MXPA94008488A - Method and apparatus for bifurcating signal transmission over in-phase and quadrature phase spread spectrum communication channels - Google Patents
Method and apparatus for bifurcating signal transmission over in-phase and quadrature phase spread spectrum communication channelsInfo
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Abstract
An improved system and method for communicating information over in-phase (I) and quadrature phase (Q) communication channels in a spread spectrum communication system is disclosed herein. In an exemplary implementation, first and second information signals are respectively transmitted over the I and Q communication channels using direct sequence spread spectrum communication signals. In-phase pseudorandom noise (PNI) and quadrature phase pseudorandom noise (PNQ) signals of predetermined PN codes are used for spreading the first and second information signals, respectively. In particular, the PNI and PNQ signals are respectively combined with the first and second information signals and an orthogonal function signal to provide I-channel and Q-channel modulation signals. The I-channel and Q-channel modulation signals are used for modulating in-phase (I) and quadrature phase (Q) carrier signals for transmission to a receiver via the I and Q communication channels, respectively. In a preferred implementation the receiver is operative to produce an estimate of at least the first information signal on the basis of the I-channel and Q-channel modulated carrier signals received over the I and Q communication channels. The received I-channel and Q-channel modulated carrier signals are demodulated and despread, with the resultant sequences being correlated into in-phase (I) and quadrature phase (Q) projection signals. A phase rotator operates to provide an estimate of at least the first information signal based on theI and Q projection signals and a received pilot signal.
Description
UNITED STATES PATENT APPLICATION BAR CODE LABEL Serial No. 08 / 146,645 Filing Date: 01 / NOV / 93 Class: 375 Group Technical Unit: 2614 Applicants: EPHRAIM ZEHAVI, SAN DIEGO, CA. ********** CONTINUOUS DATOS ********** VERIFIED ********** FOREIGN APPLICATIONS / PCT ********** VERIFIED Status o Country: CA Drawing Sheet: 8 Total Clauses: 28 Independent Clauses: 6 Registration Fees Received: $ 1,108.00 Attorney File No. QCPA81 Address: RUSELL B. MILLER QUALCOMM INCORPORATED 6455 LUSK BOULEVARD SAN DIEGO, CA 92121 Title: METHOD AND APPLIANCE TO DEFINE THE TRANSMISSION OF
SIGNS ON COMMUNICATION CHANNELS OF DISPERSION SPECTRUM IN PHASE AND PHASE IN QUADRATURE. The present is to certify that it is attached to it a reliable copy taken from the archives of the United States Patent and Trademark Office, of the Request as originally filed, which is identified above. (A wafer seal appears *
Office of Patents and Trademarks) * By authority of the COMMISSIONER OF PATENTS AND TRADEMARKS (signed) Constancia Official Date: DECEMBER 16, 1994.
PATENT APPLICATION SERIAL NUMBER 08/146645 DEPARTMENT OF COMMERCE OF THE UNITED STATES * OFFICE OF PATENTS AND TRADEMARKS QUOTA REGISTRY SHEET
(Seal of the Post Office of the Patent and Trademark Office, dated (illegible)) METHOD AND DEVICE FOR FORKING THE TRANSMISSION OF
SIGNALS IN SPECTRUM COMMUNICATION CHANNELS
OF DISPERSION IN PHASE AND PHASE IN QUADRATURE
BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to communication systems that use dispersion spectrum signals, and more particularly to a novel and improved method and apparatus for communicating information in a broadcast system. dispersion spectrum communication.
9
as -á II. Description of Related Art Communication systems have been developed to allow the transmission of information signals from a source location to a physically different user destination. Both analog and digital methods have been used to transmit these information signals in communication channels linking the source and user locations. Digital methods tend to give several advantages over analog techniques, including for example improved immunity to channel noise and interference, increased capacity and improved communication security through the use of encryption. By transmitting an information signal from a source location on a communication channel, the information signal is first converted into a suitable form for efficient transmission on the channel. The conversion or modulation of the information signal involves varying a
^ parameter of the carrier wave, based on the information signal so that the spectrum of the resulting modulated carrier is confined within the channel bandwidth. At the user location the original message signal is replicated from a modulated carrier version subsequently received for propagation on the channel. This replication is generally achieved using an inverse of the modulation process, used by the source transmitter. The modulation also facilitates multiplexing, ie the simultaneous transmission of several signals in a common channel. The multiplexed communication systems will generally include a plurality of remote subscriber units that require intermittent service of relatively short duration, rather than continuous access to the communication channel. Systems designed to allow communication in a short period of time with a set of subscriber units have been called multiple access communication systems. A particular type of multiple access communication system is known as a dispersion spectrum system. In dispersion spectrum systems, the modulation technique used results in a dispersion of the signal transmitted in a wide frequency band within the communication channel. One type of multiple access dispersion spectrum system is a code division multiple access modulation (CDMA) system. Other multiple access communication system techniques, such as time division multiple access (TDMA), frequency division multiple access (FDMA) and AM modulation scheme such as single-sideband amplitude co primida-expanded, are known in the technique. However, the CDMA dispersion spectrum modulation technique Wk has considerable advantages over these modulation techniques for multiple access communication systems. The use of CDMA techniques in a multiple access communication system is set forth in U.S. Patent No. 4,901,307 issued on February 13, 1990 entitled "MULTIPLE DISPERSION SPECTRUM ACCESS COMMUNICATION SYSTEM USING SATELLITE REPEATERS". OR TERRESTRIAL "assigned to the assignee of this invention. In the aforementioned U.S. Patent No. 4,901,307 there is disclosed a multiple access technique wherein a large number of users of the mobile telephone system each have a transceiver that communicates through satellite repeaters or land base stations using the CDMA dispersion spectrum communication signals. When using CDMA communications, the frequency spectrum can be reused several times thus allowing an increase in user capacity of the
^ system. The use of CDMA results in a much higher spectral efficiency that can be achieved using other multiple access techniques. More particularly, communication in a CDMA system between a pair of locations is achieved by dispersing each transmitted signal over the channel bandwidth using a unique user spreading code. The specific transmitted signals are extracted from the communication channel by dispersing the composite signal energy in the communication channel with the user dispersion code associated with the transmitted signal to be extracted. In particular dispersion spectrum communication systems it has been desired to allow different types of user channels (eg voice data, facsimile or high speed data) to operate at different data rates. These systems have typically been designed to have channels operating at a nominal data rate, and also to reduce the data rate traffic channels in order to provide greater traffic data capacity. However, the increase in traffic capacity by using reduced data rate channels extends the time required for data transmission, and typically requires the use of relatively complex decoders and data encoders. In addition, in some dispersion spectrum communication systems there is also a need to increase the data rate traffic channels by allowing the transmission of data at speeds higher than the nominal ones. Accordingly, an object of the invention is to provide a CDMA dispersion spectrum communication system where the capacity of the traffic channel can increase in the absence of a reduction *
< Í2_ corresponding in the data rate. It is a further object of the invention to provide a CDMA system where the communication channels are available for the transmission of data at speeds higher than those of the nominal system.
SUMMARY OF THE INVENTION The implementation of CDMA techniques in dispersion spectrum communication systems that use
# PN orthogonal code sequences reduce mutual interference between users, thus enabling better capacity and better performance. The present invention provides an improved system and method for communication of information in phase (I) and quadrature (Q) communication channels in a CDMA spread spectrum communication system. In an exemplary embodiment, the first and second information signals are respectively transmitted in I and Q communication channels using direct sequence spread spectrum communication signals. The pseudorandom noise signals in phase (PNj) and pseudorandom quadrature phase noise (PNQ) of the predetermined PN codes are used to disperse the first and second information signals, respectively. In particular, the PNj signal is combined with the first signal of «8? information and an orthogonal function signal for
• providing a channel I modulation signal. Similarly, the PNQ signal is combined with the second information signal and the orthogonal function signal to provide a Q channel modulation signal. Channel I and channel modulation signals Q are used to modulate the phase (I) and quadrature phase (Q) carrier signals for transmission to a receiver via communication channels I and Q, respectively. In the exemplary mode the receiver functions to produce a calculation of at least the first information signal based on the modulated carrier signals of channel I and channel Q, received in the communication channels I and Q. The modulated carrier signals of channel I and channel Q are modulated in intermediate signals received using the orthogonal function signal. In particular, the intermediate received signals are de-correlated using
J ^ a despread signal PN-r in order to provide a first set of phase projection signals (I) and quadrature phase (Q). A phase rotator functions to provide a calculation of the first information signal based on the first set of projection signals I and Q and a received pilot signal.
*
BRIEF DESCRIPTION OF THE DRAWINGS • The features, objects and advantages of the present invention will become more evident from the detailed description that continues, when taken in conjunction with the drawings, in which like numbers identify similar pieces in all the drawings, and where: Figure 1 shows a block diagram of a conventional dispersion spectrum transmitter; > Figure 2 shows a block diagram of a preferred embodiment of a dispersion spectrum transmitter positioned to transmit the information signals of channel I and channel Q according to the invention; Figure 3 provides a more detailed representation of the modulation and dispersion network included within a preferred embodiment of the dispersion spectrum transmitter; Figure 4 illustrates a pilot generation network for providing I and Q channel pilot sequences; Figure 5 shows an exemplary implementation of a built-in RF transmitter within a preferred embodiment of the invention; Figure 6 is a block diagram of an exemplary diversity receiver placed to receive the RF signal energy transmitted over the communication channels I and Q;
Figure 7 is a block diagram of a receiver indicator selected to process the received signal energy over a selected transmission path; and Figure 8 provides a more detailed representation of the selected receiver indicator, illustrated in Figure 7.
DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring to Figure 1, a dispersion spectrum transmitter such as that described in U.S. Patent No. 5,103,459 issued April 7, 1992, entitled "SYSTEM AND METHOD FOR GENERATING FORMS OF SIGNAL WAVES IN A CDMA CELLULAR TELEPHONE SYSTEM ", which is assigned to the assignee of the present invention, and which is incorporated herein by reference. In the transmitter of FIG. 1, the data bits 100 consisting, for example, of speech converted to data by a
# vocoder, are supplied to an encoder 102 wherein the bits are coded convolutionally with the repetition of code symbol according to the input data rate. When the rate or data bit rate is less than the bit processing speed of the encoder 102, the code symbol repetition dictates that the encoder 102 repeats the input data bits 100 in order to create a repetitive data stream. to a
# bit rate that matches the operating speed of the encoder 102. The encoded data is then provided to the interleaver 104 where it is interleaved per block. The interleaved symbol data leaves the interleaver 104 at an exemplary rate of 19.2 ksps at an input of an exclusive gateway 106. In the system of FIG. 1, the interleaved data symbols are mixed to provide greater security in the transmission on the channel. The mixing of the speech channel signals can be achieved by the pseudo-noise (PN) encoding of the interleaved data with a specific PN code for a designated recipient subscriber unit. This PN mix can be provided by the PN 108 generator using a suitable PN sequence or encryption scheme. The PN 108 generator will typically include a long PN generator to produce a unique PN code at a fixed rate of 1.2288 MHz. This PN code is passed through
* then through a decimator, with the resulting mixing sequence of 9.2 MHz being supplied to another input of the exclusive O-gate 106 according to the identification information of the subscriber unit provided thereto. The output of the exclusive O-gate 106 is provided to an input in the exclusive O-gate 110. Referring again to FIG. 1, the other input of the exclusive OR gate 110 is connected to a Walsh code generator 112. The Walsh generator 112 generates a signal corresponding to the Walsh sequence assigned to the channel on which information is being transmitted. The Walsh code provided by the generator 112 is selected from a set of 64 Walsh codes of length 64. The 64 orthogonal codes correspond to Walsh codes from a Hadamard 64 by 64 matrix where a Walsh code is a single row or column of matrix. The mixed symbol data and the Walsh code are passed through the exclusive 0-gate 110 with the result provided as an input to the two 0-exclusive gates 114 and 116. The exclusive O-gate 114 also receives a PN-r signal from the PN-r generator 118, while the other input of the exclusive OR gate 116 receives a PNQ signal from the PNQ generator 118. The PN-r and PNQ signals are pseudorandom noise sequences that typically correspond to a particular area, ie a cell
# covered by the CDMA system and which relates respectively to the communication channels of phase (I) and quadrature phase (Q). The PN-r and PNQ signals are respectively passed through the exclusive O-gate with the output of this exclusive O-gate 110, in order to further disperse the user data before transmission. The code dispersion sequence 122 resulting from channel I and code dispersion sequence 126 of channel Q are used to biphase a pair of quadrature sinusoids. The modulated sinusoids are summed, filtered in band pass, travel at an RF frequency and again filtered and amplified before being radiated by an antenna to complete the transmission on the communication channel. Further details of the use of a pilot signal and of several modulators are described in the above U.S. Patent No. 5,103,459. It is noted that in the transmission system of Figure 1, the same information, i.e. channel data 100, is transported over the communication channel to the nominal channel data rate by the code dispersion sequence of channel I 122 and the code dispersion sequence of the Q channel 126. As described below, the present invention provides a technique for transmitting a pair of information signals other than the nominal rate using the PN-r code and the PNQ code, respectively . When the different information signals are transmitted separately for each pair of communication channels I and Q, the number of channels within the dispersion spectrum system capable of operating at the nominal system data rate is effectively doubled. Alternatively, the given communication channel CDMA can be bifurcated into the independent phase (I) and quadrature (Q) channels. This allows for example that a single information signal be transmitted at double the rated speed by dividing the signal between channels I and Q. In a manner similar to that set forth in U.S. Patent No. 5,103,459, it can be combined a pilot signal with several modulated channel data for transmission. Figure 2 shows a block diagram of a preferred embodiment of a dispersion spectrum transmitter 150 positioned to transmit different channel information signals I 154 and Q channel 156 according to the invention. To facilitate the illustration only a single channel pair is illustrated. It should be understood that in the transmission scheme, the transmitter may include several copies of the circuit as shown in figure 2 for other user channels, in addition to a pilot channel. As described below, the information signals of channel I and channel Q are provided on the communication channels I and Q using the RF carrier signals of the same frequency transmitted in quadrature phase. In an exemplary implementation half of the total number of users of the system receives information exclusively on channel I, while the remaining users receive information exclusively on channel Q. Alternatively, in a high data rate implementation each user receives a signal from channel I and Q channel information modulated by an identical Walsh code. In this way, half of the data comprising a single information signal can be transmitted on each of the channels I and Q, thus allowing the transmission of data at twice the nominal speed. In particular applications the information signals 154 and 156 may consist of, for example, voice converted to a stream of data bits by a vocoder and other digital data. Information signals 154 and 156 which may be individual user channel signals (e.g. User A data and User B data) or a single high-speed data channel signal that is demultiplexed by the demultiplexer 152 into two streams of data. The data streams are then supplied respectively to a pair of coding and interleaving networks 160 and 164. Networks 160 and 164 encode information signals 154 and 156 convolutionally., and interspersed with symbol code repetition according to the input data rate. In the absence of the code symbol repetition, the networks 160 and 164 operate at a nominal speed of, for example 9.6 kbit / s. When the bit rates of input data (for example 4.8 kbit / s) of the information signals are lower than this nominal rate, the bits comprising the information signals 154 and 156 are repeated in order to create a "current". of repetitive data at a rate identical to the nominal symbol rate (for example 9.6 kbit / s). The encoded data is then interleaved and output from networks 160 and 164 as coded and interspersed symbol streams an and bn. The streams of symbols an and bn correspond respectively to convolutionally coded and interleaved versions of the sampled information signals of channel I 154 and channel Q 156, and are supplied to a network of
J ^ modulation and dispersion 170. Network 170 operates to modulate the symbol currents an and bn with a signal supplied by a Walsh generator 174. In the preferred embodiment, the signal provided by the Walsh generator 174 consists of a Walsh code sequence. assigned to the particular pair of communication channels I and Q over which the symbol currents an and bn are transmitted. For an exemplary data rate of 9.6 kbit / s, the Walsh sequence provided by the generator 174 will typically be selected from a set of 64 orthogonal Walsh codes of length 64. In the preferred embodiment the chip rate of the Walsh sequences is selected for In this aspect it is desirable that the chip rate be exactly divisible by the baseband data rate to be used in the system. It is also desirable that the divisor be a power of two. Assuming at least one user channel operating at a nominal baseband data rate of 9600 bits per second results in an exemplary Walsh chip rate of 1.2288 MHz, i.e. 128 x 9600. As indicated in the figure 2, the modulation and dispersion network 170 is further provided with PNj and PNQ dispersion signals by the PN-r and PNQ sequence generators 178 and 180. The PN-r sequence is related to the communication channel I, and is used within the network 170 to disperse the symbol stream an in a channel code scatter sequence I, St. similarly the PNQ sequence is used by the network 170 to disperse the stream of symbols bn before the transmission as a channel code dispersion sequence Q, SQ on the communication channel Q. The channel code dispersion sequences I and Channel Q, St and SQ, are used for the biphase modulation of a quadrature pair of sinusoids generated within an RF transmitter 182. In the RF transmitter 182 the modulated sinusoids will generally be added, filtered in bandpass and shifted of a baseband frequency at the IF frequency, at an RF frequency, and will be amplified at various frequency stages before being radiated by an antenna 184 to complete the transmission on the communication channels I and Q.
Assuming that the transmitter 150 is the iavo of the N transmitters, where i = 1, ... N, the dispersion sequences of channel I and channel Q Sr (i) and SQ (i) produced in this way, can be represented as: SjU) = aníJW.PNj (l) Y, SQ (i) = ^ (ÍJWÍPNQ. (2) where W¿ denotes the Walsh sequence provided by the Walsh generator 174. SP Referring to Figure 3, it is shown a more detailed representation of the modulation and dispersion network 170. Network 170 optionally includes a long PN code sequence generator 184 which operates at a fixed chip rate of 1,228 Mchip / s and a decimator 188 to provide a mixer code at a speed 19.2 ksps instance The PN 184 generator responds to a code selection input to generate the desired code.The PN 184 generator typically provides code length sequences of the order of 242-l chips, although codes of other lengths may be used. Although not necessarily the transmitted information is distinguished on the accompanying communication channels I and Q, the long PN mixing sequences can be used to improve communication security. In the case where high speed data will be transmitted to a single user on the two I and Q channels, the same PN code sequence is used. However, in the case where the I and Q channels are assigned to different users, the long PN mixing codes are preferably different, for example either different code sequences are used or the same sequence is used. of code but with different deviations of code phase (a delayed or advanced code sequence). The PN 184 generator is capable of producing these code sequences as is well known inTHE.
# The technique. In the case of multiple access where multiple copies of the circuits of Figure 3 are implemented, the mixing codes that are assigned to each of the user channels are different, either by different codes but preferably from the same code but of different deviation of code phase. O-Exclusive 186 and 190 gates can be used to use unique mixing codes
/ < & produced by the long PN generator 184 and provided by the decimator 188 to mix the symbol currents an and bn before sending them to a channel I power control and the timing circuit 192, and to a Q channel power control and a timing circuit 196. Circuits 192 and 196 allow control over signal transmissions from users of I and Q communication channels to be exerted by multiplexing power control and ft timing information bits in power currents. symbol an and bn. The multiplexed symbol streams produced by channel I and channel Q timing and power control circuits 192 and 196 are provided to inputs of the O-exclusive combiners 202 and 204, respectively. As shown in Figure 3, the other inputs of the O-exclusive combiners 202 and 204 are provided with a signal corresponding to the Walsh sequence.
^ preassigned generated by the Walsh generator 174. The symbol currents from the channels of channel I and channel Q 192 and 196 are passed through gate 0-exclusive with the Walsh sequence through the exclusive gates 0- 202 and 204, with the resulting bit streams respectively being provided as inputs to the exclusive O-gates 208 and 210. The exclusive O-gate 210 also receives the signal PNj, while the remaining input of the exclusive-OR gate 208 receives the signal PNQ. The signals PN-r and PNQ are passed respectively to O-exclusive gates with the output of the exclusive O-gates 202 and 204, and are provided as inputs to the baseband filters of channel I and channel Q, 214 and 216 In an exemplary embodiment the baseband filters 214 and 216 are designed to have a normalized frequency response S (f) confined to between ± d1 in the passband 0 < f < fp, and that is less than or equal to -d2 e the stop band f > fs. In the exemplary mode d? = 1.5 dB, d2 = 40 dB, fp = 590 kHz, and fs = 740 kHz. As indicated by FIG. 3, the baseband filters 214 and 216 produce the dispersion sequences of channel I and channel Q, S, and SQ. The filtered signals from the channel I and Q channel baseband filters 214 and 216 are provided to the RF transmitter 182. In the preferred embodiment, a pilot channel that does not contain data modulation is transmitted together with the I channel spread sequences. and channel Q, Sr and S-. The pilot channel can be characterized as an unmodulated spread spectrum signal used for signal acquisition and tracking purposes. In systems incorporating a plurality of transmitters according to the invention, the set of communication channels provided will each be identified by a single pilot signal. However, instead of using a separate set of PN generators for the pilot signals, it is observed that a more efficient approach to generating a set of pilot signals is to use offsets in the same basic sequence. Using this technique, a target receiver unit sequentially searches for the complete pilot sequence and is tuned to the deviation or displacement that produces the strongest correlation. Consequently, the pilot sequence preferably will be long enough so that many different sequences can be generated by displacements in the
• basic sequence in order to support a large number of pilot signals in the system. In addition, the separation or displacement must be large enough to ensure that there is no interference in the pilot signals. Thus, in an exemplary embodiment the pilot sequence length is selected to be 215, which allows 512 pilot signals with deviations in a 64 chip base sequence. Referring to Figure 4, a pilot generation network 230 includes a Walsh generator 240 to provide the "zero" Walsh sequence W0 consisting of all zeros to the O-exclusive gates 244 and 246. The Walsh W0 sequence is multiplied by the sequences PN-r and PNQ that use the O-exclusive gates 244 and 246, respectively. Since the sequence W0 includes only zeros, the information content of the resulting sequences depends only on the PNj and PNQ sequences. Therefore in an alternative mode the exclusive 0- # gates 244 and 246 need not be present with the PN-r and PNQ sequences as long as the sequences produced by the exclusive 0- gates 244 and 246 are directly provided as inputs to the Finite Impulse Response Filters (FIR) 250 and 252. The output of the filtered sequences of the FIR filters 250 and 252, correspond respectively to the pilot sequences of channel á, <; 5? ßt. I and channel Q Pt and PQ, and are supplied to RF transmitter 182. It should be noted that since the sequence W0 includes only zeros as previously mentioned in an alternative embodiment the O-exclusive combiners 244 and 246 need not be present with the PN sequences -r and PNQ provided directly to the FIR filters 250 and 252. Referring to FIG. 5, an exemplary implementation of the RF transmitter 182 is shown. The transmitter 182 includes a channel aggregate I 270 to sum
To the PN-r Sti scattering data signals, 1. = 1 to N, with the channel I P pilot. Similarly, the Q-channel adder 272 serves to combine the scatter data signals PNQ, SQi, i = 1 to N, with the Q-channel pilot, PQ. The digital-to-analog (D / A) converters 274 and 276 are provided to convert the digital information of the I-channel adders and Q-channel 270 and 272, respectively, in analog form. The analog waveforms produced by the D / A converters 274 and 276 are provided together with the carrier frequency signals of the local oscillator (LO) Cos (2pft) and Sen (2pft), respectively, to the mixers 288 and 290 where they are mixed and provided to the adder 292. The quadrature phase carrier signals Sen (2pft) and Cos (2pft) are provided from frequency sources (not shown). These mixed IF signals are summed in adder 292 and are provided to mixer 294.
IB The mixer 294 mixes the summed signal with an RF frequency signal from the frequency synthesizer 296 in order to provide upward conversion of the frequency to the RF frequency band. The RF signal includes in-phase (I) and quadrature (Q) / Y-phase components are filtered in bandpass by band pass filter 298 and output to RF amplifier 299. Amplifier 299 amplifies the limited signal in band according to an input gain control signal to > starting from the transmission power control circuitry (not shown). It should be understood that different implementations of the RF transmitter 182 may employ a variety of addition, mixing, filtering and signal amplification techniques that are not described here, but are well known in the art. Table I below establishes in a summary form the values of the modulation parameters that correspond
F to the data transmission in the exemplary speeds of 1.2, 2.4, 4.8, 9.6 and 19.2 kbps.
TABLE I
-Jr Figure 6 is a block diagram of an exemplary diversity receiver placed to receive the RF signal provided by the RF transmitter 182. In Figure 6 the transmitted RF signal is received by the antenna 310 and provided to a diversity receiver. RAKE which is comprised of the analog receiver 312 and the digital receiver 314. The signal in the form received by the antenna 310 is provided to the analog receiver 312 and may be comprised of multiple path propagations of the same pilot signals and data intended for receivers of individual subscriber or multiple subscribers. The analog receiver 312, which is configured in the exemplary mode as a QPSK modem, downconverts the frequency and digitizes the received signal into the composite I and Q components. The composite I and Q components are provided to digital receiver 314 for demodulation. The demodulated data is then provided to the digital circuitry 316 for combining, deinterleaving and decoding. Each component I and Q leaves the analog receiver 312 and may be comprised of multiple path propagations of an identical pilot signal and corresponding data signals. At the digital receiver 314 some multi-path propagations of the transmitted signal, as selected by a searcher receiver 315 HA in combination with a controller 318, are each processed by a different receiver from the various data receivers or demodulators 320a-320c , which are also referred to as "indicators". Although only three data demodulation indicators (demodulators 320a-320c) are illustrated in Figure 6, it should be understood that more or fewer indicators may be used. Of the composite I and Q components, each indicator extracts, by means of the de-dispersion, the I and Q, R1 and RQ components of the pilot signals and the data signals corresponding to the selected path. The I and Q components of the pilot signal for each indicator can be said to form a pilot vector, and the I and Q components of the I channel data and the Q channel data are said to form a pair of data vectors. According to the invention, these I and Q components of the pilot and data vectors are extracted from the received signal energy in order to produce calculations of the I channel and Q channel data. The pilot signal is typically transmitted to a force of signal greater than the data signals, and as such the magnitude of the pilot signal vector is greater than the received data signal vectors. Accordingly, the pilot signal vector can be used as a precise phase reference for signal processing. In the transmission process, the pilot and data signals as they are transmitted travel in the same path to the receiver. However, due to channel noise the received signal will generally deviate from the transmitted phase angle. The point formulation, ie scalar, products of the pilot signal vector with the data signal vectors of channel I and channel Q, are used as set forth here to extract the data of channel I and channel Q from the signal received by the selected receiver indicator. In particular, the point product is used to find the magnitudes of the components of the data vectors that are in phase with the pilot vector, projecting the pilot vectors on each of the data vectors. A method for extracting the pilot signal from the signal energy received by the selected receiver indicator is described below in relation to FIG. 8, and also in copending United States Patent Application Serial No. 07 / 981,034, filed on November 24, 1992, entitled "PRODUCT CIRCUIT PUNTO DE PORTADOR PILOTO" which is assigned to the assignee of this invention and which is incorporated herein by reference. As noted above, in an exemplary implementation each user is assigned with a set of 64 VIL orthogonal Walsh codes of length 64. This allows a set of channels including a pilot channel, 63 e? I channels, and 63 Q channels, are transmitted using a given pair of PN? and PNQ dispersion sequences. The transmitted signal energy associated with this total complement of channels can be expressed as:
S (t) =? cos (? 0t) - Q sin (? 0t); (3) where 63? = S an i iJ WiPNj. (4) i = 0
bnfiJWiPNQ (5) 0 It follows that the signal R (t) received on the kava transmission path by the analog receiver 312 is given by:
Rk (t) =? cos (? 0t +?) - Q sin (? 0t +?) + n (t) (6) where the transmitted signal has a random phase shift of? in relation to the local reference of the receiver, and where n (t) denotes the signal interference interference inherent within the signal Rk (t). The signal Rk (t) is passed through a bandpass filter within the analog receiver 312 having a baseband pulse response h (-t), where h (t) denotes the pulse response of the baseband filter within the transmitter 182. The filtered signals are shown at times t = nTw, where Tw denotes the period between successive chips in the assigned Walsh code sequence W¿. These operations produce the projections I and Q, R and Rk, where: i Q Rk = Rk (t) eos (? 0t) * h (t) I t = nTw (7)
Rk = -Rk (t) sin (? 0t) * h (t) I t = nTw (8)
Using equation (6), the sampled projections R j (nTw and RQ (nTw) are given by: f Rk (nTw) =? Cos? - Q sin? + N ± (9)
Rk (nTw) = í sen? + Q cos? + Nq (10)
where the noise terms Ni and N_ can be characterized as random processes of zero mean and variance s2. Of the
sampled projections Rk (nTM) and Rk (nTM) by the receiver indicator i Q selected to receive the signals transmitted on the kava transmission path. Referring to Figure 7, a block diagram of one of the receiver indicators 320 (Figure 6) selected to process the sampled projections R (nTw) and Rk (nTw) produced by the analog receiver 312 is displayed. The receiver indicator 320 includes a demodulation / dispersion and phase rotation circuit 340, as well as a phase calculation and time tracking circuit 344. As described in more detail below, circuit 340 functions to demodulate the sampled projections Rk (nTw) and RQ (nT? W) using the Walsh code sequence assigned Wi ..
After demodulation the resulting bitstream is de-dispersed using the PN-r and PNQ sequences and is provided to a set of correlators. The correlators function to produce intermediate projections of phase and phase quadrature of the data transmitted on the communication channels I and Q. The data calculations ak and bk are then generated by rotating nn the phase of the intermediate projections of the transmitted data according to a calculated phase shift? between the transmitted waveform and the locally generated reference of the receiver 314. Will the phase calculation and the time tracking circuit 344 typically include a phase locked loop or other suitable circuit to generate the phase estimate? . In a preferred embodiment, the phase estimation and time tracking circuit 344 functions to provide a calculation of the pilot signal transmitted on the kava path based on the intermediate signals produced by the circuit 340 during demodulation and de¬
• dispersion of the sampled projections Rk (nTw) and Rk (nTw). The extracted pilot signal is used for the phase rotation operation developed by the circuit 340, as well as for the time alignment within a symbol combiner (not shown), to which the ak and b calculations of the transmitted data are provided. and b. Within the n n n n symbol combiner the calculations of the data transmitted on each trajectory are aligned in time and fw is added together, thus improving the signal to noise ratio. Figure 8 provides a more detailed representation of the receiver indicator 320 illustrated in the figure
7. As shown in Figure 8, the circuit 340 includes multipliers 380 and 382, to which the sampled projections Rk (nTw) and Rk (nTw) are supplied at the PN dispersion rate of 1.2288 MHz. In the exemplary embodiment the logical values high and low of the binary sequences supplied to each of the multipliers shown in
# Figure 8, add up to be +1 and -1, respectively. A Walsh 386 generator is connected to the two multipliers
380 and 382, where its output (V¡L) is multiplied with the projections R (nTM) and Rk (nT "). The circuit 340 includes i Q in addition to the PN 390 and 392 generators to provide the PN-r sequence to the multipliers 398 and 400, and the PNQ sequence to the multipliers 402 and 404. As indicated by the z. Figure 8, the Walsh demodulated projections R, k (nTw) of the multipliers 380 are multiplied with the PN-r sequence in the multipliers 398 and with the PNQ sequence in the multiplier 402. Similarly, the demodulated Walsh projections R, ( nT?) leave the multiplier 382 and Q multiply with the sequence PNj in the multiplier 400, and with the sequence PNQ in the multiplier 404. The multipliers 398 and 400 are correlated with the demodulated projections Walsh R | k (nT?) and R, k (nT?) With the QF sequence PN-r. The proper synchronization is maintained between the PN JT sequence. and the sequences R | jk (nT "W) and R | kQ (nT? W) by an alignment circuit in time 410, the operation of which is discussed below. Similarly, the sequences R, (nTw) and R, k (nTw) are correlated with the PNQ sequence by multipliers 402 and 404. The correlated outputs of the multipliers 398 and 400 are provided to the corresponding accumulators of the
F channel I 414 and 416, with the correlated outputs of the multipliers 402 and 404 provided to the corresponding accumulators of channel Q 418 and 420. The accumulators 414, 416, 418 and 420 accumulate the input information over a Walsh symbol period, Tw, which in the exemplary mode is about 64 chips. The outputs of the accumulator are provided to the delay elements 424, 426, 428 and 430 through corresponding switches 434, 436, 438 and 440 under the control of the timing alignment circuit.
# 410. The outputs of the channel accumulators I 414 and 416, denoted respectively as It and Ig, can be expressed as: L I r (nT = S Rj ULn + j J T iPNj j = l
+ nL (11)
= l L = Lan (i) sen? + S cos? WjPN-r + n (12) j = l where the noise terms n. ^ And nq are independent random variables with a mean of zero and a variance Ls2, and where the assigned Walsh code is assumed to have a length of L Walsh chips. Similarly, the Qt and QQ outputs of the Q 428 and 430 channel accumulators are provided by: L Qj (nTw) = S RgULn + jJT WiPNQ j = l L = Lbn (i) cos? + S? sen? WJPNQ + nL (13) j = l L QQ (nTw) = - S R-r ULn + j J T WiPNg
L = Lbn (i) sin? - S? cos? W ^ NQ + nq (14) j = l Referring again to FIG. 8, the time tracking and phase estimation circuit 344 includes a pilot station circuit 450 to produce pilot phase signals used to maintain alignment in time within the receiver indicator 320. The pilot extraction circuit 450 includes an adder 454 to which the outputs of the multipliers 398 and 404 are provided, as well as an adder 456 for multiplying the outputs of the multipliers 400 and 402. The circuit 450 includes in addition to the Walsh generators 462 and 464 which function to supply the Walsh W¿ and W0 sequences, respectively, to a multiplier 466. The resulting demodulating sequence W ^ Q produced by the multipliers 466, aligned in time appropriately thanks to the timing information provided by circuit 410 to Walsh generators 462 and 464, is provided to multiplier 468 and 470. The sequence W.W0 is supplied with the output of the adder 454 by the multiplier 468, while the multiplier 470 performs the same operation in response to the sequence V¡LVI0 and the output provided by the adder 456.
The multiplier outputs 468 and 470 are respectively accumulated by the pilot extraction accumulators 474 and 478 over a selected range to ensure the generation of a non-deviated phase calculation of the received pilot signal. In an exemplary embodiment the accumulation interval expands to a period of time of duration 2rL, where as previously mentioned L corresponds to the Walsh symbol period. This accumulation interval will generally be carried out for periods of length "rL" that occur immediately before and after the time in which the pilot phase is to be calculated. The timing alignment between the outputs produced by the accumulators 414, 416, 418 and 420 and the outputs of the pilot extraction accumulators 474 and 480, is maintained by the delay elements 424, 426, 428 and 430. The signal delay performed by each of the delay elements 424, 426, 428 and 430 is selected to be of a duration equivalent to the range expanded by "r" future Walsh symbols. Consequently, when generating the pilot calculations corresponding to the transmitted symbols, an and bn, a set of data samples Sj accumulate where L (n-r) + 1 <; j < L (n + r), through the accumulators 474 and 478. Therefore the switches 482 and 486 are operated to the closed position at a frequency of 1 / LTW, while the switches 434, 436, 438 and 440 are operated to be closed at a frequency of 1 / LTW. The signals produced by the pilot extraction accumulators 482 and 486 correspond to the channel I and Q channel projections of the pilot signal (Pk) transmitted on the kva path and can respectively be represented as: Lr Pk • COS (T) = SS. { RJPNJWQ + RQPNQWQ} (15) n = -Lr
. { -RJPNQWQ + RQPNJWQ} (16) -Lr Referring to FIG. 8, the channel I and channel Q projections of the pilot signal are each provided to the channel phase rotator I 550 and the Q 552 channel phase rotator. channel phase I 550 produces a sequence of output data values a corresponding to a calculation of the data sequence a (i)
ñal
Pilot Pk. The specific operation developed by the I 550 channel phase rotator can be represented as:
ak (i) = II • Pk • cos (? + IQ • Pk • sin (?) (17) 1 where equation (18) is obtained from equation (17) using trigonometric identities:?? A Pk • ( cos (?) • cos (?) + sin (?) • sin (?)) = Pk • cos (? -?) (19)
-?) When inspecting equation (18) it is revealed that A when the phase error a = (? -?) Between the displacement of A real phase? and the estimated phase? is zero, the values of data A of output ak can be expressed as: n a (i) = L • Pk • an (i) (21) n values (i) weighted in proportion to the strength of the transmitted pilot signal. The relative forces of the pilot signals transmitted on the different received transmission paths are used to optimize the signal to noise ratio when the symbols are combined for each receiver indicator 320. As indicated by equation (15), the presence J of the error of phase a allows unwanted cross-product interference from the signal energy of the Q-channel to undesirably reduce the value of ak (i). This effect is diminished since the PN dispersion attenuates the average power of the cross product interference, as represented by the second term of equation (18), by a factor of L in relation to the first term. The term noise n 'can be characterized as a random variable that has an average of zero and a variance L Ps2. fß The operation of the channel phase rotator Q 552 can be similarly represented by the following expression:
bk (i) = Qi • Pk • eos (?) + QQ • Pk • sin (?) (22)
bk (i) = L • Pk • bn (i) cos (? -?) - Pk • sin (? -?)? T JP13N1 * Q + n '= l (23) where the term noise n "is a random variable that has a mean of zero and a variance L P2 s2.
# k when the phase error a = (? -?) between the real phase shift of? and the calculated phase? is zero, the output data values b (i) can be expressed as:
bk (i) = L • Pk • an (i) (24) n As noted above, the weighted calculations ak (i) and bk (i) of the transmitted channel I and channel Q data nn on the kva path combine with the
outputs to (i) and b (i) of the remaining receiver indicators n n by a symbol combiner (not shown), but contained within the digital circuitry 316 of the figure
6. As only one of the symbol streams a or bk n n is addressed to the particular user, any I channel or Q channel, only one of the symbol streams needs to be processed. In a digital circuitry 316 of exemplary implementation a multiplexer or switch is included which in response to a selection signal provides a selected output of one of the two symbol streams. The digital circuitry 316 also contains the demixing circuitry which includes a PN generator and a decimator. The mixed symbol stream is de-mixed upon removal of the decimated PN code sequence, with the result that the symbols are deinterleaved within a deinterleaver contained within the digital circuitry 316. The deinterleaved symbol stream is then decoded by a decoder inside. of a digital circuitry 316 and provided to the user as user data. In an alternative implementation in the case of different users, the channel data both I and Q can be processed separately (demixed, deinterleaved and f decoded) with the output of the desired user data provided through a device such as a multiplexer or switch . Other arrangements can be easily implemented as a hybrid between a single path processing and a dual path processing, depending on the placement of the multiplexer in the processing path. In the case of using the I and Q channels for different users, the BPSK type modulation is used to transmit the data to each user. However, as in an exemplary implementation half of the total number of users are using channel I and the remaining users channel Q, the entire system can be observed by performing the QPSK modulation and the QPSK dispersion. However, for the high data rate of a single user, the user uses the two I and Q channels, the processing for the two channels must be provided if
JJL will use this feature of high-speed data communication. In the case of a high-speed data user, the data is multiplexed, processed and transmitted on the two channels, that is, half of the data is provided as an information signal on each of the I and Q channels to allow data transmission to be twice the nominal speed. Upon receipt, each data demodulator 320 (Figure 6) provides calculations
• weighted ak (i) and bk (i) of channel I and channel Q nn data transmitted on the kava path that are respectively combined with outputs ak (i) and b (i) of the remaining nn receiver indicators by combiners symbol an and bn (not shown), but contained within the digital circuitry 316 of Figure 6. In an exemplary implementation the digital circuitry 316 processes the two symbol streams independently with the resulting combined data from the output to the user. The digital circuitry 316 contains demixing circuitry that includes a PN generator and a decimator. The mixed symbol stream is de-mixed by eliminating the decimated PN code sequence of the two symbol streams. The resulting symbols are de-interleaved into separate deinterleavers contained within digital circuitry 316. The deinterleaved symbol streams are decoded by separate decoders within the digital circuitry 316. The decoded data streams are then combined into a single data stream by a multiplexer inside. of the digital circuitry 316 and are provided to the user as user data. Other implementations can be easily derived from the above for data processing. The previous description of the preferred modalities
Claims (16)
- mF is provided to allow any person skilled in the art to make or use the present invention. Various modifications of these modalities will become readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other modalities without the use of the inventive faculty. In this way, the present is not intended to be limited to the modalities shown here, but must be in accordance with the broad scope corresponding to the principles and novel features set forth herein. CLAIMS; A system for modulating a first and a second information signal for transmission in a dispersion spectrum communication system, comprising: means for generating pseudorandom noise signals in phase (PN-r) and pseudorandom phase noise in quadrature (PNQ) of predetermined PN codes; means for generating an orthogonal function signal; means for combining the PNj signal with the first information signal and the orthogonal function signal for providing a modulation signal I and for combining the PNQ signal with the second information signal and the orthogonal function signal for providing a Q modulation signal; and means for modulating the phase (I) and quadrature phase (Q) carrier signals of a predefined phase relationship with the modulation signals I and Q, respectively. The system according to claim 1, wherein the means for combining includes means for biphase modulation of the first information signal with the signal PN? and for biphase modulation of the second information signal with the PNQ signal. The system according to claim 1, wherein the means for generating an orthogonal function signal includes means for selecting an orthogonal function from a set of orthogonal Walsh functions, and a means for deriving the orthogonal function signal based on the orthogonal function selected. 4. A system for modulating an information signal to be transmitted over channels in phase (I) # and quadrature phase (Q) of a dispersion spectrum communication system using a carrier signal and a replica of the carrier signal in quadrature phase with it, comprising: means for dividing the information signal into a first and second portions for transmission to one or more container users destined on the I and Q channels; means for generating an orthogonal function signal; means for generating random phase noise signals (PN-r) and quadrature phase random noise (PNQ) of the predetermined PN codes; means for combining the PN-r signal with the first portion of the information signal and the orthogonal function signal for providing a modulation signal I, and for combining the PNQ signal with the second portion of the information signal and the signal of orthogonal function in order to provide a Q modulation signal; and means for modulating the carrier signal and the replication of the carrier signal with the modulation signals I and Q, respectively. 5. The system according to claim 4, further including means for adding a timing control signal to the information signal, the timing control signal is indicative of the signal propagation delay on the I and Q channels of the signaling system. communication. The system according to claim 4, wherein the combining means includes means for biphase modulation of the modulation signal I with the signal PN-r, and for the biphase modulation of the modulation signal Q with the signal PNQ. 7. A code division multiple access communication system for providing phase dispersion spectrum (I) and quadrature phase (Q) communication channels over which first and second information signals are transmitted, comprising: means for generating pseudorandom noise signals in phase (PNj) and quadrature phase pseudorandom noise (PNQ) signals of predetermined PN codes; means for generating an orthogonal function signal; means for combining the PN-r signal with the first information signal and the orthogonal function signal to provide a modulation signal I, and for combining the PNQ signal with the second information signal and the orthogonal function signal to provide a signal modulation Q; means for modulating the phase (I) and quadrature phase (Q) carrier signals of a predetermined phase relationship with the modulation signals I and Q, and for transmitting the carrier signals I and Q on the communication channels I and Q, respectively; and receiving means for producing a calculation of at least the first information signal according to the modulated carrier signals I and Q received on the communication channels I and Q. The communication system according to claim 7, wherein the The receiver means further includes means for demodulating the modulated carrier signals I and Q received on the communication channels I and Q towards intermediate received signals using the orthogonal function signal. The communication system according to claim 8, wherein the receiving means further includes: means for generating a first de-dispersion signal by replicating the PN-r signal, and first means for correlating the intermediate received signals using the F first despread signal in order to provide a first set of phase (I) and quadrature phase (Q) projection signals. The communication system according to claim 7, further including: means for combining the orthogonal function signal with a pilot signal in order to provide a modulated pilot signal; F means for transmitting the modulated pilot signal on a pilot channel. The communication system according to claim 10, wherein the receiving means further includes: means for producing a calculation of the pilot carrier signal by demodulation, using the orthogonal function signal, the modulated pilot signal transmitted on the pilot channel; and a first phase rotation means for generating the calculation of the information signal based on the first set of projections I and Q and the calculation of the pilot carrier signal. The communication system according to claim 11, wherein the receiving means further includes: means for generating a second dispersion signal by replication of the PNQ signal, and second means for correlating the intermediate received signals using the second distress signal. - Dispersion in order to provide a second set of phase (I) and quadrature phase (Q) projection signals. The communication system according to claim 12, wherein the receiving means further includes a second phase rotation means for generating a calculation of the second information signal based on the second set of the I and Q projections and the calculation of the transmitted pilot carrier signal. The communication system according to claim 11, wherein the receiving means further includes means for delaying the first set of projection signals I and Q. 15. A method for transmitting first and second information signals in a dispersion spectrum communication system comprising the steps of: generating pseudorandom noise signals in phase (PNj) and quadrature phase pseudo-random noise ( PNQ) of predetermined PN codes; generate an orthogonal function signal; combining the PN-r signal with the first information signal and the orthogonal function signal to provide a modulation signal I, and combining the PNQ signal with the second information signal and the orthogonal function signal to provide a Q modulation signal; and modulating the in-phase (I) and quadrature phase (Q) carrier signals of a predefined phase relationship with the modulation signals I and Q respectively. 16. The method according to claim 15, further comprising the steps of: modulating the modulation signal I with the PNX signal in biphase, and modulating the Q modulation signal with the PNQ signal biphase. 17. The method according to claim 16, wherein the step of generating an orthogonal function signal includes the steps of selecting an orthogonal function from a set of orthogonal Walsh functions., and derive the orthogonal function signal based on the selected orthogonal function. The method according to claim 17, further including the step of transmitting the modulated flB carrier signals I and Q over the communication channels I and Q, respectively. 19. A method for modulating an information signal to be transmitted on the phase (I) and quadrature phase (Q) channels of a dispersion spectrum communication system is used a carrier signal and a replica of the carrier signal in quadrature phase with it, comprising: dividing the information signal into first and second portions for transmission to one or more recipient users destined on channels I and Q; generate an orthogonal function signal; generate pseudorandom noise signals in phase (PN-r) and pseudorandom quadrature phase noise (PNQ) of the predetermined PN codes; combining the PN-r signal with the first portion of the information signal and the orthogonal function signal for 4 providing a modulation signal I, and combining the PNg signal with the second portion of the information signal and the orthogonal function signal to provide a Q modulation signal; and modulating the carrier signal and the replication of the carrier signal with the I and Q modulation signals, respectively. The method according to claim 19, further comprising the step of adding the timing control signal to the information signal, the timing control signal being indicative of the signal propagation delay on the I and Q channels. of the communication system. The method according to claim 20, further including the step of biphase modulation of the modulation signal I with the signal PNj, and the step of the biphase modulation of the Q-modulation signal with the PNQ signal. 22. In a code division multiple access (CDMA) communication system, a method for providing phase dispersion (I) and quadrature phase (Q) spectrum communication channels over which are transmitted first and second information signals, the method comprising the steps of: generating pseudorandom noise signals in phase (PN-r) and quadrature-phase pseudo-random noise (PNQ) k of predetermined PN codes; generate an orthogonal function signal; combining the PN-r signal with the first information signal and the orthogonal function signal to provide a modulation signal I, and combining the PNQ signal with the second information signal and the orthogonal function signal to provide a Q modulation signal; modulate the carrier signals of in phase (I) and of < = mf quadrature phase (Q) of a predefined phase relationship with the modulation signals I and Q; transmitting the carrier signals I and Q over the communication channels I and Q, respectively; and producing a calculation of the at least first information signal according to the modulated carrier signals I and Q received on the communication channels I and Q. j ,. 23. The method according to claim 22, which ^ r further includes the step of demodulating the modulated carrier signals I and Q received on the communication channels I and Q towards intermediate received signals using the orthogonal function signal. The method according to claim 23, further including the steps of: generating a first despread signal by replicating the signal PN-r, and jft correlating the intermediate received signals using the first despread signal in order to provide a first set of in-phase (I) and quadrature (Q) projection signals. The method according to claim 22, further including the steps of: combining the orthogonal function signal with a pilot signal in order to provide a modulated ß pilot signal, and transmitting the modulated pilot signal on a pilot channel. 26. The method according to claim 25, further including the steps of: demodulating the modulated pilot signal transmitted over the pilot channel; produce a calculation of the pilot signal transmitted on the pilot channel; and ^ F generating the calculation of the first information signal based on the first set of the I and Q projections and the calculations of the pilot carrier signal. The method according to claim 26, further including the steps of: generating a second de-dispersion signal by replicating the PNQ signal, and correlating the intermediate received signals jflt using the second de-dispersion signal in order to provide a second set of projection signals in phase (I) and quadrature phase (Q). The method according to claim 27, further including the step of generating a calculation of the second information signal based on the second set of projections I and Q, and the calculation of the transmitted pilot carrier signal. SUMMARY OF THE INVENTION An improved system and method for communicating information in communication channels in phase (I) and quadrature phase (Q) in a dispersion spectrum communication system is disclosed. In an exemplary implementation, first and second information signals are respectively transmitted in the I and Q communication channels using direct sequence spread spectrum communication signals. The pseudorandom noise signals in * phase (PN-r) and quadrature phase pseudorandom noise (PNQ) signals of the predetermined PN codes are used to disperse the first and second information signals, respectively. In particular, the PN-r and PNQ signals are respectively combined with the first and second information signals and an orthogonal function signal to provide modulation signals of channel I and channel Q. The modulation signals of channel I and channel Q are they use to modulate the phase (I) and quadrature phase (Q) carrier signals for transmission to a receiver via I and Q communication channels, respectively. In a preferred implementation, the receiver functions to produce a calculation of at least the first information signal based on the modulated carrier signals of channel I and channel Q received in the communication channels I and Q. The modulated carrier signals of the channels I and Q channel are demodulated • 55 and they disperse, with the resulting sequences remaining correlated in phase (I) and quadrature (Q) projection signals. A phase rotator functions to provide a calculation of at least the first information signal based on the I and Q projection signals and a received pilot signal. COMBINED DECLARATION WITH POWER ATTORNEY'S FILE No. QCPA81 # AS INVENTOR APPOINTED BELOW, THROUGH THIS I DECLARE THAT: This Statement is of the following type: Original Supplemental Continuation in Divisional Part Continuation National Stage of PCT My residence, postal address and citizenship are as indicated below next to my name: I believe to be the original inventor, first and only (if only one name is named below) or an original, first and joint inventor (if more than one name is named below) of the claimed invention and for which a patent is sought for the invention entitled: METHOD AND DEVICE FOR FORKING THE TRANSMISSION OF SIGNALS IN COMMUNICATION CHANNELS OF DISPERSION SPECTRUM IN PHASE AND PHASE IN QUADRATURE, the specification of which: 56 X Attached to this X It was filed on October 28, 1993 as application Serial No. 08/14902 _ It was amended on (if applicable). _ Described and claimed in the PCT International Application No. filed and amended under Article 19 PCT the. By this I declare that I have reviewed and understood the content of the identified specification # above, including claims, as amended by any amendment referred to above. I acknowledge the duty to disclose information that is material for the examination of this application in accordance with title 37, Code of Federal Regulations, section 1.56 (a). Through the present claim the benefit of foreign priority under Title 35, Code of the States * United section 119 of any foreign application (s) for a patent or inventor's certificate or any PCT International application (s) designating at least one country other than the United States of America listed below, and I have also identified below any foreign application (s) for a patent or an inventor's certificate or any PCT International application (s) designating at least one country other than the United States of America submitted by me on the same invention that has a previous filing date to that of the application (s) of the one on which the priority is claimed: (Country) (Application No.) (Day / Month / Year / filed) Priority Claimed Yes _ NO Through this claim the benefit under Title 35 , United States Code Section 120 of the application (s) of the United States listed below and, in relation to the subject matter of each of the claims of this application which is not disclosed in the above United States patent application in the manner provided for in the first paragraph of Title 35, United States Code, Section 112, I acknowledge the duty of disclosure of substantial information as defined in Title 37, of the Code of Federal Regulations, Section 1.56 (a), which occurred between the filing date of the previous application and the date of the International filing of the PCT or National, of this application: (Serial No.) (Submission Date) (State) By means of this I indicate as my attorneys and / or agents to process this application and manage all matters related to it in the United States Patent and Trademark Office. : Russell B. -? \ *** 58 Miller, Registration No. 31,122 and / or Katherine W. Walker, Registration No. P-37,470. Please direct all telephone calls to Russell B. Miller at (619) 658 4833 and direct all correspondence to: Russell B. Miller, QUALCOMM '"Incorporated, 6455 Lusk Boulevard, San Diego, California 92121. I hereby declare that all statements made here of my own knowledge are true and that all statements made based on information and belief are true, and further that these statements were made with the knowledge that voluntary false statements and the like so made are punishable with fine or imprisonment, or both, under Section 1001 of Title 18 of the United States Code, and such false voluntary statements may compromise the validity of the application or of any patent granted thereon. : Ephraim Zehavi Inventor's Signature: (signed) Date: Residence: 5365 Toscana Way, San Diego, California 92122 Ciu Dacianity: Israel Postal Address: 5365 Toscana Way, San Diego, California 92122.
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