels, referred to as overflow channels that are shared by all users of the communication resource. When the speed of a user transmission exceeds the capacity of the allocated traffic channel, the communication system determines whether an overflow channel is available for use by the user. If an overflow channel is available, it is temporarily assigned to the user for transmission. The methods presented in the example modalities describe the cases where a user uses at most the traffic channel, assigned and an individual overflow channel. However, the methods described herein are easily applicable to cases where a user may require more than one overflow channel in addition to the assigned traffic channel. The method of the present invention for the assignment of overflow channels to users is based on a concept referred to as statistical multiplexing. In the general case of statistical multiplexing, any overflow channel can be assigned P1550 / 97MX in the common grouping of overflow channels to any user. In an alternative strategy of allocation of overflow channels, each user is limited to the use of a subset of overflow channels. By reducing the number of possible overflow channels, the design of the receiver can be simplified. The overflow channel allocation information identifies a receiver which of the possible flow channels, if any, will carry the relevant information to that receiver for each packet. The present invention describes two kinds of techniques for conveying overflow channel allocation information to a receiver. In one method, the overflow channel assignment information is explicitly provided. In an explicit implementation of the overflow channel allocation, the overflow channel allocation information is conveyed to the receiver as part of the message packets that are transmitted over the traffic channel or alternatively in a separate channel used for signaling. The explicit information of the overflow channel assignment may correspond to the current packet or may correspond to an input packet. The benefit of sending the overflow channel information is probably to reduce the amount of buffer needed in the receiver. This is achieved P1550 / 97MX expenses of the additional buffer in the transmitter. The other method for providing the overflow channel allocation information is implicitly. In the implicit channel allocation techniques, the overflow channel allocation information is not provided as part of the message packets that are transmitted over the traffic channel, nor is the information provided in a separate channel. In an implicit implementation of the overflow channel assignment, the receiver tests all possible overflow channels and determines if any of the overflow channels contain the data for that use. This can be achieved by encoding the identification information of the receiver in the overflow packet or by the combination of the traffic packet and the corresponding overflow packet which is linked to another in a way that the receiver can detect. It is a further objective of the present invention to detail the design of balanced pre-allocation tables. The pre-allocation tables expose which overflow channels can be used for the transmission of information to these receivers. The idea behind balanced pre-allocation tables is to create the probability of finding an overflow channel available P1550 / 97MX for transmission to all the receivers themselves. It is another object of the present invention to describe a method for achieving pre-allocation consistent with a pre-allocation table. The post-assignment is the method to actually assign the overflow channels for the transmission. It is an advantage of the present invention that the methods of the present invention can be adapted to the needs of the user in terms of capacity and probability of impediment. Methods are described for determining the number of necessary overflow channels, required, given a maximum probability of blocking, acceptable and the probability that an overflow channel will require for the transmission of a particular packet.

BRIEF DESCRIPTION OF THE DRAWINGS The features, objects and advantages of the present invention will become more apparent from the detailed description set forth below, when taken in conjunction with the drawings, in which reference characters are consistently used throughout the description and wherein: Figure 1 is a diagram illustrating an exemplary implementation of the present invention in a satellite communication system; Figure 2 is a block diagram of the system P1550 / 97MX of transmission of the present invention; Figure 3a-3d is an illustration of the structures of the transmission package, exemplary of the example embodiment; Figures 4a-4e is an illustration of the redundancy in a transmission packet and the transmit power level of the packet; Figure 5 is a block diagram of a receiver system for the reception of data with the implicit assignment of the overflow channel, where the overflow data is coded together with the traffic data; Figure 6 is a block diagram of a receiver system for the reception of data with the explicit assignment of the overflow channel, where the overflow data is coded together with the traffic data; Figure 7 is a block diagram of a receiver system for data reception with the implicit assignment of the overflow channel, where the overflow data is encoded separately from the traffic data; and Figure 8 is a block diagram of a receiver system for receiving data with the explicit assignment of the overflow channel, where the P1550 / 97MX Overflow data is encoded separately from the traffic data.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES A multiple access communication resource is divided into channels. This division is usually called multiplexing, there are three specific types: frequency division multiplexing (FDM), for its acronym in English), multiplexed time division (TDM, for its acronym in English), and multiplexed code division (CDM, for its acronym in English). The basic unit of information transmitted and received in a communication system is referred to as a package. Referring now to the Figures, Figure 1 illustrates an example implementation of the present invention in a satellite communication system such as the low-orbit satellite system, Globalstar MR.

It should be understood, however, that the present invention can be used in a land based system such as where base stations are used to communicate with remote or remote stations. In Figure 1, the present invention is used for communication with downlink of information to a station or user terminal 6 far from the entrance 8 via satellites 4 and 6 which may be geosynchronous or orbit types P1550 / 97MX terrestrial low (LEO, for its acronym in English). It should be noted that although the example implementation illustrates the communication between two satellites and a user terminal, the present invention is equally applicable for communication from two separate beams of the same satellite and a user terminal. The user terminal 2 may be a mobile station such as a portable telephone or other communications device, portable or mobile or the user terminal 2 may be a fixed communication device such as a local, wireless or a local circuit terminal of communications, central such as a base station, cellular. Although only two satellites, a user terminal, an individual and an individual input are shown in Figure 1 for ease of illustration, a typical system may contain a plurality of all of these. In the exemplary embodiment, satellites 4 and 5 are non-regenerative transponders or repeaters that are typically of the type that simply amplify, change in frequency and retransmit the signal received from input 8. The present invention is equally applicable to cases where satellites 4 and 5 are regenerative repeaters that demodulate and reconstitute the signal before retransmission. In the exemplary embodiment, the signal transmitted by satellites 4 and 5 to terminal 2 of P1550 / 97MX user and the signal transmitted from the signal 8 to the satellites 4 and 6 are spread spectrum signals. The generation of extended spectrum communication signals is described in detail in US Patents Nos. 4,901,307 and 5,103,459, mentioned above. The input 8 serves as an interface from a communication network to the satellites 4 and 6, or directly to a ground, base station (a configuration not shown). Input 8 is typically a central communications center that receives data via a network (not shown) that includes public switched telephone networks (PSTNs) and networks designed specifically for the communications of the present invention. The input 8 can be connected to the network (not shown) by communications by wireline or by means of an air interface. In the example mode, the input 8 transmits variable speed data to the user terminal 6. An information of the variable speed data communication system, the speed of which varies with time. An implementation of an extended-spectrum, variable-speed communication system is described in the aforementioned US Patent No. 5,103,459. The example mode, as in P1550 / 97MX the system described in the North American Patent No. 5,103,459, the communication resource is divided into different channels in the code space, and where each of the channels has the same information transport capacity. The difference between the communication system of the present invention and the system described in US Patent No. 5,103,459, is that in the system described in US Patent No. 5,104,459, each channel is capable of transporting information at all possible speeds , while in the present invention, each channel can independently transport information in a subset of possibilities. In the example mode, the input 8 is communicated to the user terminal 6, to one of four different information data rates. It should be noted that the methods described herein are equally applicable to a variable speed communication system that provides any number of speeds. The data rates of the present invention are referred to as an eighth speed, a quarter of speed, half speed and full speed. The full speed transmits approximately twice the information per bit that the average speed, the average speed transmits approximately twice the P1550 / 97MX information per unit of time as a quarter of a speed and a quarter of speed transmits approximately twice the information per unit of time as an eighth of speed. The relationships between the information speeds are approximate due to the inclusion of the supplementary bits in a packet. In the exemplary embodiment, a traffic channel has adequate capacity to carry a data packet of all speeds, except the full speed that requires a traffic channel plus an overflow channel. The full-speed packets are divided into halves with a first mica transmitted on a traffic channel and a second half transmitted on an overflow channel. The present invention is easily applicable to cases where there are more or less than four speeds, or where the highest speed requires more than two channels. Also, it is envisaged that the communication system of the present invention will communicate both fixed speed data and variable speed data. In the communication of the fixed rate data, a channel or set of channels is assigned for the specific use by that user during the duration of the service that is provided. It is possible that the communication system can use all channels in the communication resource as a general grouping for all users. In that P1550 / 97MX type of system, no channel is assigned to a specific user, and before the transmission of each packet, the communication system would assign the complete communication resource for the transmission. Although this system can arguably result in an efficient allocation of the resource in its maximum form, it results in an unacceptable level of complexity in both the receivers and the transmitters. In the example mode, the channels are divided into traffic channels and overflow channels. The number of channels in each group can vary with the use of system, link parameters or other factors. The first group of channels is the group of traffic channels. Each user who is currently communicating in the communication system is assigned in a traffic channel or set of traffic channels, specifically for use during the duration of the service. The second group of channels is the group of overflow channels. This group of channels is shared by all users of the communication system. Overflow channels are assigned based on need and reassigned at regular intervals. In the example mode, the overflow channels are reassigned during each packet interval. A packet interval is the time interval between packet transmissions P1550 / 97MX Consecutive data. In a preferred embodiment, the overflow channels are allocated by considering all full speed packets to be transmitted in a given range of the packet. In an alternative mode, the overflow channels could be assigned individually on a request basis or in accordance with an established distribution order. Additionally, the set of channels available for use with a traffic channel may be different from the overflow channels that can be used with other traffic channels. In the example mode, the number of overflow channels available for any traffic channel is set, but this number can be assigned to vary over time according to factors similar to those listed above that influence the division of the total channels between those used as traffic channels and those used as overflow channels. Figure 2 illustrates the transmission system of the present invention. In the first example embodiment of the transmission system of the present invention, when a packet for transmission is a full speed packet, the traffic channel portion of the data packet and an overflow channel portion of the data packet. they are coded together and provided P1550 / 97MX implicitly the overflow channel assignment data. As previously described, in an implicit implementation of the overflow channel allocation, the channel assignment information is not transmitted to the receiver. Instead, the receiver demodulates and decodes the information in its assigned traffic channel and the information of all possible overflow channels and determines if some of the information provided in the overflow channels is a second portion of a packet sent on the channel of traffic. The input data for the transmission is provided to the variable rate data source 20 which encodes the input data. The variable speed data source can encode the data, so that it is stronger to transmission errors, or it can compress the data, so that the transmission of the data requires less of the communication resource for the transmission or some combination of the two. In the exemplary embodiment, the variable rate data source 20 provides data at four different speeds such as full speed, average speed, quarter speed and one eighth speed. As discussed above, the present invention is equally applicable to data sources that provide data at any number of speeds. In the modality of P1550 / 97MX For example, full speed information is provided at 8.6 kbps in 172-bit packets, medium speed information is provided at 4 kbps in 80-bit packets, quarter-speed information is provided at 1.7 kbps in packets of 34 bits, and information at one-eighth speed is provided at 800 bps in 16-bit packets. Table 1 below illustrates the numerology used in the exemplary embodiment of the present invention.

TABLE 1. NUMEROLOOIA OF EXAMPLE OF THE PRESENT INVENTION.

P1550 / 97MX The present invention is equally applicable to other numerology. The number of bits specified as the data rates differs from the information rates due to the inclusion of the supplementary bits in the packet. A detailed description of these additional bits is described hereinafter. The exemplary embodiment of the example speed data source 20 is a variable speed vocoder as described in the aforementioned US Patent Application No. 08 / 004,484. In this case, the input to the data source 20 is a packet of speech samples and the output from the data source 20 is a packet containing a compressed representation of the speech samples. In the example mode of a variable speed vocoder, the energy of a packet of speech samples is measured and compared to a predetermined set of threshold values that determine the coding rate. In general, if the speech sample pack contains active speech, then the packet is coded at full speed. U.S. Patent Application Serial No. 08 / 288,413, mentioned above, teaches methods for reducing the number of packets encoded at full speed with minimum P1550 / 97 X impact on the quality of perception. US Patent Application Serial No. 08 / 288,413 describes how to select packets that would otherwise be decoded at full speed and mark these packets to be encoded at a lower speed. The methods taught in the US Patent Application Serial No. 08 / 288,413 can be used in conjunction with the vocoder of the US Patent Application Serial No. 08 / 004,484 to reduce the number of packets encoded at full speed with an impact minimum in the quality of perception. The variable rate data source 20 encodes the input data and provides it at one of the predetermined speeds. In the example mode, a traffic channel is capable of transporting encrypted packets at or below the average speed. When a data packet is encoded by the variable rate data source 20 at full speed, then the packet size exceeds the capacity of a traffic channel, assigned and must be transmitted using both a traffic channel and an overflow channel. If the data packet provided by the variable rate data source 20 is a half-speed, quarter-speed pack or a P1550 / 97MX eighth of speed, then the variable rate data source 20 provides the packet directly to the format organizer 24. The format organizer 24 generates a set of redundant bits according to error correction and detection methods which are well known in the art. technique. In the example mode, the redundant bits are cyclic redundancy check (CRC) bits, the generation is detailed in the co-pending US patent application Serial No. 08 / 171,146, mentioned above. Figures 3a-3d illustrate the package structures of the example mode. Figure 3a illustrates the packet structure of a full speed packet consisting of 172 information symbols followed by 12 redundant symbols (F) and then by 8 tail symbols (T). Figure 3b illustrates the structure of a medium speed packet consisting of 80 information symbols followed by 8 redundant symbols and then by 8 tail symbols. Figure 3c illustrates the packet structure of a quarter-speed pack consisting of 34 information symbols followed by 6 redundant symbols and then by 8 tail symbols. Figure 3d illustrates the package structure of a package of a P1550 / 97MX eighth speed consisting of 16 information symbols followed by 8 tail symbols. In the exemplary embodiment, the tail symbols are a series of binary zeros used to clean the memory of the encoder 26 and to allow the packets to be decoded separately in the decoder in the receiving system. The format organizer 24 transfers the packet to the encoder 26 that encodes the packet into coded symbols. In the exemplary embodiment, the encoder 26 is a velocity average convolution encoder. In an example embodiment, the convolution encoder is implemented using a digital change recorder with feedback. The encoder 26 provides the encoded packet to the interleaver device 28. The interleaver device 28 rearranges the binary digits of the encoded packet according to a predetermined format of the interleaver device. In the exemplary embodiment, the interleaver device 26 is a block interleaver device. In a block interleaver device, the data is entered into columns and exits in rows, thereby increasing the diversity of the data. In addition, the implementation of the interleaver device 28 for the P1550 / 97MX present invention provides redundancy in the packets, such that each packet is of full capacity consisting of the same number of binary digits. The addition of redundancy is described later. With reference to Figures 4a-4e, the interleaver 28 interleaves the binary digits of the packet, then groups the reordered binary digits into symbols. The binary digits can be the symbols themselves or the binary digits that comprise the symbols. In the example mode, each power control group (P1-P32) consists of 24 binary digits. Figures 4a and 4b illustrate the packet format for a full speed packet. The packet is halved with the first half of the full speed packet illustrated in Figure 4a, transmitted in the traffic channel and the second half of the full speed packet illustrated in Figure 4b transmitted in the overflow channel. It is noted that in this present redundancy in no half of the packet, because the transmission of a full speed packet uses the full capacity of both the assigned traffic channel and the accompanying overflow channel. Figure 4c illustrates a packet of half-speed traffic. It is pointed out that because the transmission P1550 / 97MX of the half-speed packets uses the full capacity of the traffic channel, there is no repetition provided in the packet. Figure 4d illustrates a quarter-speed package, in which each symbol is provided twice. Figure 4e illustrates a one-eighth speed traffic packet, in which each symbol is provided four times, the ordering of the energy control groups in Figures 4d-4e provides the average, maximum separation between a control group of energy and its duplicate. In this way, potentially if an energy control group is lost in the transmission, the information can be retrieved by using the duplicate and vice versa. The ordering of the energy control groups in Figures 4a-4e is for example purposes and the present invention applies equally to all arrangements. The interleaved packet is provided by the interleaver device 28 to the modulator 30. The modulator 30 modulates the packet in order to provide the packet in the allocated traffic channel. In the exemplary embodiment, the modulator 30 is a code division multiple access modulator (CDMA) as described in detail in U.S. Patent Nos. 4,901,307 and 5,103,459. In the modality of P1550 / 97MX For example, each packet is extended by a Walsh sequence (Wn) that is unique to that traffic channel and that is orthogonal to all other Walsh sequences used by all other traffic channels and overflow channels. The extended packet is then covered using a pseudo-random (PN) noise sequence that provides greater separation in the code space. Each traffic channel and overflow channel is distinguished only by its Walsh sequence. There is a limited number of available, orthogonal sequences, so that the greater the number of available overflow channels, the smaller the available traffic channels. Reciprocally, the more channels of traffic are allocated, the lower the number of channels available for overflow. This illustrates how the capacity of the system is undone against the probability that a full speed frame will be blocked from transmission. By allowing the number of overflow channels to vary with the quality of the propagation and usage path, a maximum utility of the communication resource is allowed. In the implicit channel allocation system, this requires additional overload or signaling information in order to keep receivers far away from the number of possible overflow channels. Both in P1550 / 97MX Implicit systems as explicit channel allocation, this causes increased complexity in the transmission system and in particular increased complexity in the cell controller 40. The modulator 30 provides the modulated packet to the transmitter 36, which up-converts the sequence and amplifies the modulated packet, and provides it to the antenna 38 which broadcasts the signal. Because the receiver of the present invention can combine the received energy of the symbols provided in a redundant manner, it is not necessary to transmit packets containing repetition to the same energy as packets that do not contain repetition. In the example mode, the energy for the transmission of a packet amounts inversely with the amount of the repetition present in the packet. The transmitter 34 receives a speed signal (RATE) from the cell controller 40 and amplifies the signal according to the speed indicated by the speed signal. The relationship between the necessary transmission energy and the amount of repetition is illustrated in Figures 4a and 4e. Figures 4a and 4b illustrate the overflow and traffic packets required to carry a full speed data packet.

P1550 / 97 X A full speed pack requires the full capacity of both the overflow channel and the traffic channel, so that no repetition is provided in any packet and both the overflow packet and the traffic packet are transmitted at a maximum power level E of the package. Again, in Figure 4c, in a medium speed packet, there is no repetition, so that the packet is provided at an energy level E. In Figure 4d, in a quarter-speed packet, there is a repetition rate of two, so that the packet is provided at half the packet energy of the medium speed packet or E / 2. In Figure 4e, in a packet of one-eighth speed, there is a repetition rate of four, so that the packet is provided at a quarter of the power of the packet of the medium speed packet or E / 4. In the case of transmitting a full speed packet, the variable rate data source 20 provides the packet or packets to the selector 22 and sends a request signal (REQ) to the cell controller 40. The cell controller 40 determines whether an overflow channel is available and provides a speed indication signal (RATE) to the selector 22 that indicates whether an overflow channel is available.

P1550 / 97MX of the ? potential overflow channels. As previously described,? it can be the set of all possible channels not designated for use as channels without traffic, or? it can be a subset of those channels for use by the recipient to which the message is to be sent. When the packet speed provided by the variable speed data source 20 is at full speed, there are several modes of the variable speed data source 20 to provide the full speed packet. The first mode of the variable rate data source 20 generates the full speed packet, independent of the availability of an overflow channel. In the event that an overflow channel is not available, then the packet is not transmitted and a packet deletion is detected in the receiver. Because the packets are of short duration, a user will not be adversely affected by the occasional packet, left. In this case, a full speed packet is provided to the selector 22, which either provides the full speed packet to the format organizer 24 if a flow channel is available, or does not provide a packet if an overflow channel is not available. . P1550 / 97MX A second mode of the variable rate data source 20 provides both a full speed packet and a medium speed packet, simultaneously representative of the same input data (i.e., the input speech is coded at different speeds) . If an overflow channel is available, then the full speed packet is transmitted. If an overflow channel is not available, then the medium speed packet is transmitted. In this case, the variable rate data source 20 provides two separately coded packets to the selector 22. if an overflow channel is available, then the selector 22 provides the medium speed packet to the format organizer 24. If it is not an overflow channel is available, then the selector 22 provides the average rate packet to the format organizer 24. A third mode of the variable rate data source 20 encodes the data output by the variable data source 20 in such a way that that the data of the medium speed packet is in a subset of the full speed packet. This can be achieved in two alternative modalities. In the first implementation, the speed data source 20 P1550 / 97MX Variable can be designed to be optimized by the average speed quality with additional binary digits, added in the package in case an overflow channel is available. In an alternative embodiment, the variable rate data source 20 can be optimized for full speed speech quality with significantly less significant data that is left or truncated if an overflow channel is not available. In this third embodiment of the variable rate data source 20, the variable rate data source 20 provides a full speed packet to the selector 22. If an overflow channel is available, then the selector 22 provides the full speed packet. complete the format organizer 24. If an overflow channel is not available, then the selector 22 provides only a predetermined subset of the full rate packet to the format organizer 24. In the cases described above, if an overflow channel is not available , then the selector 22 provides a packet at half speed or less and the transmission of the packet proceeds as described above. If an overflow channel is available, then the cell controller 40 provides a signal P1550 / 97MX from RATE to selector 22 indicating that an overflow channel is available, and selector 22 provides the full speed packet to the format organizer 24. In the example mode, the format organizer 24 organizes the packet formats as illustrated in Figure 3a by adding 12 redundant bits and 8 tail bits to the output packet. The format organizer 24 transfers its packet to the encoder 26. The encoder 26 encodes the packet as described above and provides the encoded packet to the interleaver 28. The interleaver 28 can operate in one of two ways. Either you can reorder the entire package as a unit or you can split the package into halves and reorder each independent half. In any case, the interleaver device 28 provides a first half of the packet interleaved to the modulator 30 for transmission over the allocated traffic channel and provides a second half to the modulator 32 for transmission over the assigned overflow channel. As described above, the modulator 30 modulates the packet to provide the packet in the allocated traffic channel. The modulator 32 modulates the second half of the packet provided by the interleaver device 28 to be provided in the assigned overflow channel. P1550 / 97MX The modulator 32 modulates the packet according to the CHANNEL ALLOCATION signal from the cell controller 40 which indicates the identity of the assigned overflow channel. In the example mode, the modulator 32 extends the packet by a unique sequence of Walsh (Wj), which is determined according to the CHANNEL ALLOCATION signal. The Walsh sequence (Wj) is unique for transmissions in the selected overflow channel, ensuring that the signal will be orthogonal to all other transmitted signals. As previously described, the extended signal is then again extended by a pseudorandom noise sequence. The modulators 30 and 32 provide modulated packets to the transmitter 34, which up-converts and amplifies the modulated packets and provides them to the antenna 36, which broadcasts the signal. In this case, because there is no repetition, the packet is transmitted with packet power E as shown in Figures 4a and 4b. Referring now to Figure 5, the signal diffusion by the antenna 36 of Figure 2 is received at the user terminal by the antenna 50 and is provided to the receiver (RCVR) 52. The receiver 52 downconverts and amplifies the received signal and provides the received signal to at least one circuit of P1550 / 97MX demodulation or "" index "of a RAKE receiver, such that this design should be used.Each index is comprised of a traffic demodulator 54 and the overflow demodulators 55a-55. It should be noted that? is the number of channels of overflow that could possibly be used in conjunction with the traffic channel in question, it is noted that it can be the total number of potential overflow channels or it can be a predetermined subset of potential overflow channels. 54 traffic and demodulators 55a-55? Of overflow are CDMA demodulators as described in US Patents Nos. 4,901,307 and 5,103,459, mentioned above, Traffic Demodulator 54 and Overflow Demodulators 55a-55? Are manipulative demodulators. by binary phase change (BPSK) The traffic demodulators 54 de-spread the received signal and additionally recover the s traffic data when de-extending the assigned Walsh sequence. The overflow demodulators also de-spread the received signal and additionally receive the overflow data upon de-spreading by a respectively assigned Walsh sequence of the various Walsh sequences assigned to the overflow channels. The traffic demodulator 54 demodulates the P1550 / 97MX received packet according to the assigned traffic channel and provides the demodulated packet to the buffer 56. The buffer 56 temporarily stores the demodulated traffic packet and provides the packet according to a predetermined synchronization sequence. Also, the received signal is provided to the? 55a-55v overdrive demodulators. The demodulators 55a-55? of overflow each demodulate the received signal according to a different channel of overflow. Each of the demodulators 55a-55? Overflow provides a demodulated packet, separated to the buffer 56. The buffer 56 temporarily stores the demodulated overflow packets and provides the packets according to a predetermined synchronization sequence. The buffer 56 provides the demodulated packets of the interleaver device 57 in such a way that all possible transmission scenarios can be tested. In the example mode, transmission scenarios are tested in the following order: one-eighth speed, one quarter speed, half speed, full speed using overflow channel 1 to transport the second half of the packet, full speed using the Overflow channel 2 for P1550 / 97MX transport the second half of the package, ..., full speed using the channel? overflow to transport the second half of the package. In the exemplary embodiment, the buffer 56 first provides the demodulated traffic packet to the interleaver device 57, which reorders the data according to a one-eighth speed sort format. The deinterleaver device 57 provides the reordered packet to the decoder 58, which decodes the packet and assigns to the decoded packet a value indicating the probability of the packet transmitted was a one-eighth speed packet. In the exemplary embodiment, the decoder 58 is a Viterbi decoder of containment length 7. Viterbi decoders of this type are described in detail in the aforementioned US Patent Application Serial No. 08 / 023,789. Then, the buffer 56 provides the demodulated traffic packet to the de-interleaver device 57 which reorders the data according to a quarter-rate sort format. The deinterleaver device 57 provides the reordered packet to the decoder 58, which decodes the packet and assigns to the decoded packet a value indicating the probability that the transmitted packet was a packet of P1550 / 97MX a quarter of speed. Then, the buffer 56 provides the traffic packet, demodulated to the de-interleaver device 57 which reorders the data according to a half-rate ordering format. The de-interleaver device 57 provides the reordered packet to the decoder 58, which decodes the packet and assigns to the decoded packet a value indicating the probability that the transmitted packet was a half-speed packet. Then, the buffer 56 provides the traffic packet, demodulated, concatenated with the overflow packet, demodulated from the overflow demodulator 1, the block 55a, to the interleaver device 57 which reorders the data according to a format of full speed ordering. The deinterleaver device 57 provides the reordered packet to the decoder 58, which decodes the packet and assigns to the decoded packet a value indicating the probability of the packet transmitted was a full speed packet with the second half of the packet transmitted on the channel 1 of overflow Then, buffer 56 then provides the demodulated traffic packet, concatenated with the overflow packet, demodulated from the demodulator P1550 / 97MX 2 overflow, block 55b, to the interleaver device 57 which reorders the data according to a full speed sort format. The deinterleaver device 57 provides the reordered packet to decoder 58, which decodes the packet and assigns to the decoded packet a value indicating the probability that the transmitted packet was a full speed packet with the second half of the packet transmitted on channel 2. of overflow. The process is repeated for each of the? possible overflow channels. At the end of the process, all decoded packets are provided to the diversity combiner element 60, which together with estimates of decoded packets from other propagation routes demodulated by other indices, combine to provide an improved estimate of the transmitted packet. The design of the diversity combining elements is described in detail in the aforementioned US Patent Application Serial No. 07 / 432,552. In the second example embodiment of the transmission system of the present invention, the traffic portions of the data packet and the overflow portions of the data packet are coded together and the overflow channel allocation data is provided explicitly. In an explicit implementation of P1550 / 97MX Overflow channel assignment, channel assignment information is transmitted with traffic data. The explicit allocation of the overflow channel greatly reduces the decoding operation in the receiver, because the receiver knows in which overflow channel, the overflow data will be provided. The explicit allocation of the overflow channel reduces the amount of information that can be provided in the traffic channel. With reference back to Figure 2, the input data for the transmission is provided to the variable rate data source 20. The variable rate data source 20 provides the data at four different speeds. If the transmission speed of the packet is less than complete, the transmission system operates identically to the transmission system of the first example mode. When the variable rate data source 20 provides a full speed packet to the selector 22, it provides a request signal corresponding to the cell controller 40. If an overflow channel is not available, then the selector 22 provides a packet at half speed or less and the transmission of the packet proceeds as previously described. If an overflow channel is available, P1550 / 97MX then the cell controller 40 provides an RATE signal (speed) to the selector 22 which indicates that an overflow channel is available, and the selector 22 provides the full speed packet to the format organizer 24. The cell controller 40, also provides a channel assignment signal to the format organizer 24. The channel assignment signal consists of b binary symbols, where b is the smallest integer such that: b > log2 ?, (1) where ? is the number of possible overflow channels to carry the second part of the full speed data packet. In the example mode, the format organizer 24 formats or organizes the package in a format as illustrated in Figure 3a. The explicit channel assignment data can replace any portion of the packet. In a preferred embodiment, the channel allocation bits replace a fraction of the tail bits in the packet. In another preferred embodiment, the channel allocation bits are provided in the far left portion of the packet, because this part of the packet is first decoded P1550 / 97 X by the receiver. The format organizer 24 transfers its packet to the encoder 26. The encoder 26 encodes the packet as described above and provides the encoded packet to the interleaver device 28. In the second example embodiment, the interleaver device 28 interleaves the traffic channel portion. of the full speed channel, separately from the overflow channel portion to the full speed package. The interleaved traffic channel packet is provided to the modulator 30 and the interleaved channel packet is interleaved to the modulator 32. As described above, the modulator 30 modulates the traffic channel packet to provide the packet on the channel of assigned traffic. The modulator 32 modulates the overflow channel packet provided by the interleaver device 28 to be provided in the assigned overflow channel. As described above, the modulator 32 modulates the packet according to the CHANNEL ALLOCATION signal from the cell controller 40 which indicates the identity of the assigned overflow channel. The modulators 30 and 32 provide the modulated packet to the transmitter 36, which upconverts and amplifies the modulated packet and provides it to the antenna P1550 / 97MX 38, which broadcasts the signal. In this case, because there is no repetition, the packet will be transmitted to packet power level E as shown in Figures 4a and 4b. Referring now to Figure 6, the signal diffusion by the antenna 36 of Figure 2 is received by the antenna 70 and is provided to the receiver (RCVR) 72. The receiver 72 downconverts and amplifies the received signal and provides the received signal to the traffic demodulator 74 and to the buffer 76. The reception of the packets that are of a speed lower than the full speed proceeds as previously described. In the exemplary embodiment, the traffic demodulator 74 and the overflow demodulator 78 are code division multiple access demodulators (CDMA) as described in U.S. Patent Nos. 4,901,307 and 5,103,459, mentioned above. Again, in the exemplary embodiment, the traffic demodulator 74 and the overflow demodulator 78 are binary phase change manipulation demodulators (BPSK). Upon reception of the full-speed packets, the traffic demodulator 74 demodulates the received packet according to the assigned traffic channel and provides the demodulated packet to the de-interleaver device 80. The P1550 / 97MX interleaver 80 reorders the binary symbols of the traffic channel packet and provides the reordered packet to the decoder 82. The decoder 82 decodes the packet. Again in the example mode, the decoder 58 is a Viterbi decoder. The Viterbi decoders are described in detail in the aforementioned US Patent Application Serial No. 08 / 023,789. The decoder 82 provides a channel assignment signal to the overflow demodulator 78. The decoder can decode the complete traffic channel packet before providing the overflow channel allocation data to the overflow demodulator 78. However, in a preferred embodiment, the channel allocation data is provided in the leftmost portion of the packet, such that it is the first data decoded by the decoder 82. This reduces the required size of the buffer 76 and allows decoding fastest of the full full speed package. After the decoder 82 provides the channel assignment signal to the overflow demodulator 78, the decoder 82 provides a synchronization signal to the buffer 76. The buffer 76, in response to the synchronization signal, P1550 / 97MX provides the received packet to the overflow demodulator 78. The overflow demodulator 78 demodulates the received packet according to the channel assignment signal and provides the demodulated packet to the interleaver 80. The de-interleaver 80 as described previously, rearranges the data in the demodulated overflow packet and provides the packet reordered to the decoder 82. The decoder 82 decodes the overflow portion of the packet. The decoder 82 concatenates the decoded traffic channel packet with the decoded overflow channel packet and provides the result to the diversity combining element 84. The combiner element 84 receives the decoded packet estimate from the decoder 82 and the packet estimates from decoded estimates of other indices. The combiner 84 operates, as described by considering the combiner element 60, to provide an improved estimate of the packet. In the third example embodiment of the transmission system of the present invention, the traffic portions of the data packet and the overflow portions of the data packet are coded together and the overflow channel allocation data is explicitly provided. In the third example mode, the channel allocation data explicitly P1550 / 97MX provided are related to the new data packet as opposed to the current packet as described in the second embodiment. The proportion of the channel allocation data in advance reduces the necessary complexity of the accompanying receiver system. Referring back again to Figure 2, the input data for the transmission is provided to the variable rate data source 20. The variable rate data source 20 encodes the current packet data and determines the coding rate for the next data packet. If the speed of the next data packet is full speed, the variable rate data source 20 sends a request signal (REQ) to the cell controller 40. In response to the request signal, the cell controller 40 determines whether an overflow channel is available for the transmission of the next data packet. If an overflow channel is available for transmission of the next data packet, the cell controller 40 provides a channel allocation signal of the next packet (NFCA) to the format organizer 24. The selector 22 provides the current packet as described previously to the format organizer 24. The format organizer 24 combines the channel assignment information of the next packet with the data of P1550 / 97MX information, redundant data and queue bits, and provides the packet to the encoder 26. Because the channel allocation data is provided in advance, it is not necessary to provide the channel allocation data in the far left portion. of the package. The encoder 26 encodes the packet as previously described and provides the encoded packet to the interleaver 28. The interleaver 28 rearranges the binary symbols of the current packet. If the current packet is a full speed packet, then the packet can be interleaved as an individual unit as described in the first example embodiment, the packet can be interleaved in two separate halves as described in the second example embodiment. If the current packet is less than the full speed, it is provided by the interleaver device 28 to the modulator 30. The interleaved packet is modulated according to the traffic channel in which the packet is to be transmitted and then is provided to the transmitter 34, where the packet is upconverted and amplified and then broadcast via the antenna 36. If the current packet is full speed, it is provided by the interleaver 28 to the modulators 30 and 32. The interleaved packet is P1550 / 97MX modulates by the modulator 30 to be provided in the traffic channel and by the modulator 32 to be provided in the assigned overflow channel. The packet is then provided by the modulators 30 and 32 to the transmitter 34, where it is upconverted and amplified and then broadcast by the antenna 36. In an improved mode, the cell controller 40 determines whether an overflow channel is available for transmission of the subsequent frame and if there is not, the cell controller 40 sends a message to the variable rate data source (20) that recodes the subsequent frame at a rate that can be transmitted without the use of an overflow channel. Referring now again to Figure 6, the signal diffusion by the antenna 36 of Figure 2 is received by the antenna 70 and is provided to the receiver (RCVR) 72. The receiver 72 downconverts and amplifies the received signal and provides the received signal to the traffic demodulator 74 and as illustrated in the dotted line, directly to the overflow demodulator 78.

In this implementation, the buffer 76 is not used. The traffic demodulator 74 demodulates the received packet according to the allocated traffic channel and provides the demodulated packet to the interleaver device 80. If the packet received P1550 / 97MX previously contained channel assignment information for the current packet, then this information is provided by the buffer 83 to the overflow demodulator 78. The overflow demodulator 78 demodulates the received signal according to the overflow channel assignment information, provided in the previous packet. The traffic demodulator 74 provides the demodulated traffic portion of the packet transmitted to the interleaver device 80. The interleaver device 80 reorders the packet according to a predetermined de-interleaving format and provides the reordered packet to the decoder 82. The decoder 82 decodes the packet. If channel assignment data exists for the next packet present in the decoded packet. Then the decoder 82 provides the channel allocation data for the next packet to the buffer 83. The decoder 82 also provides the decoded packet to the combiner element 84 which combines the decoded estimate of the decoder 82 with the decoded estimates of other indices to provide a decoded, improved estimate. In the fourth example embodiment of the transmission system of the present invention, the portions of P1550 / 97MX data packet traffic and the overflow portions of the data packet are encoded separately and implicitly provided in the overflow channel allocation data. With reference again back to the Figure 2, the input data for the transmission is provided to the variable rate data source 20. If the data packet provided by the variable rate data source 20 is an average speed, quarter speed or eighth speed packet, then the transmission system operates as described in the first example embodiment. If the packet is a full speed packet, then the variable rate data source 20 sends a request signal to the cell controller 40 and provides the packet to the selector 22. The cell controller 40, in response to the request signal of the variable speed data source 20, provides a speed signal to the selector 22. If the speed signal indicates that there is no overflow channel available, then the selector 22 provides a lower speed packet as previously described, and the transmission proceeds as described in the first example mode. If the speed signal indicates that there is an overflow channel available, then the selector 22 P1550 / 97MX provides the full speed packet to the format organizer 24. The format organizer 24 adds the redundant bits and the tail bits as described in the first example mode. The formatted packet is then provided to the encoder 26. The encoder 26 encodes the packet as two separate halves, which results in two packets encoded separately. The encoder 26 provides two encoded packets to the interleaver 28. The interleaver 28 rearranges the binary symbols of the two encoded packets separately. The interleaver device 28 provides a first packet interleaved with the modulator 30 and a second packet interleaved with the modulator 32. As described above, the modulator 30 modulates the packet to provide the first packet interleaved in the allocated traffic channel. The modulator 32 modulates the second interleaved packet provided by the interleaver device 28 to be provided in the assigned overflow channel. The modulator 32 modulates the packet according to the CHANNEL ALLOCATION signal of the cell controller 40 which indicates the identity of the assigned overflow channel. Modulators 30 and 32 provide the package P1550 / 97MX modulated to transmitter 36, which upconverts and amplifies the modulated packet and provides it to antenna 38, which broadcasts the signal. In this case, because there is no repetition, the packet will be transmitted to packet power level E as shown in Figures 4a and 4b. Referring now to Figure 7, the signal diffusion by the antenna 36 of Figure 2 is received by the antenna 90 and is provided to the receiver (RCVR) 92. The receiver 92 downconverts and amplifies the received signal and provides the received signal to the traffic demodulator 94 and the demodulators 96a-96? overflow of a first index and other indices if a RAKE receiver design is used. Again ? is the number of possible overflow channels for the receiving system. This can be the set of all unused channels or a designated subset. In the exemplary embodiment, the traffic demodulator 54 and the overflow demodulators 55a-55v are CDMA demodulators as described in U.S. Patent Nos. 4,901,307 and 5,103,459, mentioned above. In the exemplary embodiment, the traffic demodulators 54 and the demodulators 55a-55? Overflows are binary phase change manipulator (BPSK) demodulators. The traffic demodulator 54 demodulates the signal P1550 / 97MX received in accordance with the demodulation format of the allocated traffic channel and provides the demodulated packet to the traffic de-interleaver device 98. The received signal is also provided to the? demodulators 96a-96? of overflow. The overflow demodulators 96a-96b each demodulate the received signal according to a hypothetical, different overflow channel demodulation format. The demodulators 96a-96? Do they provide a demodulated package to the de-interleaver devices lOOa-lOO? of overflow, respectively. The deinterleaver 98 traffic device and the interleaver devices lOOa-lOO? of overflows reorder the binary symbols in the demodulated packets and provide the reordered packets to the traffic decoder 101 and the decoders 99a-99? of overflow, respectively. The traffic decoder 101 and the decoders 99a-99? of overflow decode the reordered packets and provide them to the combiner 102. The combiner 102 determines whether any of the decoded packets of the decoders 99a-99? overflows are the second halves of the decoded traffic packets, when checking the redundant bits, to determine if there is a match between the decoded overflow packet and the traffic packet P1550 / 97MX decoded If the combiner 102 determines that any of the decoded packets of the decoders 99a-99? of overflow are the second halves of the decoded traffic packet, then the combiner 102 concatenates the decoded overflow packet to the decoded traffic packet. The combiner 102 combines the decoded packet with the estimates of the decoded packet of other indices as previously described, to provide an improved estimate of the packet. In the fifth example embodiment of the transmission system of the present invention, the traffic portions of the data packet and the overflow portions of the data packet are encoded separately and the overflow channel allocation data is explicitly provided for the current package. Referring again to Figure 2, the input data for the transmission is provided to the variable rate data source 20. In the transmission of packets that are less than full speed, transmission continues as described above. Again, the variable rate data source 20 provides data at four different speeds. If the transmission speed of the packet is one speed lower than the full speed, the P1550 / 97MX The transmission system operates identically to the transmission system of the first example mode. Where the variable rate data source 20 provides a full speed packet to the selector 22, it provides a request signal corresponding to the cell controller 40. If an overflow channel is not available, then the selector 22 provides a packet at half speed or less and the transmission of the packet proceeds as described above. If an overflow channel is available, then the cell controller 40 provides an RATE signal to the selector 22 indicating that an overflow channel is available, and the selector 22 provides the full speed packet to the format organizer 24. The controller Cell 40 also provides a channel allocation signal to the format organizer 24. As described above, the channel assignment signal consists of b binary symbols, where b is determined by the formula: b = log2 > , (2) where ? is a number of possible overflow channels for transporting the second part of the full speed data packet. P1550 / 97MX The full rate packet and the channel assignment data are provided to the format organizer 24. In a preferred embodiment, the packet is formatted as described in the second example mode, with the channel assignment data placed in the packet. to be in the first portion of the decoded packet in a receiver. The formatted packet is provided to the encoder 26. The encoder 26 encodes the full speed packet into two separate halves. The first encoded packet and the second encoded packet are provided to modulators 30 and 32, respectively. The modulator 30 modulates the first packet encoded according to the assigned traffic channel modulation format and the modulator 32 modulates the second packet encoded according to the assigned overflow channel modulation format. The modulated packets are provided to the transmitter 34 that upconverts and amplifies the modulated packets as described above. The signal is provided by the transmitter 34 to the antenna 36 and is broadcast to the receiver systems. With reference to time to Figure 8, the signal diffusion by the antenna 36 of Figure 2 is received by the antenna 110 and is provided to the receiver (RCVR) 112. The receiver 112 downconverts and amplifies the P1550 / 97MX received signal and provides the received signal to the traffic demodulator 114 and the buffer 116. The reception of the packets that are of a speed lower than the full speed proceeds as previously described. In the example mode, the traffic demodulator 114 and the overflow demodulator 120 are code division multiple access demodulators (CDMA) as described in US Patent Nos. 4,901,307 and 5,103,459, mentioned above. Again, in the exemplary embodiment, the traffic demodulator 114 and the overflow demodulator 120 are demodulators by binary phase change manipulation (BPSK). Upon reception of the full-speed packets, the traffic demodulator 114 demodulates the received packet according to the allocated traffic channel demodulation format and provides the demodulated packet to the traffic de-interleaver 118. The interleaver device 118 which sorts the binary symbols of the traffic channel packet and provides the reordered packet to the traffic decoder 122. The traffic decoder 122 decodes the packet. Again, in the exemplary mode, the traffic decoder 122 and the overflow decoder 126 are P1550 / 97MX Viterbi decoders of length 7 containment. The Viterbi decoders are described in detail in the aforementioned US Patent Application Serial No. 08 / 023,789. The decoder 122 provides the channel assignment information to the overflow demodulator 120 and provides the decoded traffic packet to the combining element. The decoder can decode the complete traffic channel packet before providing the overflow channel allocation data to the overflow demodulator 120. However, in a preferred embodiment, the channel assignment data is provided at the source of the packet such that it is the first data decoded by the decoder 122. This reduces the required size of the buffer 116 and allows faster decoding of the data. package. After the decoder 122 provides the channel assignment signal to the overflow demodulator 120, the decoder 122 provides a synchronization signal to the buffer 116. The buffer 116, in response to the synchronization signal, provides the received packet to the overflow demodulator 120. The overflow demodulator 120 demodulates the received packet according to the overflow channel demodulation format, allocated and provides the packet P1550 / 97MX demodulated to the overflow dis-interleaver device 124. The de-interleaver device 124 as described previously reorders the data in the demodulated envelope envelope and provides the reordered packet to the overflow decoder 126. The overflow decoder 126 decodes the overflow portion of the packet and provides the decoded overflow packet to the combiner 128. The combiner 128 combines the decoded overflow packet with the decoded traffic packet, to provide the full speed packet estimate. The combiner 128 also serves to combine the estimates of the package of other indices as previously described. In the sixth example embodiment of the transmission system of the present invention, the traffic portions of the data packet and the overflow portions of the data packet are encoded separately and the overflow channel allocation data is explicitly provided for the next channel. Referring again to Figure 2, the input data for the transmission is provided to the variable rate data source 20. The variable rate data source 20 encodes the current packet and determines the coding rate of the next packet.

P1550 / 97MX If the coding rate for the next packet is full speed, the variable rate data source 20 sends a request signal to the cell controller 40. If an overflow channel is available, for the transmission of the next data packet then, the cell controller 40 provides an RATE signal to the selector 22 indicating that an overflow channel is available, and the selector 22 provides the speed packet. complete the format organizer 24. The cell controller 40 also provides a channel assignment signal to the format organizer 24. The full rate packet and the channel assignment data are provided to the format organizer 24. The packet is formatted as described in the third example embodiment with the channel assignment data for the next data placed in the packet. The formatted packet is provided to the encoder 26. The encoder 26 encodes the full speed packet into two separate halves. The first encoded packet and the second encoded packet are provided to the interleaver 28 which reorders the binary symbols in the packet separately. The interleaver device 28 provides the reordered packets to the modulators 30 and 32, respectively. Modulator 30 modulates the first coded packet of agreement P1550 / 97MX with the assigned traffic channel modulation format and the modulator 32 modulates the second modified packet according to the channel modulation format of the assigned overflow. The modulated packets are provided to the transmitter 34 that upconverts and amplifies the modulated packets as described above. The signal is provided by the transmitter 34 to the antenna 36 and is broadcast to the receiving systems. Referring now to Figure 8, the signal diffusion by the antenna 36 of Figure 2 is received by the antenna 110 and is provided to the receiver (RCVR) 112. The receiver 112 downconverts and amplifies the received signal and provides the signal received to the traffic demodulator 114 and to the overflow demodulator 120. The traffic demodulator 114 demodulates the received packet according to the allocated traffic channel demodulation format and provides the demodulated packet to the traffic interleaver 118. The traffic interleaver 118 reorders the binary symbols of the packet and provides them to the traffic decoder 122. The traffic decoder 122 decodes the packet and if there is channel assignment data in the packet for the next packet then these data are provided to the buffer 117.

P1550 / 97MX The traffic decoder 122 provides the decoded packet to the combiner 128. If the previously received packet contained the channel assignment information for the current packet, then this information is provided by the buffer 117 to the overflow demodulator 120. The overflow demodulator 120 demodulates the overflow portion of the packet according to the channel allocation information provided by the previous packet. The traffic demodulator 114 provides the demodulated traffic portion and the transmitted packet to the traffic de-interleaver device 118 where the traffic portion of the packet is rearranged according to a traffic channel de-interleaving format. The reordered packet is provided to the traffic decoder 122 which decodes the traffic channel portion of the packet and provides it to the combining element 128. If the packet is full speed, then the overflow demodulator 120 provides the demodulated overflow portion of the packet transmitted to the overflow interleaver device 124. The overflow interleaver device 124 reorders the binary symbols of the overflow packet and provides the reordered overflow packet to the overflow decoder 126. The decoder 126 decodes the packet P1550 / 97MX of overflow and provides the decoded overflow packet to the combiner 128. The combiner 128 combines the decoded traffic packet with the decoded overflow packet. In addition, the combiner 128 combines the estimate of the packet with the packet estimates of other indices as previously described to provide an improved estimate of the packet that is provided to the user of the receiving system. The next part of the present invention to be described are various methods of assigning the overflow channels. This assignment operation is performed by the cell controller 40. The allocation of a group of channels to call can be provided in a variety of ways. The simplest that is the random selection from the grouping. A more sophisticated technique follows the design of the experimental method known as statistical multiplexing. In a typical case, any channel in a common pool can be triggered to any call on an assignment basis per request. As described above, this general strategy leads to systems and receivers that are unnecessarily complex. The present invention describes new allocation strategies that minimize the complexity of the complete communication system. As indicated above, the approach of P1550 / 97MX The usual assignment is to assume that any of the channels in the overflow pool can be assigned to any call. This allocation strategy allows the maximum number of calls to be assigned to the overflow channels. However, it also requires the more complex receiver since the receiver must be prepared to receive information on a traffic channel and any of the overflow channels. If the number of overflow channels is allowed to vary, recipients must deal with this additional complexity. In an alternative scheme, called pre-assignment, a predetermined subset of overflow channels is pre-assigned to each user at the beginning of the call. Then, when the time comes to post-assign an overflow channel to that call, the assigned overflow channel is chosen from this subset. A simpler receiver can then be used, because it needs to be able to demodulate the information in a limited set of channels. Hybrid schemes are provided, by means of which a main pool of overflow channels is available for all calls, but where a secondary pool of overflow channels is pre-assigned to each call in the event that a channel is not available. overflow of the main grouping. P1550 / 97MX The following are objectives and advantages of the allocation methods of the present invention. 1. The design of balanced pre-allocation tables. 2. An algorithm to achieve post-allocation consistent with a pre-allocation table. 3. Determination of an optimal allocation strategy based on the probability of impediment of several schemes. As described above, when an individual channel does not have the information that carries the capacity to accommodate a packet, two or more channels can be used to carry that packet. In the preferred embodiment, an individual traffic channel is sufficient to carry a packet most of the time, but occasionally two or more overflow channels are required to aid in the transport of the packet. A call is a sequence of packets. As previously described, when a call is established, the single use of an individual traffic channel is allocated, but when two or more channels are required to transport a packet in the call, temporary use of additional overflow channels is given. This scheme is referred to in the present invention as statistical multiplexing. As described above, there are two sets P1550 / 97MX of channels: a set of traffic channels and a set of overflow channels. When a call is established, one of the traffic channels is permanently assigned for the transmission of the packets on that call. In the occasional circumstance that a packet in the call requires two or more channels, the packet is transported in the assigned traffic channel and one or more of the overflow channels that are temporarily assigned to that user. If another packet in the call requires two or more channels, the same traffic channel is used, but a different overflow channel may be used to transport the second part of this packet. When a single traffic channel carries a packet, the traffic channel is active. When a packet requires two channels (one traffic channel and one overflow channel), the assigned traffic channel is superactive. They can be permanently assigned to so-called overflow channels (or equivalently to active traffic channels). However, where a traffic channel becomes super-active infrequently, this solution is a waste of capacity. For example, even in the case where only one overflow channel is required to accommodate a superactive traffic channel, this scheme would result in half of the P1550 / 97MX channels are assigned as overflow channels. Yet, at any moment of time, most of these overflow channels would be unoccupied. Instead, in the present invention describes methods by which the set of traffic channels share a relatively small number of overflow channels. The following invention describes methods to achieve this purpose. An application of this invention is to the downlink path of the low-orbit satellite communication system, Globalstar, that is, the route from the satellite to the mobile receivers. N denotes the total number of channels (traffic overflow) in the communications resource. In the example mode, N equals 128. The sample modes present the specific case where N channels are divided into two fixed size groups consisting of n overflow channels and (Nn) traffic channels, although the ideas are easily applicable to cases where the size of the groups can be varied with the load, quality of the route, or any other factor. At any moment of time, only b of the (N-n) traffic channels are active. In addition, only a small fraction of the active b channels are superactive. In the example mode, it is assumed that a P1550 / 97MX Superactive traffic channel requires only one overflow channel. It should be understood, however, that the ideas discussed are generalized to the case where a package requires two or more channels of overflow. In the example mode, there is a previous assignment (or pre-allocation) of the overflow channels to the active traffic channels. The allocation is such that each overflow channel is assigned to many active traffic channels but exactly k, (k <n), overflow channels are assigned to each active traffic channel. When an active traffic channel becomes superactive, a portion of the packet is transported by that traffic channel also being transported by one of the k pre-assigned overflow channels. If k = n, all overflow channels are available for this purpose and the notion of an a priori notion is superfluous. However, if k < n, the choice of overflow channels for a traffic channel, overactive, given is restricted by pre-allocation. The impediment occurs if any of the superactive traffic channels can not have their access capacity managed by the a priori assignment of the overflow channels. The case where k = n is referred to as a fully dynamic allocation strategy. For a completely dynamic allocation strategy, the P1550 / 97MX impediment will occur if, and only if the number of superactive traffic channels exceeds n, so that if each of the b active channels is superactive with the probability of p and if these cases are statistically independent, then the probability of impediment will be: # * / *** «* > ) = i? (v_ *)! , p'p-p '(3) where ? is the overflow channel number provided for each user's use. If k < n, the impediment can be caused by the additional constraints imposed by the a priori assignment of the overflow channels, to the active traffic channels. In particular, if k < n, the impediment can occur even if the number of superactive channels is less than n, the number of overflow channels. If k < n, the above formula is a lower limit on the probability of impediment. In order to simplify the design of the receiver, it is better to find a priori allocation strategies where k is small. Specifically, it is an object of the present invention to provide an allocation strategy, whereby when a call is established, a traffic channel and a set of k (n >) are pre-assigned (in each satellite downlink).; k > 1) channels P1550 / 97MX overflow The receiver for this call then knows that if the assigned traffic channel becomes superactive, the extra data will be transported on one of these k overflow channels. The choice of one of these k overflow channels that will be coupled with the traffic channels is called post-allocation. A first method of allocation and post-allocation is illustrated by the following example. In the case of k = 3 and n = 6, each of the traffic channels is pre-assigned to three of six overflow channels. The overflow channels are marked by the letters A, B, C, D, E, and F. At the moment assume b = 10 active traffic channels that are marked by symbols 0, 1, 2, 3, 4, 5 , 6, 7 8, and 9. In Table I, an example assignment is illustrated by means of which overflow channels are pre-assigned to these ten traffic channels. In this table, the columns refer to the overflow channels and the rows refer to the traffic channels. The "" first "k = 3 in a particular row indicates the K = 3 overflow channels that have been assigned to that traffic channel, eg the overflow channels A, B, and D have been assigned to the traffic channel 0 .

P1550 / 97MX TABLE I CHANNEL OF TRAFFIC CHANNEL OF OVERFLOW ACTIVE ABCDEF 0 1 1 0 1 0 0 1 1 1 0 0 0 1 2 1 0 1 1 0 0 3 1 0 1 0 1 0 4 1 0 0 0 1 1 5 0 1 1 0 1 0 6 0 1 1 0 0 1 7 0 1 0 1 1 0 8 0 0 1 1 0 1 9 0 0 0 1 1 1 The "" impartiality "of this allocation is reflected in the fact that there are exactly r = 5 traffic channels that are assigned to each overflow channel and exactly 1 = 2 traffic channels that share the collective allocation of each pair of overflow channels. The methods by which this table and future tables are constructed are described later in this document: If six or less traffic channels become superactive, each of these superactive traffic channels can be assigned to an overflow channel.

P1550 / 97MX only. For example, if the channels associated with the traffic channels 0, 2, 3, 5, 8, 9 become superactive, Table I would allow the post-allocation of the traffic channel to the overflow channel to be (0, A ), (2, C), (3, E), (5, B), (8, D) and (9, F). However, if the channels associated with the traffic channels 0, 1, 3, 5, 8, 9 become overactive Table I would allow the pos-assignment (0, A), (1, B), (3, C) , (5, E), (8, D) and (9, F). It is pointed out in this example that the post-assignment for the superactive channel 3 was changed although it was superactive in both sets. In summary, for the pre-allocation described in Table I, there will be no impediment, unless, the number of superactive channels exceeds the number of overflow channels. In this way, this assignment works as well as the completely dynamic allocation strategy and the previously given form for the impediment applies in this case. Even the receiver is simpler, since only one of three possible channels of overflow can be coupled with any particular traffic channel. Where each active traffic channel is assigned to three of six overflow channels, there is no case where the pre-allocation of overflow channels to active traffic channels would allow more than ten active traffic channels and have no impediment to six channels P1550 / 97MX superactive In the illustration, the case is considered where each active channel is pre-assigned to k of n overflow channels. An upper limit is sought for the number of active channels b, such that no overflow occurs if n or less active channels are superactive. For any allocation table with b rows, n columns and k l's (l's means ones) space per row there will be a total of (kb) l's and ((n-k) b) O's (O's means zeros) in the entire table. In this way, the average number of O's per column is then ((n-k) b) / n. For no impediment with n superactive channels, the maximum number of O's in any column is (n-1). Since the maximum must be greater than or equal to the average ((n-k) b) / n = (n-l). The solution for b leads the next upper limit: b < n (n-l) / (n-k¡: 4) More generally, through the similar argument, that if you are not going to see overflow or if few active channels are overactive for 0 < a < n-k-l, then b must satisfy inequality b < v \ (\ '- k - a - \ V. (v - a - 2) { v ~ k) (5) P1550 / 97MX Returning to the case of a = 0, or k = 3, equation 5 becomes b < n (n-l) / (n-3) (6) It should be noted that for the special case of n = 6, the left side of equation 6 is equal to the integer 10. In this way, the correlation given in Table I has a value of b = 10 that is equal to its upper limit. Interestingly, the right side of Equation 6 is also an integer for the case of n = 9 producing the upper limit b < 12. An assignment with n = 9 channels of overflow that seems to allow nine of twelve active traffic channels to become superactive without any impediment, is given below in Table 2.

P1550 / 97MX Table II CHANNEL OF TRAFFIC CHANNEL OF OVERFLOW ACTIVE ABCDEFGHI 0 1 1 1 0 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 2 1 0 0 0 0 1 0 1 0 3 1 0 0 0 0 0 1 0 1 4 0 1 0 1 0 0 0 0 1 5 0 1 0 0 1 1 0 0 0 6 0 1 0 0 0 1 1 1 0 7 0 0 1 1 0 0 0 1 0 8 0 0 1 0 1 0 1 0 0 9 0 0 1 0 0 1 0 0 1 10 0 0 0 1 0 1 1 0 0 11 0 0 0 0 1 0 0 1 1 Returning now to the case of n = 6 overflow channels, it is assumed that it is desirable to adjust twice the number of active traffic channels, which is b = 20 active traffic channels. If it is required to achieve B = 20 without increasing the number of overflow channels, the pre-allocation shown in Table III can be used. It should be noted that the allocation for the first ten channels is P1550 / 97MX the same as in Table I, so that this assignment can be referred to as an included strategy. An included strategy can be used to generate a table for a larger number of traffic channels. By doing so, we start by generating a pre-allocation table for a certain number of active traffic channels and then add more active traffic channels without changing the pre-allocation for the original set.

P1550 / 97MX Table III CHANNEL TRAFFIC CHANNEL OVERFLOW ACTIVE A B C D E F 0 1 1 0 1 0 0 1 1 1 0 0 0 1 2 1 0 1 1 0 0 3 1 0 1 0 1 0 4 1 0 0 0 1 1 0 1 1 0 1 0 6 0 1 1 0 0 1 7 0 1 0 1 1 0 8 0 0 1 1 0 1 9 0 0 0 1 1 1 1 1 1 0 0 0 11 1 1 0 0 1 0 12 1 0 1 0 0 1 13 1 0 0 1 1 0 14 1 0 0 1 0 1 0 1 1 1 0 0 16 0 1 0 1 0 1 17 0 1 0 0 1 1 18 0 0 1 0 1 1 19 0 0 1 1 1 0 550/97 X The "" fairness "of the pre-allocation given in Table III is reflected in the fact that there are now exactly r = 10 traffic channels that are assigned to each overflow channel and there are exactly 1 = 4 traffic channels that share the same traffic. However, in this case, this new assignment can not adjust any set of six overactive channels, for example, if the channels assigned to channels 9, 15, 16, 17, 18 and 19 of active traffic, are superactive, can not be assigned to unique overflow channels since none of the active traffic channels have been pre-assigned to overflow channel A. That is, at most five overflow channels are available for these six superactive channels The proportion of cases of six superactive channels that can not be adjusted by this assignment is: 6 (C? ~? o) x = _. 0"3" 2"5, - en_ djonde_ C" e10 indicates the number number of combinations of t objects However, it is true that this new allocation will adjust, adjust any set of five or less superactive channels. As discussed above, one method to adjust more active traffic channels is to mitigate the requirement with respect to the impediment. Another method is P1550 / 97MX Increase the number of overflow channels. The present invention describes methods by which both approaches are followed. A simple method to adjust twenty active traffic channels in such a way that the impediment will not occur, if six or less active traffic channels become superactive, is to use twelve overflow channels and use an allocation as in Table I, to assign the first ten traffic channels to the first six overflow channels and then use this same allocation to assign the last ten traffic channels to the last six overflow channels. This is another example of a strategy included. There are several methods for post-allocating overflow channels to superactive traffic channels consistent with a given pre-allocation table. Returning to the design of the pre-allocation tables, an allocation table for n overflow channels is called complete if their rows consist of all vectors with exactly k l's. An example of this complete allocation table is given in Table 2 for the case of 6 overflow channels. From the above, a complete allocation table will adjust b = Cv active channels. The number of active channels that can be adjusted by a complete allocation table with n overflow channels is P1550 / 97MX given in Table IV.

TABLE IV PARAMETERS FOR THE COMPLETE ALLOCATION TABLE (? = 3) Number of overflow channels, n 6 7 8 9 Number of active channels, b 20 35 56 84 120 Since there are a total of 128 channels available in a Globalstar system, if a full allocation table were used, 118 active traffic channels with ten overflow channels could be set. For a complete allocation table, each set of i overflow channels is assigned to exactly C)? =? V ~ active traffic channels for i = l, 2 ... k. For example, for the case of k = 3, the complete allocation table has the properties: 1. Each overflow channel is assigned to exactly C2V and active traffic channels. 2. Each pair of overflow channels is assigned to exactly C ^ "= v-1 active traffic channels 3. Each set of overflow channels is assigned exactly CQV" = 1 active traffic channel. Similarly, for a complete allocation table, for each set of i overflow channels P1550 / 97MX where i = l, 2, ..., n-k, there are exactly Ckv ~ active traffic channels that are not assigned to any of the overflow channels in the set. For example, for the complete allocation table of Table II with n = 6 and k = 3. 1. Each individual overflow channel is not assigned to C3 = 10 active traffic channels. 2. Each pair of overflow channels has C3 6-2 = 4 active traffic channels that are not assigned to any of the overflow channels in that pair. 3. Each set of overflow channels has C3 = 1 active traffic channel that is not assigned to any of the overflow channels in that trunk.

If the probability and request for a complete assignment is too high, the rows of the complete allocation table can be eliminated. The result is an allocation table that can adjust fewer active traffic channels but has better impediment performance. The process to further eliminate the rows can be repeated to arrive at another table, again it can adjust even less active traffic channels but it still has a better performance in the impediment. These tables are considered to be included, since the rows of a smaller table in this set of tables will be a subset of the rows in a larger table in this list P1550 / 97MX of tables. A set of included allocation tables is convenient for several applications. When traffic is light, the smallest allocation table is used in this set that will adjust the number of active traffic channels. When traffic is increased to the point where the number of active traffic channels exceeds the maximum number for the allocation table in question, a new allocation table is adopted in the included set of tables, which can adjust the largest number of channels of active traffic but allows the present calls to maintain their original allocation of overflow channels. If tables not included are used, the allocation of the overflow channels may have to be changed for a call in the middle of a call. General methods for designing pre-allocation tables are now described, although there are alternative, easily derivable techniques. The method considered here employs the theory of incomplete, balanced block designs for the design of these tables. In block design terminology, overflow channels are called objects and active traffic channels are called blocks. A block design is an arrangement of n objects in b blocks subject to certain rules that relate to the occurrence of objects and pairs P1550 / 97MX of objects. An incomplete block design, balanced with parameters (b, n, r, k, 1) is a block design such that: 1. Each block contains the same number, k, of objects. 2. Each object occurs in the same number, r, of blocks. 3. Each different pair of objects occurs in the same number, 1, of blocks An allocation table that is based on an incomplete, balanced block design is a matrix of b rows by n columns of the O's and l's with a 1 in the ith row and the jth column if and only if the jth object occurs in the i-th block. There are two relationships in the five parameters that can be easily verified: bk = nr, and (7) r (k-l) = 1 (n-1) (8) Equation 7 results by counting the number of l's in an allocation table first by the rows and then by the columns. Equation 8 results by counting the pairs of l's in the rows of an allocation table, first by pointing out that in any column there are r l's and each one can be paired with k-1 other l's and alternatively that l's in P1550 / 97MX any column equals the l's in any of the (n-1) other columns in exactly I places. The special case of k = 3 has received special attention and a block design, incomplete, balanced with k = 3 is called a triple system. It is pointed out that a triple system corresponds to an allocation table where each specific traffic channel is assigned exactly to k = 3 overflow channels. For a triple system, the previous equations can be rephrased as: r = l (n-l) / 2, and (9) b = ln (n-l) / 6 (10) In this way, the conditions necessary for a triple system to exist are: l (n-l) = 0 module 2 (11) ln (n-l) = 0 module 6 (12) These last two congruences are both necessary and sufficient for the existence of a triple system (n, b, r, k = 3, 1). It should be noted that for all values of n > 3, the complete allocation table for k = 3 produces a triple system with b = C3V and l = (n-2). Additionally, all P1550 / 97MX Allocation tables based on any triple system must be included within one of these designs. The special case of a triple system when 1 = 1 is called a triple Steiner system. For a Steiner triple system, the above congruences are reduced to: n = l or 3 modules 6, so that all values of n can be used for Steiner systems. The methods for constructing block designs fall into two broad categories: repetitive and direct. The repetitive method is a way to build designs from smaller ones, while the direct method allows the construction of special values of the parameters. Most direct methods make use of special properties of finite fields or congruences. An example of the direct method is an allocation table based on a design (b = 35), n = 15, r = 7, k = 3, 1 = 1) constructed from sets of differences, given below in the Table V.

P1550 / 97MX TABLE V 97MX TABLE V (CONTINUED) OVERFLOW CHANNEL CHANNEL OF TRAFFIC ACTIVE A B C D E F G H I J K L M N 0 16 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 17 1 0 1 0 0 0 0 0 0 1 0 0 0 0 0 18 0 1 0 1 0 0 0 0 0 0 1 0 0 0 0 19 0 0 1 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 1 0 0 '21 0 0 0 0 1 0 1 0 0 0 0 0 0 1 0 22 0 0 0 0 0 1 0 1 0 0 0 0 0 0 1 23 1 0 0 0 0 0 1 0 1 0 0 0 0 0 0 24 0 1 0 1 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 1 0 0 0 0 26 0 0 0 1 0 0 0 0 0 1 0 1 0 0 0 27 0 0 0 0 1 0 0 0 0 0 1 0 1 0 0 28 0 0 0 0 0 1 0 0 0 0 0 1 0 1 0 29 0 0 0 0 0 0 1 0 0 0 0 0 1 0 1 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 31 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 • 32 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 33 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 34 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 reference to Table 5, the rows from 2 to 14 are 97MX cyclic permutations of row 1; the rows from 16 to 29 are cyclic permutations of row 15; and rows 31 through 34 are cyclic permutations of row 30. The following is a method for estimating the probability of impairment, for a superactive traffic channel, for the pre-allocation and post-allocation methods described above. A particular superactive traffic channel is blocked where that particular superactive traffic channel can not be assigned to an overflow channel in the post-allocation process. It is assumed that there are b active traffic channels, n overflow channels, and that each active traffic channel is preassigned to k (of the n) overflow channels. Let Aj be the case that exactly j, 0 < j < b, b of sub-traffic channels are superactive and it is assumed that the statistical data describing this case are binomial; that is to say, PriAi, = í ^) piíl "p) K D < p < 1 '(13) where denotes the binomial coefficient "" b choose j ".

Bi is defined as the case that the particular overactive traffic channel is the i-th traffic channel P1550 / 97MX superactive that is going to be assigned in our interest, in the post-assignment process. Assuming that since there are j superactive traffic channels to be assigned that the interest is probably equal to having "any place in line" (from 1 jc) in the post-allocation process, mathematically, this can be raised as: PrjBi I Aj} = l / j, i-1.2 j. (14) Finally, a simplification assumption can be made near the pre-allocation table. It is assumed that the pre-allocation is such that when a post-assignment is made for any overactive traffic it is probably equal to being assigned to any of the n overflow channels. A case where this assumption would be valid is when the rows of the pre-allocation table are chosen randomly and with equal probability (from the possible ways to choose the rows with k l's and (n-k) O's). It should be noted that certain balanced determi- nation assignments could also lead to condition. Under these assumptions, the probability of impediment, denoted Pr { impediment], for any particular overactive traffic channel, can be calculated. East P1550 / 97MX calculation is done by conditioning in cases Aj and B and then by averaging over these cases. This is Pt \? Veé tvto \ - ¿Pt \? * PeémanO I Aj, Bi) Pr | Bj I Aj} Pr | Aj | (15) j = l? «L / pi (l-p) M. (16) where use is made of the fact that Pr { impediment | Aj, Bi} = Pr. { impediment | Bi} It is considered that the diagram shown in Figure 9 that is related to the case where the superactive traffic channel in question is the i-th in line that will be post-assigned. The branches are marked with probabilities and the index of the states refers to how much of the overflow sub-channels of the superactive traffic sub-channel in question has been used to post-allocate them to other superactive traffic channels that are ahead of it in the process of post-assignment. Assuming that i > 1, and starting at the S (0) and post-assignment state, the first sub-channel of superactive traffic is post-assigned. With the probability (k / n) it is assigned to one of the overflow channels of the superactive traffic channel in question and with the probability l (k / n) it is not assigned to one of the overflow channels. If P1550 / 97MX above, this is in the state S (l), where the "1" indicates that 1 of the k overflow channels of the present superactive traffic channel has already been assigned whereas in the latter case, it remains in the S state ( 0). Assuming here i > 2, the process then moves to the post-assignment of the superactive, next traffic channel. It is continued in this way until all the i-1 superactive traffic channels that are in front of the one in question, are post-assigned. The probability in question, Pr { impediment | B? } is given by the conditional probability: Pr { impediment) \ B¡} = Pr { state = S (k) at time i-11 state = S (0) at time 0.}. . (17) The probability of equation 17 can be obtained by a generator function approach by additionally marking each forward path by ZI and each path that does not progress forward by Z. The generator function T (Z, I) can be described as follows : The probability of the impediment is then given as: P1550 / 97 X Px fapeanreoio) p 'O - P?' ¡? C (? - - l) (19) that can be computed. The prior description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. The various modifications of these modalities will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the modalities shown herein, but rather to the broader scope consistent with the principles and the new features described herein.

P1550 / 97MX

Claims (28)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. An apparatus for transmitting a variable rate packet of data symbols, comprising a variable number of data symbols, the apparatus comprises: a channel packer means for receiving the variable rate packet and when the number of data symbols exceeds a threshold value, dividing the variable speed packet into a packet of traffic and at least one overflow packet; a transmission means for transmitting the variable rate packet in a traffic channel when the number of the data symbols is below the threshold value and for transmitting the traffic packet in the traffic channel and at least one overflow packet in at least one overflow channel when the number of data symbols exceeds the threshold value, wherein each of the at least one overflow channel is orthogonal to the traffic channel. The apparatus according to claim 1, wherein the transmission means comprises: a modulating means for modulating the packet of P1550 / 97MX variable speed, to provide the variable rate packet in the traffic channel according to a first extended spectrum modulation format when the number of data symbols is below the threshold value and to modulate the traffic packet and to provide the traffic packet in the traffic channel, according to the first extended spectrum modulation format and for modulating at least one overflow packet, according to a second extended spectrum modulation format, to provide at least one packet of overflow in the at least one overflow channel when the number of data symbols exceeds the threshold value, wherein the first spread spectrum modulation format is orthogonal to the second spread spectrum modulation format; and a transmitting means for upconverting and amplifying the variable speed packet when the number of data symbols is below the threshold value and for upconverting and amplifying the traffic packet and at least one overflow packet when the number of symbols of data exceeds the threshold value. The apparatus according to claim 1, further comprising an overflow channel signaling means for transmitting a signal identifying the P1550 / 97MX minus one overflow channel. The apparatus according to claim 1, wherein the channel packer means for receiving a signal indicative of the at least one overflow channel and for combining the signal indicative of the at least one overflow channel and the traffic packet. The apparatus according to claim 1, wherein the channel packer means for receiving a signal indicative of the at least one overflow channel for a subsequent variable speed packet and for combining a signal indicative of the at least one overflow channel for a variable speed packet, subsequent and the traffic packet. The apparatus according to claim 1, further comprising a variable speed vocoder means for receiving speech samples and for compressing the speech samples according to a variable speed vocoder format to provide the variable speed packet. The apparatus according to claim 6, further comprising a coding means positioned between the variable speed vocoder means and for the error correction coding of the variable speed packet. 8. The apparatus according to claim 7, which P1550 / 97MX further comprises an interposer means positioned between the encoder means and the variable speed vocoder means for reordering the variable speed packet. The apparatus according to claim 6, wherein the variable speed vocoder means is additionally for compressing the speech samples according to a second variable speed vocoder format, to provide a variable, alternative speed packet and wherein the channel packer means is additionally for selecting a variable speed packet for transmission from the variable speed packet and the alternate variable speed packet. The apparatus according to claim 1, further comprising a cell controller means for providing an overflow channel availability signal and wherein the channel packer means is responsive to the overflow channel availability signal. 11. A method for transmitting a variable rate packet of data symbols comprising a variable number of data symbols, the method comprising the steps of: receiving the variable rate packet; divide the variable speed pack into a traffic packet and at least one overflow packet, P1550 / 97MX when the number of data symbols exceeds a threshold value; transmitting the variable speed packet in a traffic channel when the number of data symbols is below the threshold value; and transmitting the traffic packet in the traffic channel and at least one overflow packet in the at least one overflow channel when the number of data symbols exceeds the threshold value, wherein at least one overflow channel is orthogonal to the channel of traffic. The method according to claim, wherein the step of transmitting the traffic packet in the traffic channel and at least one overflow packet in the at least one overflow channel, comprises the steps of: modulating the traffic packet to provide the traffic packet in the traffic channel according to a first extended spectrum modulation format; modulating at least one overflow packet according to a second spread spectrum modulation format to provide at least one overflow packet in at least one overflow channel, wherein the first spread spectrum modulation format is orthogonal to the second overflow format. extended spectrum modulation; convert upwardly the traffic packet and P1550 / 97MX at least one overflow packet when the number of data symbols exceeds the threshold value; and amplifying the traffic packet and at least one overflow packet when the number of data symbols exceeds the threshold value. The method according to claim 1, further transmitting a signal identifying at least the overflow channel. The method according to claim 11, further comprising combining the signal indicative of the at least one overflow channel with the traffic packet. The method according to claim 11, further comprising the step of combining a signal indicative of the at least one overflow channel for a subsequent variable rate packet and the traffic packet. The method according to claim 11, further comprising the steps of: receiving speech samples; and compress the speech samples according to a variable speed vocoder format to provide the variable speed packet. The method according to claim 16, further comprising the error correction coding step of the variable speed packet. 18. The method according to claim 17, which P1550 / 97MX it further comprises the step of reordering the variable speed packet. The method according to claim 16, wherein the step of compressing the speech samples further comprises compressing the speech samples according to a second variable rate vocoder format to provide an alternative, variable speed packet. The apparatus according to claim 11, further comprising the step of providing an overflow channel availability signal. 21. A system for transmitting a variable rate packet of data symbols comprising: an interleaver device having an input and having a first output for transferring the variable rate packet when the number of data symbols in the speed packet variable is less than a threshold and to transfer a first portion of the variable speed packet when the number of data symbols in the packet is greater than the threshold and that it has a second output to transfer a second portion of the variable speed packet when the number of data symbols in the variable-speed packet is greater than the threshold; a first modulator having an input coupled to the first output of the interleaver device and P1550 / 97MX that has an exit; and a second modulator having an input coupled to the second output of the interleaver device and having an output. 22. The system according to claim 21, further comprising a variable data source coupled, that has an entrance and that has an exit. The system according to claim 22, further comprising a selector positioned between the variable speed data source and the interleaver having an input coupled to the output of the variable speed data source and having an output coupled to the input of the interleaver device. The system according to claim 23, wherein the selector having a second input and the system further comprising a cell controller having an output coupled to the second input of the selector. 25. An apparatus for receiving a variable rate packet of data symbols, comprising: a traffic demodulator means for demodulating a received traffic packet according to a traffic demodulation format to provide a demodulated traffic packet; at least one overflow demodulator means for P1550 / 97MX demodulating an overflow packet received in accordance with an overflow demodulation format, to provide at least one demodulated overflow packet, wherein the overflow demodulation format is orthogonal to the traffic demodulation format; and a combining means for combining the demodulated traffic packet and at least one demodulated overflow packet to provide the variable speed packet. 26. The apparatus according to claim 25, further comprising a decoding means placed between the traffic demodulator means and the combiner means for selecting a demodulated overflow packet from at least one demodulated overflow packet. The apparatus according to claim 26, wherein the decoding means combines the demodulated traffic packet and each of the at least one demodulated overflow packet and decodes each combination to determine a selected overflow packet. The apparatus according to claim 27, wherein the decoding means decodes the traffic packet to determine an overflow channel identification signal and wherein the at least one overflow demodulation means is responsive to the channel identification signal of overflow. P1550 / 97MX