Data burst randomizer
First Claim
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1. A spread spectrum modulator for modulating variable rate digital data generated in data frames of a predetermined time duration with each frame of data having a number of data bits which is a predetermined multiple of data bits in a frame of a least number of data bits, comprising:
- encoder means for receiving and convolutionally encoding a frame of variable rate digital data, and generating a frame of symbol data with said symbol data in a first ordered sequence;
interleaver means for reordering said symbol data in said frame and generating said frame of symbol data in a second ordered sequence, and if said frame of symbol data corresponds to a frame of variable rate digital data having a number of data bits less than a frame maximum of data bits said interleaver means generating said symbol data and a predetermined number of repeats of said symbol data in said frame of symbol data in said second ordered sequence to generate a predetermined frame maximum number of symbols in said frame of sequence symbol data in said second ordered sequence;
symbol encoder means for determining from a value of each one of consecutive portions of said frame of symbol data in said second ordered sequence an modulation symbol of a set of modulation symbols, and generating an output frame of function data;
first spreading means for generating a first pseudorandom noise (PN) code;
first combining means for combining said frame of modulation symbol data and said first PN code, and generating an output frame of first PN spread data;
randomizer logic means responsive to said first PN code and an indication of a data rate of said frame variable rate digital data for generating a mask signal; and
filter means for responsive to said mask signal for filtering out portions of said first PN spread data in said frame of first PN spread data.
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Abstract
A method and system, for use in a communication system in which data is transmitted in data frames of a predetermined time duration, for the positioning of the data within the data frames for transmission. A computation circuit computes according to the deterministic code a pseudorandom position for the data within each data frame. A positioning circuit positions the data within each data frame in the computed position.
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Citations
76 Claims
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1. A spread spectrum modulator for modulating variable rate digital data generated in data frames of a predetermined time duration with each frame of data having a number of data bits which is a predetermined multiple of data bits in a frame of a least number of data bits, comprising:
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encoder means for receiving and convolutionally encoding a frame of variable rate digital data, and generating a frame of symbol data with said symbol data in a first ordered sequence; interleaver means for reordering said symbol data in said frame and generating said frame of symbol data in a second ordered sequence, and if said frame of symbol data corresponds to a frame of variable rate digital data having a number of data bits less than a frame maximum of data bits said interleaver means generating said symbol data and a predetermined number of repeats of said symbol data in said frame of symbol data in said second ordered sequence to generate a predetermined frame maximum number of symbols in said frame of sequence symbol data in said second ordered sequence; symbol encoder means for determining from a value of each one of consecutive portions of said frame of symbol data in said second ordered sequence an modulation symbol of a set of modulation symbols, and generating an output frame of function data; first spreading means for generating a first pseudorandom noise (PN) code; first combining means for combining said frame of modulation symbol data and said first PN code, and generating an output frame of first PN spread data; randomizer logic means responsive to said first PN code and an indication of a data rate of said frame variable rate digital data for generating a mask signal; and filter means for responsive to said mask signal for filtering out portions of said first PN spread data in said frame of first PN spread data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined data capacity, comprising:
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interleaver means for receiving said data packet, and if said variable rate data packet is less than said frame data capacity ordering the bits of said data packet in said data frame in accordance with a pseudorandom ordering signal to generate said data frame; randomizing logic for generating, in accordance with a pseudorandom code, said pseudorandom ordering signal; spread spectrum modulation means for receiving said data frame and spread spectrum modulating said data frame; and transmitter for transmitting said spread spectrum modulated data frame. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined data capacity, comprising:
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interleaver means for receiving said data packet, and if said data packet is less than said data capacity generating repeated copies of bits in said data packet and inserting said copies in said data frame; spread spectrum modulation means for spread spectrum modulating said data frame; randomizing logic for generating, in accordance with a pseudorandom code, a pseudorandom gating signal; and transmitter for selectively transmitting bits of said data frame in accordance with said pseudorandom gating signal. - View Dependent Claims (15, 16, 17, 18)
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19. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of data packet bits in a data frame of a predetermined data capacity, comprising:
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interleaver means for receiving said data packet, and if said data packet is less than said data capacity generating a copy of said data packet bits in said data packet and inserting said copy of said data packet bits in said data frame; filtering means for receiving said data frame and filtering out a portion of said data packet bits and said copy of said data packet bits from said data frame in accordance with a pseudorandom filtering signal; spreading means for spread spectrum modulating said filtered data frame; and transmitter means for transmitting said spread spectrum modulated data frame. - View Dependent Claims (20, 21, 22, 23, 24)
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25. In a spread spectrum transmitter, a method for spread spectrum modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined data capacity, comprising:
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receiving said data packet; ordering the bits of said data packet in said data frame in accordance with a pseudorandom ordering signal if said variable rate data packet is less than said frame data capacity; generating in accordance with a pseudorandom code, said pseudorandom ordering signal; spread spectrum modulating said data frame; and transmitting said spread spectrum modulated data frame. - View Dependent Claims (26, 27, 28, 29)
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30. In a spread spectrum transmitter, a method for spread spectrum modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined frame data capacity, comprising:
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receiving said data packet; generating at least one copy of said bits in said data packet if said variable rate data packet is less than said frame data capacity; combining said at least one copy of said data packet bits and said data packet bits to generate said data frame; spread spectrum modulating said data frame; generating, in accordance with a pseudorandom code, a pseudorandom gating signal; and selectively transmitting bits of said data frame in accordance with said pseudorandom gating signal. - View Dependent Claims (31, 32, 33, 34)
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35. In a spread spectrum transmitter, a method for spread spectrum modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined frame data capacity, comprising the steps of:
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receiving said data packet; generating an additional set of said bits in said data packet if said variable rate data packet is less than said frame data capacity; combining said additional set of said data packet bits and said data packet bits to generate said data frame; filtering out a sub-set of bits of said data packet bits and said additional set of of said data packet bits from said data frame in accordance with a pseudorandom filtering signal; generating said pseudorandom filtering signal in accordance with a pseudorandom code; spread spectrum modulating said filtered data frame; and transmitting said spread spectrum modulated data frame. - View Dependent Claims (36, 37, 38, 39)
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40. A spread spectrum transmitter for spread spectrum modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined data capacity, comprising:
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an interleaver having a first input for receiving said data packet and an output for generating said data frame and having a second input; a data burst randomizer having an output coupled to said interleaver second input; a spread spectrum modulator having an input coupled to said interleaver output and having an output; and a transmitter having an input coupled to said spread spectrum modulator output and having an output. - View Dependent Claims (41, 42, 43, 44)
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45. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined frame data capacity, comprising:
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an interleaver having an input port for receiving said data packet and having an output port to generate said data frame consisting of a first instance of said bits of said data packet and a second instance of said bits of said data packet; a spread spectrum modulator having an input coupled to said interleaver output and having an output; a data burst randomizer having an output; and transmitter having a first input coupled to said spread spectrum modulator output and a second input coupled to said data burst randomizer output and having an output. - View Dependent Claims (46, 47, 48, 49)
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50. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined data capacity, comprising:
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an interleaver having an input for receiving said data packet and output for generating a data frame comprising first instance of said data packet bits and a second instance of said data packet bits; a data burst randomizer having an output; a filter having a first input coupled to said interleaver output and a second input coupled to said data burst randomizer output and having an output; a spread spectrum modulator coupled to said filter output and having an output; and transmitter means having an input coupled to said spread spectrum modulator output and having an output. - View Dependent Claims (51, 52, 53, 54)
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55. A spread spectrum modulator for modulating variable rate digital data generated in data frames of a predetermined time duration with each frame of data having a number of data bits which is a predetermined multiple of data bits in a frame of a least number of data bits, comprising:
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an encoder for receiving and convolutionally encoding a frame of variable rate digital data, and generating a frame of symbol data with said symbol data in a first ordered sequence; an interleaver for reordering said symbol data in said frame and generating said frame of symbol data in a second ordered sequence, wherein if said frame of symbol data corresponds to a frame of variable rate digital data having a number of data bits less than a frame maximum of data bits, said interleaver means generating said symbol data and a predetermined number of repeats of said symbol data in said frame of symbol data in said second ordered sequence to generate a predetermined frame maximum number of symbols in said frame of sequence symbol data in said second ordered sequence; a symbol encoder for determining from a value of each one of consecutive portions of said frame of symbol data in said second ordered sequence an modulation symbol of a set of modulation symbols, and generating an output frame of function data; a PN code generator for generating a first pseudorandom noise (PN) code; a first combiner for combining said frame of modulation symbol data and said first PN code, and generating an output frame of first PN spread data; a randomizer logic responsive to said first PN code and an indication of a data rate of said frame variable rate digital data for generating a mask signal; and a filter for responsive to said mask signal for filtering out portions of said first PN spread data in said frame of first PN spread data. - View Dependent Claims (56, 57, 58, 59, 60, 61)
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62. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of bits in a data frame of a predetermined frame data capacity, comprising:
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interleaver means for receiving said data packet, and if said variable rate data packet has fewer bits than said frame data capacity generating additional sets of said bits in said data packet to generate a repetition frame; spreader means for spread spectrum spreading said repetition frame thereby generating a spread spectrum modulated frame; and transmitter means for selectively transmitting a sub-set of bits of said spread spectrum modulated data frame. - View Dependent Claims (63, 64, 65, 66)
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67. A spread spectrum transmitter for modulation and transmission of a data packet of a variable number of data packet bits in a data frame of a predetermined frame data capacity, comprising:
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an interleaver having an input port for receiving said data packet and having an output port for generating at least one copy of said data packet bits; a spread spectrum modulator having an input port coupled to said interleaver output port and having an output port; and a gating transmitter having an input port coupled to said spread spectrum spreader output port and having an output port. - View Dependent Claims (68, 69, 70, 71)
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72. In a spread spectrum transmitter, a method for transmitting data via a data frame having a maximum data capacity and a transmission time period comprising the steps of:
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(a) receiving a data packet; and (b) transmitting portions of said data packet at pseudo-random times within said transmission time period until a single copy of said data packet has been transmitted. - View Dependent Claims (73, 74, 75, 76)
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Specification