CA2167502A1 - Dynamic radio communications system - Google Patents

Abstract

A communication system includes a plurality of subscribers each of said subscribers having a transceiver including a transmitter (34) and a receiver (35, 36). In the system there are means (31) coupled to each of said transceivers to enable said transmitter to transmit a unique waveform having a predetermined time, frequency and phase code and each transceiver includes means (32, 33) coupled to the receiver to enable anayone of said suscribers to receive any transmitted waveform while others of the suscribers including those receiving said waveform can simultaneously transmit other unique waveforms whereby any suscriber can receive any transmittes waveform while simultaneouslt transmitting another waveform.

Description

wo gS/044~ 7 5 Q ~ PCT/US93107237 DYNAMIC R~DIO COMMUNICATIONS SYSTEM

TI~CHNICAL liIELD OF THE INVENTION
This invention relates to a communications system in general and more particularly to a co"""l"~ications system which increases conllnullication capacity, while allowing for the simnlt~neous reception and tr~n.~mi~sion of data.

BACKGROUND ART
Existing co,n"~ll"ication systems are sender directed. That is, such systems enable a calling or a tr~n~mitting party to contact any one of a plurality of receivers to transmit and receive data to and from the called receiver based on a connection. The sender directed system operates to provide a coll"l,ul,ications link one at a time. In this way, either a dçci~n~ted frequency or some code intlic~tive of each location is a messenger. For example in systems such as telephone systems, any party can call another party within a wide spectrum of subscribers or conference calls can be made.
Subscribers require the dialing of a unique code whereby each subscriber to the systems has a code (telephone number~ at which he can be reached. Thus, connections can only be made based on the knowledge of this code or based on a particular frequency in regard to other systems and so on. Such systems do not allow independence of use or concurrency. They require either time connection or compatible frequencies to afford communications. The system enables only "called" parties to communicate with "calling" parties.
The present system, which will be described, operates in a manner to provide independence of use while providing omni-directional propagation in the radio medium. The present system is capable of concurrent activities through multiple sources and essentially allows information ~xch~n~e which results from use of a time dispersed retllmd~ncy coded signal format wo 95~04415 2 1 6 7 5 0 2 - 2 - PCT/US93/07237 which also allows timing and access flexibility, concurrency, and independence of users and usages. The system to be described is distinctly different from thetraditional systems as the system supports simultaneous tr~3ncmiccions where alltransmitted signals are presented at each site for reception, even if the transceivers are tr~nsmitting to and receiving from others.
As one will understand, the system operates similar to acoustic commllnications which occur at a cocktail party. In this manner a great number of people can communicate with each other or with anyone across the room and so on. Hence, each of the participants of a cocktail party can comml-nicate with any other person at that party and do so while talking and with more than one person listening or en~gin~ in the conversation. There is no comm-mication system according to the prior art which operates according to this analogy.
As will be explained, the present communication system allows every single subscriber to have access to every single tr~ncmitted message and to receive any message so desired with any message capable of being received by more than one unit and capable of being received while the unit is transmitting. Thus by elimin~ting conflicts, as compared to prior art communication systems the system increases capacity by an order of magnitude, gives each subscriber total accessibility to the community tr~ncmiccions, and allows each subscriber to select for reception only data which is relevant to itsel The system operation, essentially, can be analogized to the brief description of the cocktail party as indicated above.
The system is particularly suited for military comununications, as existing co"",~ ications equipment will not meet the requirements resulting in emerging operational needs to better coordinate dynamic tactical engagements. Traditional communication structures are poorly suited for the dynamics of coorrlin~ting functions such as sensor coordination, detection enhancement, targeting, maneuver coordination, weapon coordination, and kill assessment.

wo 95/04415 2 1 6 7 5 a 2 PcTluss3lo7237 .

The communications scenario for cooperative information sharing are characterized by nelwo~k~ or groups of subscribers with access to other - subscribers information. Each subscriber needs total access to coin~ ;Ly generated data and an ability to select for reception only data that is relevant.
Current channelized radio systems provide only fragmented connectivity, can not provide total ~cces~ibility, and suffer serious loss of a platform's tr~n~mic~ion capacity as its community size increases and receptions block use of tr~n~mitter. Identified needs for information sharing between force elements are real, can be expected to increase, and will overwhelm the capacity of existing structured comml-nication systems. The inability of traditional co~ lunications to support these needs will inevitably result in truncation of a group's real requirements, minim~l sharing of hlrollllation among groups, and thereby, reduced battle-force capability. Traditional radios, with their reliance on time and frequency guardbands have inefficient system capacity due to their inefficient use of time and frequency spectrum resources.
The basic cause of the inefficiency is traditional radio's inability to receive while concurrently tr~"~"~ g. As one will understand, a radio's trz~n~mitter always served as a j~mmin~ or interference source for its receiver.
In a collll~ y of diverse platforms and multiple media, effective data ç~ch~nge is frustrated by mi~m~tçhes in radio circuit structures,timing, and link protocols. These structures and protocols have been used to olgalli;~e participation to prevent tr~nsmitter blocking of receptions and vice versa. Many types of sequential access protocols have been developed to deal with the ;ullenL necessity for sequential, mntl-~lly exclusive tr~n~mi~siQns and receptions.
Data interoperability would benefit ~ignifi~ntly from technology which elimin~tes the need to protect receptions from tr~n~mi~ions. High quality, secure, economic, hear-while-talk, bandwidth efficient voice O col~llllul~ications is a long st~ntlin~ need. Previously, low cost voice ~ligiti7~tion solutions required too much bandwidth; lower bandwidth solutions required wo 95/04415 2 ~ 6 ~ 2 PCT/US93/07237 costly processing and are vulnerable to noisy acoustic environments.
Traditional radio's constraints also demand the complex pre~ignment of co~ ications resources. The communications planner pre~ign~ frequency channels in time slots in order to separate tr~n~mi~ ns and receptions while attempting to achieve the kind of activity that satisfies the missions coll....unications needs. A c~ ication system is needed which avoids the complexity of the co-~-..u--ication planners tasks; gives the platform more capacity, more autonomy, and dynamic platform-determined ~cce~ibility to data; and addresses the growing needs to support the real time engagement coordination functions.
Many communications systems employed today with their sophisticated spread spectrum and/or frequency hopping techniques tend to have poor reliability. Radios with good mission reliability will be more essential as information e~rch~nge between friendly forces becomes increasingly important to mission success. The communication system to be described has applicability in regard to military and other co-----,u. ication systems where the platform divel~iLy may inclllde aircraft, ground transportation, as well as sea-going vessels.
The overall object of this communication system is to increase available system communication capacity by an order of m~gnit~lde. The system provides total access to the comm~lnity's l.~ ions and overcomes today's fragmented connectivity. The system further allows each subscriber to dynamically select for reception only those data messages or voice that are relevant to that subscriber. The system enables hear-while-talk voice as a low cost function within the multi-function transceiver employed. The system further provides data inter-operability by use of a single common basic waveform structure and by avoidance of circuit oriented timing structures.
These and other aspects of the system provide improved mission reliability and simpler maintenance through a radio architecture based on pooled, simplified functional modules and automatic fault isolation.

~ WO 95/1~4415 ~ 6 7 5 ~2 PCT/US93/07237 DISCLQSURE OF THE INVENTION
A preferred communications system is the type inçhlding a plurality of subscribers forming a CO~ llul~iLy, each of said subscribers having a tramsceiver inchlrlin~ a transmitter and a receiver, comprising means coupled to each of said transceivers to enable said transmitter to transmit a unique wavefollll having a predetermined time, frequency and phase (TFP) code, and inclll(1ing means coupled to said receiver to enable any one of said subscribersto receive any tr~n~mitted waveform while other of said subscribers inchl(ling those receiving said waveform can simlllt~neously transmit other unique w~vefolllls, whereby any subscriber can receive any tr~n.~mitted waveform while cimlllt~neously tran~mitting another waveform.

BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a simple block diagram depicting a co".",~ y of subscribers to the system accordhlg to this invention.
FIG. 2 is a block diagram showing a typical transceiver employed in conjunction with this invention.
FIG. 3A, 3B, and 3C are diagrams depicting the timing forrnat employed by this invention.
FIG. 4 is a timing diagram and a pictorial showing comrnunications according to this invention.
FIG. 5 is a block diagram showing a data element group according to this invention.
FIG. 6 is a timing and flow diagram depicting the use of a processing element pool according to this invention.
FIG. 7 is a diagram depicting the time, frequency and phase patterns employed according to this invention.

wO 95/0441~ 2 1 ~ ~ ~ 0 2 PCT/US93107237~

BEST MODE FOR CARRYING Ol17r THE INVENTION
Referring to Figure 1, there is shown a plurality of units or users each of which is rlesign~ted by the letters T-R st~ntling for Transmit-Receive or transceiver such as units 10 and 11. As will be further explained, each of S the units as 10 and 11 can communicate with any unit, receive any data that is being tr~n~mitted and ~im~llt~neously transmit and receive. The units are shown arranged in a circular configuration which model is purely arbitrary and necessary just to explain the operation of the system and to show an important distinction from classic linear or one-tr~n~mitter-at-a-time, one-way channel models. As will be further explained, each of the units as 10 or 11 can be airborne, on the ground or at sea still enabling communication with any other unit. The size and geometry of the configuration shown in Figure 1 is arbitrary, and for the sake of an example is referred to as a commlmity.
The plurality of transceiver units or T-R units 10 and 11 enables the co~ y to exchange information and to receive and transmit h~l-llation which is important to other people or platforms in the collll Illlllily.
In this manner, one ,,,~xi,,,i,es the participant's ability to tr~n~mit, at highpower, outgoing data, voice, and positioning signals of potential importance to others. The others can be any of the units who have a need or desire to receive this information. Each T-R unit retains the ability to receive, generally at lower signal levels, incoming information of interest or importanceto himself. In this manner each of the T-R units can transmit at high power levels and concurrently receive at lower power levels information that is of interest to the particular T-R unit. This information exch~nge orientation is enabled by a time dispersed, redllnd~ncy coded signal format which also allows timing and access flexibility, concurrency, and thus independence of users and usages. It is distinctly different from the traditional orient~tiQn of maximi7inF
a commlmity's occupation of a frequency channel by requiring coor~lin~te-l, arranged use of time concentrated, self-blocking signal formats.

WO 95/0441~ PCT/US93/07237 2 1 675a~

Referring to Figure 2, there is shown a block diagram of a typical T-R unit such as 10 or 11 employed in the community of units as shown in Figure 1. It is noted that each of the T-R units in Figure 1 are of the format shown in Figure 2.
Shown in Figure 2 is a platform 20 which is indicated by dashed lines. The term platform indicates the type of unit that the particular transceiver is on or associated with such as an aircraft, a naval vessel or ground transportation such as a truck, jeep, tank and so on. Depending on the platform 20, the unit may be programmed in different ways.
Shown coupled to the platform is a central control module 21.
The central control module 21 initi~li7es the transceiver unit based on an initi~li7~tion load or control/display input from the platform. This essentiallytells the receiving unit or the radio which data functions to support. As will be explained, the platform as interfacing with central control 21 has certain requirements in the way of displays which may be located on the dashboard or in the cockpit. Hence each module is programmed via central control 21 in order to enable it to function at the most efficient level wi~h the platform requirements. As seen, central control 21 interfaces with a module 22 designated as resource control. Both central control and resource control may inclnde mini or microprocessors and contain memory and control.
Resource control 22 interfaces with the data or cignzlling control pool 23 and also interfaces with m~sc~ge and voice buffer modules 24. The mesc~ge and voice buffer modules 24 enables bidirectional collllllul~ications with the platform 20 in order to enable the platform 20 both to send mesc~ges and receive mesc~ges from and to the message and voice buffers 23. This occurs both in regard to digital messages as well as voice. The mecc~ge and voice buffers 24 also communicate with the data or signal control pool 23 via a two-way channel.
As one can ascertain from Figure 2, the data or cign~ling control pool 23 consists of a series of modules referred to as data element groups.

wo 95/04415 2 1 ~ 7 5 Q 2 PCT/US93107237~

Data element modules are arranged in groups and each T-R unit may have a plurality of such groups. Shown in Figure 2 there are 15 data elements associated with the T-R module depicted in Figure 2. There are five modules with three data elements in each modular group. The function of the data elements will be subsequently explained. As seen, each of the data elements receives inputs from the resource control 22 and the message and voice buffers 24, and each data element can communicate or send data to each of the modules 22 and 24. The eY~h~nge of information between data element groups and the resource control 22 and m~s~ge and voice buffers 24 is bidirectional.
As seen, each of the data element groups and each data element in the group, for example, interfaces with a matrix switch 30. The matrix switch 30 enables coupling to a pulse control module 31, a pulse control and correlator module 32, and an additional pulse control correlator module 33.
The pulse control module 31 is associated with the ~ ",i~ler 34 while the pulse control and correlator module 32 is associated with a first receiver 35 with the pulse control and correlator module 33 associated with a second receiver 36. It is understood that each of the T-R units may have more than one receiver and hence have more than one pulse control and correlator module as 32 and 33. It is also understood that a particular T-R unit can have more or less than 5 modular groups of data elements or may have more or less than three data elements in a modular group.
Each of the tr~n~mitter and receiver modules 34, 35, and 36 is associated with a RF front-end module 39 which module interfaces with a antenna 40. The antenna 40 is utilized for both receiving and transmitting.
The RF front-end 39 is capable of receiving the RF power signal from the tr~n.~mitter 34 for tr~n~mitting the same via the antenna 40 and can receive incoming signals from antenna 40.
Tr~n~mi~ion operation is as follows. The platform 20 initi~tes a tr~n~mic~ion sequence by sending message or voice data to the message and ~ wo 95/044~5 2 1 6 7 5 0 2 PCTrUS93/07237 voice buffers 24. The initiation of a tr~n~mi~sion request via the platform 20 may be made by the operator of the vehicle or, more typically by computers within the platform. The central control 21 comm~n~l~ the resource control unit 22 to begin the tr~n~mi~ion sequence. As indicated, both central control 21 and resource control 22 may cont~in micro-processors and essentially operate as co.l.~uLers as will be further explained. Resource control 22 searches the data or signal control pool 23 to find an available data element such as DE1 or DE6 within a group and so on. The resource control 22 selects and commands an available data element (DE) to begin the ~ign~ling waveform sequence which includes a preamble and a "TAG" which precedes every data tr~n~mi~ion also known as a "STRING". The selected data element performs related signal processing which determines the time, frequency, and code for each pulse of the ~ign~1ing's initial waveform, the preamble.
The preamble announces a tr~n~mi~ion to the collmlunily and allows synchlo~ aLion to the tr~n~mi~ion as will be explained. The signal processing in the transceiver shown in Figure 2 occurs while the data element prepares for the dispersion of the tr~n~mitted signals in frequency and code and uniquely in time. Just prior to the scheduled time for tr~n~mi~ion of each preamble pulse, the single pulse's time, frequency, and code parameters are dispatched by the data element through the matrix switch 30 to the tr~n~mitter's pulse control unit 31. The pulse control 31 operates to tune the tr~n~mitter's frequency synthesi~er or local oscillator and in real time controls the modulation and tr~n~mi~ion of the single preamble pulse. The selected data element co~ les this process until all preamble pulses are tr~n~mitte-l Then the data element is returned to the control pool 23 and is available for another a~ nment. While the preamble is being L~a~ ed, the resource control module 22 selects and comm~ntl~ another data element from the data or ~ign~ling control pool 23 to begin ~ign~lling the tag-waveform sequence.
The tag, which follows every preamble tr~n~mi~ion, contains encoded data which identifies the upcoming data tr~n~mi~ion and provides the WO 95/04415 2 t 6 7 5 0 2 PCT/US93/0723~

tr~n~mi~cion-security (TRANSEC) seed that will be used for the data waveform generation. The selected data element performs the TRANSEC-related signal processing which determines the time, frequency, and code of each pulse in the tag. It also adds coded redlln~l~ncy.
As the time of tr~n~miccion of a pulse approaches, the time, frequency and PN code parameters for the single pulse are dispatched through the matrix switch 30 to the transmitter's pulse control module 31. As for the preamble, the pulse control 31 provides real time control during the tags pulse tr~n~mi~ion and is then available. The data element continues its disp~tching process until all tag pulses are tr~ncmitted; it is then returned to the control pool 23 and 15 available for another ~ignment. While the tag tr~n.cmi~ion is under way, the resource control 21 selects another data element from the pool for the data string (wave form sequence). The message and voice buffers 24 send the data for tr~n~mi~ion to the selected data element which perforrns the data encoding and the TRANSEC-related signal processing. Since both involve data words, the data sequence is essentially the same as the tag sequence as described above. The data element continues its data processing until the end of the data tr~ncmic~ion. This completes a single tr~n.smi~ion sequence. Multiple concurrent tr~n.~mi~ion sequences can occur. For example, assume that a long voice tr~n~mi~ion is under way when new data is received from the platform. Another tr~nsmi~ion sequence would be started. Other data elements would be assigned to its operations which parallel the ongoing tr~n~mi~ion. Each active data element would individually access and send pulse parameters to the transrnitters pulse control 31 via the matrix switch 30.
The above noted description briefly describe the tr~ncmi~ion mode of the modules depicted in Figure 2. During reception the radio becomes synchronized to the community (network) time through a net entry process. Assume that the radio has successively completed net entry.
Resource control æ next assigns a data element to the reception processing for ~ wo 95/04415 2 ~ 6 7 5 0 ~ PCT/US93/07237 the ~ign~ling's preamble. A preamble signal can be received at any time, so this is a contimling ~ignment. The preamble's pulses are separated by a time that is greater than the propagation time to the furthest subscriber. The data element contin~ ly performs preamble signal processing and via the matrix switch 30 selects one of the receiver's pulse control and correlator elements as32 and 33 for the reception and correlation of the current preamble pulse.
The receiver as 35 and 36 is open for the entire range uncertainty time and reports all detected pulses and each time of arrival (TOA) back to the data element.
Each preamble has N pulses (N is selected at 16) and a preamble detection is declared when M of N pulses at nearly identical range are detected. This processing which detects multiple concurrent preambles from the cO~ llulliLy is also performed by the data elements. The detection of multiple concurrent preambles employs an algorithm to detect preamble pulses based on frequency, amplitude and time. A data element is assigned or selected by the matrix switch and is coupled to the pulse control and correlatorto do such proces~ing. The TOA of a detected preamble is reported to resource control 22 which selects and comm~n~l~ a data element from the pool 23 to begin the signal processing for the tag waveform. As with tr~n~mi~ion, the data element performs the TRANSEC-related signal processing which determines the time, frequency, and code for each pulse of the tag. On a pulse by pulse basis these parameters are dispatched via the matrix switch 3() to one of the receivers pulse control and correlator elements 32 and 33 for the reception, correlation and data demodulation of each tag pulse. The pulse control and correlator 32 and 33 sends the detected data character back to its controlling data element. When all pulses of a code word have been received, the code word is decoded to overcome character errors or erasures. The data element sends the tags TOA and its decoded data to resource control 22 and returns to idle.

wo 9510441~ 2 ~ ~ ~ 5 ~ ~ PCT/US93/0723~

As noted with the tr~ncmiccion sequence, the T-R unit is controlled by central control's 21 interpretation of initi~li7~tion load or control/display inputs from the platform 20. The platform 20 instructions identify which data types the radio should receive and send to the platform 20.
Central control 21 formats and sends this list of relevant data types to resource control 22. The received tag's data inclllrles the identity of its following string data or voice tr~ncmiccion and TRANSEC seed that will be used by the transmitter for the data waveform generation. The tags data ID is compared to the platform's list of relevant data. If there is no match, the data is not pursued. If there is a match, resource control 22 selects a data element for itsreception and gives the element the data waveform's expected TOA and TRANSEC seed. Using the tr~ncmitter's TRANSEC key, the data element determines the time, frequency, and code for each data pulse. As with the tag these parameters are dispatched per pulse to an available receiver as 35 and 36 via the associated pulse control and correlator 32 and 33. The received characters are formed into words, decoded and sent to the mçsc~ge and voice buffers 24. The data is then dispatched to the platform 20 which completes the data reception sequence. Multiple concurrent receive operations will be the rule rather than the exception. Tr~ncmiccions begin when data is available, not at pre~cciEned times.
In this manner the commlmiçation planner's complex task of allocating time slots, as with a time division multiple access (TDMA) system, is elimin~te~l With a large commnnity there can be a substantial number of concurrent tr~ncmiccions from its members. Thus multiple data elements will be concurrently assigned to the reception of preambles, tags and relevant data.
The size of the data or cign~ling control pool 23 is primarily determined from the expected concurrency of received tag and relevant data sequences. ~e data or cign~ling control pool 23 also supports tr~ncmiccions. The necessary number of receiver and pulse control and correlator combinations is determined from the number of pulses that one expects to receive 0~ wO 95/0441~ ~ 1 6 7 ~ O :2 PCTlUS93/07237 cimlJlt~neously. As shown in Figure 2 the architecture of the TR unit includes queued pools of data elements as for example three in a group and pools of receivers as 35 and 36 and pulse control and correlator modules 32 and 33.
The architecture has benefits in that there is a commonality of modules and S as an integral part of normal operation there is a ready isolation and by-passing of a faulty common module such as a faulty data element or a faulty receiver and so on.
In referring to Figure 3a, Figure 3b, and Figure 3c there is shown the timing and waveform structure which is employed in the system described herein. As will be explained the systems time-dispersed signal waveform removes the basic road block to efficient information exçh~nge among the various members of the community as for example shown in Figure 1.
Information çx~h~nge within today's radio commllnities is hampered by the inefficiencies of traditional radio technology. Traditional transceivers using time concentrated cign~lc, are limited to the two extremes of tr~ncmitter (intra-tr~ncmicci(m) duty factors, 0.00% (off or not transmitting) and 1.00% (on or not receiving) and therefore cannot receive while tr~ Just as the deleterious effects of frequency concentrated jammers can be avoided by frequency dispersion, the effects of time concentrated selfj~mminp; caused by ones own transmitter can be avoided by time dispersion and redundancy coding of the tr~ncmitted signal. By dispersing its transmitted signals in frequency and more ~mcl~mentally in time and by recllln-l~ncy coding, the transceivers accordhlg to this invention operate at intermediate (intra-trzln.cmiccion) tr~ncmitter duty factors which permit reliable receptions while concurrently transmitting. The achievement of a receive while transmit capability allows the elimin~tion of circuit structures and protocols whose basic goal was the separation of time-concentrated tr~ncmiccions and receptions. The avoidance of separation structures and protocols permits much greater use of the time and frequency spectrum and thereby provides at least of order of mzlgnitll(le increase in useful capacity. The avoidance of separation structures and WO 95/04415 2 1 6 7 5 0 2 PCT/US93tO72370 protocols also elimin~tes the complex pl~nning for ~imnlt~neous separations and intracommunity connections.
The system further simplifies communications pl~nning by not requiring the planner to predict and assign resources for peak mission S dynamics. Total access to the comm-lnity's data voice tr~n~mi~sions by each subscriber within a commllnity derives from the receive while transmit capability and the avoidance of separation structures and protocols. All data tr~n~mi~ions are preceded by a ~ign~ling waveform which identifies the data.
Total access to data means that each comm-lnity subscriber receives all ~ign~ling waveforms and is thereby notified of impending data tr~n.~mi~sion~.
Since the transceivers can receive (~ign~ling) at all times, the sign~lin~
waveforms from all other subscribers are received. None are blocked, as with traditional radios, by channelization or selfj~mming tr~n~mi~ions or by circuit structures and protocols. In addition the pseudo-random time, frequency and phase code dispersed signals are compatible with antijam (A/J) and low probability of intercept (LPI) technologies.
As will be explained the transceiver's, as for example shown in Figure 2, .sign~ling capability notifies each subscriber of an impending data tr~n~mi~ion, and allows each subscriber to dyn~mic~lly select, for reception, only data (messages or voice) that are relevant to the subscriber. In this manner receive resources are not wasted by waiting for a data reception or by receiving non-relevant data. In contrast, the traditional receiver is pre~ignt?dto a function (for example voice) even though the function may be active only a small percentage of the time.
Referring to Figure 3 there is shown in Figures 3A, 3B and 3C
the timing and waveform structure employed in this system. The waveform which is transmitted as shown in 3A consists of a ~ign~ling group and a data string group. Basically the ~i~n~lin~ group consists of a preamble and a tag group which consists of two separate tags. The string group is used to transmit or receive data channels of voice or messages. As seen the string group can ~ wO 95/04415 2 1 ~ 7 5 0 2 PcTluss3lo7237 be up to four independent and time orthogonal 16k bits/seconds strings.
These strings can be merged into string sets (of two or more strings) to support data rates that are higher than one string can support. Even if four strings are active the data pulses within the strings are time orthogonal sets and will not mntll~lly interfere.
The data strings as shown in Figure 3A illustrate an example where four strings are grouped into three sets. For example strings A and B
are employed to support a 32k bits/second air-track reporting channel, string C is lltili~e~l for a 16k bits/second voice channel while string D is used for a16k bits/second report channel. Thus the data strings can be 1l~ili7e~1 in combination or individually. While 16k bits/second is shown as a typical data string it is bit rate, understood that other bit rates could be employed.
Basically as seen in Figure 3A the information string is a series of data pulsesthat are cry-ptographically dispersed in time, frequency and spread-spectrum space as for example by use of direct spre~-ling. String data is cryptographically enciphered. All parameters defining the characteristic of the string group inclll(ling partial seed data used for cryptographic detection and deciphering of the strings are broadcast within the preceding ~ign~ling group.
The ~ign~ling group as seen in Figure 3A consists of a series of cryptographically dispersed pulses and starts with a preamble that is used for coarse acquisition.
A cryptographic, pulse position modulation scheme is employed for the collllllll~-iLy-wide preamble waveform which ",i~i"~i~es mutual interference even when several participants are simultaneously bro~clc~ting a preamble. The preamble as seen in Figure 3A is followed by the first of two tag groups which identifies the type of data channels embedded in the forthcoming data strings. The first tag is used by receiving subscribers to determine if all, some or none of the string group war~ants reception. The tags embedded data is enciphered. The cryptographic seed used for first tag signal recovery and deciphering are known by the Co~ lulli~y. The first tag also WO 95/04415 ~ PCTIUS93107237 includes enciphered emitter-dependent seed to be used to recover and to decipher the second tag group in the forthcoming strings. The second tag defines the partitioning of the data strings into groups, the length of each string, and other string attributes needed to receive and reconstruct the channelized data.
In the system, any participant in the community as shown in Figure 1 can transmit data at any time thereby allowing rapid and open accessibility to the communication network. Thus the system does not require an a-priori mission set-up of transmit ~c~iEnment opportunity times such as required in prior art systems.
Again referring to 3A, a typical tr~n~mi~cion consists of the ~ign~ling and the data strings as shown in 3A and designated as panel ~
There are a series of pages. A page is defined as a 10 millisecond interval of time.
Shown in Figure 3B is a page interval which consists of a number of bin intervals. There are 800 bin intervals in a page. Panel C which is shown in Figure 3C shows the data relationship for the data channels where there is shown the two 16K bits/second strings which are string A and string B. String C and string D are shown in column form. It is seen that the pages consists of data characters as well as tracking information. Basically the figure also depicts how the data in each of the bins as defined is stored in~ (lin~ theparticular algorithms utilized for the different pages of data as shown in the format. Thus the entire structure of the waveform utilized in this system is depicted in Figures 3A, 3B and 3C. Referring to Figure 4 there is shown a typical scenario depicting several intra and inter flight participants and hypothetical tag and string activity. The composite transmitted waveforms are shown in panel B. Each participant is subjected to all ~ign~lling including preamble and tags and data string emissions in the theater or location (co"~t~ y). The upper histogram is the hypothetical composite (unfiltered) ~ WO 95104415 2 1 6 7 5 0 2 PCT/USg3l07237 tag and string activity at aircraft #3D which is shown for example in module 40. Module 41 shows the activity of aircraft lB and 2B and so on.
As seen each participant reads the tags to identify the data type and only passes through its filter and receives data strings suited to its mission role. As indicated in module 40, aircraft number 3D filtered string activity peaks at ten concurrent data strings and therefore its radio needs only ten dataelements to fulfill its peak data requirement. I'his can be seen basically in regard to panel B. Each of the aircraft depicted is capable of transmitting and receiving any of the strings and tags within the co~ lnity shown. As indicated a waveform for a 16K bits/second data rate is shown but as indicated above the system will accommodate alternative waveforms and data rates.
As one will further understand and again referring to Figure 2, the number of data elements which appear in a data or ~ign~lling control pool 23 is a function of the platform as for example aircraft, ground transportation and so on. All the transceiver configurations are similar but the number of data elements and receiving modes can be varied to match the host platform required data rates. Thus the data element which is the major T-R unit component acts independently as a signal processor of a string, a tag, or a preamble. These elements which are the data elements are dynamically assigned to either receive or transmit one string (or tag) at a time. This ~C~ignment can be under control of resource control module 22 operating in conjunction with the central control 21. The illustrated pool shown in Figure 2 of 15 data elements permits concurrent tr~n~mission and reception of 15 independent strings and/or tags. The data elements are networked to a set of receiving nodes and a transmit node as specified by means of the non-interfering crossbar matrix switch 30. These receiving and transmit nodes have no ~ffili~tion to a specific string or tag, but serve the pool of data elements on a pulse to pulse basis.
Referring to Figure 5 there is shown a more detailed block diagram of a typical data element group which basically consists of 3 data WO 95/044lS ~ 1 ~75Q2 PCT/lUS93l07237 elements namely as shown in Figure 5 as data element number 1, data element number 2 and data element number 3. Essentially each data element consists of a first and second controller 50 and 51 having hardware embedded therein.
The controller's essentially operate in conjunction with a master gate array 52 which is a progr~mm~ble array and which interfaces with randomaces memory 53 and 54. As seen, each of the data elements such as 55 and 56 have exactly the same configuration as the data element first described. The outputs of each of the data elements interface with a common-bus 60 which is directed to the resource control processor 22 shown in Figure 2 as well as to the message and voice buffers. Each data element has a separate output line 61, 62 and 63 so that it can be controlled and assigned accordingly. The data elements comm-mic~te one with the other in each of the groups and as such interface with a module 57 design~ted as interface logic with a gate array.
Essentially the module 57 cont~in~ suitable interface logic as well as an electronically erasable progr~mmz~ble read only memory module (EPROM) to enable the interface 57 to control a progr~mm~ble gate array for purposes of pel~olllling data element tasks as previously described. The module 57 interfaces with a look-up table which may be in the form of a EPROM 58 to enable progr~mming of the data element module in regard to task formations and so. The interface module 57 couples to the matrix switch such as switch 30 of Figure 2 and includes one bus for each of the data elements. Therefore as shown in Figure 5 for three data elements there are three buses coupled to the matrix switch. Further more, an input dçsign~ted on lead 65 iS directed to each data element module from the pulse control and correlator or PCC 33 or 32 shown in Figure 2.
As in~lic~ted previously the preamble signal can be received at any time. The preamble pulses are separated by time and the data element c~ ntinllously performs preamble signal processing and via the matrix switch selects one of the receivers pulse control and correlator elements for the reception and correlation of the current preamble pulse.

~ WO 95/04415 2 1 6 7 5 0 2 PCT/US93/07237 The data element as shown in Figure 5 cont~in~ processing elements such as the controllers 50 and 51 and further the interface 57 has its own processing capabilities. As indicated previously each preamble has a number of pulses and preamble detection is declared when a given number of pulses at nearly identical range are detected. The rather sophisticated processing which must detect multiple concurrent preambles from the connllunilies is also performed by the data elements as shown in Figure 5.
Referring to Figure 6 there is shown a block diagram depicting the pool of signal control data process elements 70 which essentially corresponds to the pool 23 shown in Figure 22.
As in~lic~ted in Figure 6 there is shown a tr~n~mitted signal which es~enti~lly constitutes a tag and a string. As one can see from the tag and string signals as depicted, the object of the present system is to transmit a series of pulses which are design~ted and different by having a unique time, frequency and phase pattern (TFP). In this way, each pattern which is basically defined in the ~ign~lling channel as indicated by module 78 is unique and co~ ltes a three dimensional pattern which is unique to each string tr~n~mi~ion. In this manner by knowing the pattern which is transmitted along with ~ign~lling information the receiver can continue to select the data that itrequires. Thus each of the data processing elements or data elements as employed in the data element group can be assigned to recognize different patterns as well as multiple patterns and select only those patterns and data which is necessary to the particular platform.
Thus the main aspect of this system is dispersion with re~llln~l~ncy whereby there is Llallsll~iLled unique time, frequency and phase (TFP) patterns which enable one to discrimin~te and select a unique three dimensional pattern as for example shown in Figure 7. The three dimen~i-)n~l pattern is described and depicted in terms of frequency and time. The shape or nature of the wave form as for example how the pattern is formed determines and enables each WO 95/04415 2 ~ 2 PCTrUS93/07237 receiving element to select and continue to respond to that pattern. The processing is done by the data element groups which are assigned.
For example as shown in Figure 6 a first pulse design~ted by reference numeral 80 iS followed by a second pulse 81, by a third pulse 82, S another pulse 83 and so on as shown by the dash line connections. This represents a particular pattern. Therefore, by means of the data elements which respond to the ~ign~lling channel one can now select that pattern 78 after it is known. In order to accomplish such results the platform has selection criteria as indicated by module 77. This selection criteria is programmed or selected by the platform thus the selection as indicated by module 73 iS implemented by selecting a string identity which fits the platformsinterest. The platform can select strings of data or mes~ges which it is concerned with as is indicated by module 71 and which strings of data are sent to the platform as in~ ted by module 72. The data processing elements can respond to the sync. The sync detection module 76 denotes that sync detection is performed by a assigned data element which also has a seed sequence stored therein to recognize the sync pattern. In this manner knowing the nature of the tr~n~mi~ions as for example in Figure 3 the detection of sync enables the data elements to now respond to the tag data.
As seen in Figure 6 the tag consists of the high access rate sync followed by the string ID and TFP code. The TFP code is the time frequency phase code which is unique and defines the particular signal pattern as for example shown in Figure 6. The tag collection module 75 which is another processing element controls the reception of the tag which essentially enables the selection module 73 to therefore select those tags of interest to the particular platform and therefore the strings associated with the tags as indicated by module 71. Once a tag has been defined and is an acceptable tag then the string collection module 71 controls the reception of the string which string has a l~ pattern as shown in Figure 6. It is immediately noted for example that many TFP patterns exist but the system is able to select all TFP

~ WO 95/04415 2 1 6 7 5 0 2 PCT/US93/07237 patterns or TFP patterns which are of interest to the platform depending upon the ~ag and thereafter collect the string of data associated with those patterns and with those tags.
Again, referring to Figure 7 there is again shown a plot of frequency versus time. There is depicted therein a unique three dimensional pattern 3esi~n~ted by reference numeral 90. The pulse pattern which is connected by the dash lines is unique in that it is specified in time, frequencya~d phase (TFP) and hence is different from any other pattern which for example may incll~le the various diLrerelll cros~h~tçh elements. By optimally using the three dimensional aspect of time, frequency and phase one can now select anyone of those ~ ",illed patterns from space. In this way each TFP
pattern can be discrimin~ted and selected. Further more, lltili7ing the TFP
pattern allows concurrent transmit and receiving by each platform. The reason for this is that the platform will transmit in a completely different 1~ patternthen it is receiving then when it is tr~ "lil~ . Thus based on strict randomness of the system one can transmit and receive based on such patterns and assure that there will be no interference as for e~ample implemente~l by conventional systerns.

Claims (20)

THE CLAIMS

1. A communications systems of the type serving a plurality of subscribers forming a community of interest, comprising a plurality of transceivers for use by said plurality of subscribers, each of said transceivers including a transmitter and a receiver and further comprising:
means for enabling said transmitter to transmit a unique waveform having a predetermined coding that is a function of time, frequency and phase;
means for enabling any of said receivers to receive any transmitted waveform from a transceiver used by one of said subscribers while at the same time another unique waveform is being transmitted from the transceiver associated therewith;
whereby any subscriber is enabled to use its transceiver to receive any transmitted waveform from a transceiver in use by any one of said plurality of subscribers while simultaneously transmitting another waveform; and wherein said any transmitted waveform includes a series of pulses comprising a transmitted message, each pulse of said series of pulses is a unique three dimensional patter in space manifesting said predetermined coding and further is characterized as having a tag following a preamble which tag contains encoded data identifying the upcoming data transmission portion of said transmitted message and wherein said preamble operates to announce a transmission for enabling any subscriber to synchronize to said transmission.

2. The system according to claim 1, wherein said tag defines a seed employed for a message generation.

3. The system according to claim 1, wherein each preamble includes N pulses, wherein said transmitted message contains N and M pulses where M
and N are positive integers with M being at least 10 times larger than N.

4. The system according to claim 1, wherein said receiver further includes means responsive to any transmitted message to receive and detect said transmitted message and to provide an indication of a time of arrival of a detected message.

5. The system according to claim 4, wherein said detected message is the preamble and means responsive to a detection of said preamble to process a received signal to detect a tag waveform.

6. The system according to claim 5, including means responsive to said tag waveform to process said waveform to determine said predetermined coding for each pulse associated with said tag.

7. The system according to claim 1, wherein said tag comprises a first and a second tag, with said first tag operative to identify the type of data contained in said transmitted message and further includes seed information necessary to decipher the second tag information and the data contained in said message with said second tag defining the partitioning of the data contained in said message into groups.

8. The communication system according to claim 1, wherein each transceiver further comprises, an antenna means including an RF front end which operates to receive and transmit signals for coupling to a separate transmitter and receiver.
and wherein said transmitter is coupled to a pulse control means for applying predetermined pulses to said transmitter to be transmitted by said antenna via said front end, and means coupled to said pulse control means for selecting a pulse format for transmission of said message.

9. The communication system according to claim 8, wherein said means coupled to said pulse control means includes a first central control processor responsive to said subscriber to provide a control output signal indicative of the transmission sequence associated with said subscriber, a resource control processor coupled to said central control processor operative to commence a transmission sequence, a plurality of data elements having input ports and output ports with the input ports coupled to said resource control processor and with the output ports coupled to said pulse control means, said resource control processor operative to select and of said data elements to begin transmission and processing of said pulse format.

10. The communications system according to claim 9, wherein each transceiver further includes at least one receiver having an input coupled to said RF front end for receiving signals and having an output, a pulse control and correlator having an input coupled to said receiver output for receiving and correlating said signal, and means coupled to said pulse control and correlator for detecting said preamble of said waveform.

11. The communication system according to claim 10, wherein said means coupled to said pulse control and correlator includes a selected data element.

12. The system according to claim 1, wherein said unique waveform includes a series of RF pulse which comprise said transmitted message.

13. A transceiver for receiving a first transmitted signal having a unique pulse pattern, said pulse pattern being a function of time, frequency and phase and for transmitting simultaneously, while receiving, another signal having another unique pulse pattern, said another pulse pattern being a function of time.
frequency and phase, comprising:

front end means which operates to receive a transmitted signal or transmit a signal.
first processor means coupled to said front end means for responding to a first transmitted signal and to monitor said unique pulse pattern as transmitted, second processor means coupled to said front end means for providing another unique signal having a pulse pattern which is a function of time, frequency and phase to enable said pattern to be transmitted while said first transmitted signal is being received; and wherein each pulse pattern has a preamble pulse portion which determines the time frequency for each pulse ins aid pattern, and a tag portion which identified the transmission and the data contained therein.

14. The transceiver according to claim 13 wherein said second processor means includes message and voice buffer means operative to receive data to be transmitted.

15. The transceiver according to claim 13, wherein said front end means includes an antenna for receiving and transmitting signals.

16. The transceiver according to claim 13, wherein each pulse pattern has a preamble pulse portion which determines the time, frequency and phase for each pulse in said pattern, a tag portion which identifies the transmission and the data contained therein.

17. The transceiver according to claim 13, wherein said first processor means includes first means for detecting said preamble and second means for detecting said tag.

18. The transceiver according to claim 13, wherein said second processor means includes first means for forming a preamble and second means for providing a tag position for said transmitted pulse pattern.

19. The transceiver according to claim 13, further including a plurality of processors coupled to said first and second processor means and wherein one or more processors comprising said plurality of processors are selectable by either said first or second processor means for processing signals according to the time, frequency and phase relationships characterizing a pulse being so processed.

20. The transceiver of claim 13, wherein said unique pulse pattern is comprised of a series of RF pulse.