US5745480A — Multi-rate wireless communications system

Claim 1

Independent Claim 121 words

A multi-rate communication system having a base station communicating with a plurality of active user terminals, and a requesting user terminal, each of said user terminals having a transmitter and a receiver, said base station comprising: means for receiving a message from said requesting user terminal to said base station, said requesting user terminal requesting communication using a desired data rate and a desired quality of service QOS parameter; means for determining a suitable data rate, a suitable QOS, and expected received signal power for said requesting user terminal based on said desired data rate and said desired QOS; and means for communicating said suitable data rate, said suitable QOS, and said expected received signal power to said requesting user terminal.

Claim 2

Dependent Claim 121 words

A multi-rate communication system having a base station communicating with a plurality of active user terminals, and a requesting user terminal, each of said user terminals having a transmitter and a receiver, said base station comprising: means for receiving a message from said requesting user terminal to said base station, said requesting user terminal requesting communication using a desired data rate and a desired quality of service QOS parameter; means for determining a suitable data rate, a suitable QOS, and expected received signal power for said requesting user terminal based on said desired data rate and said desired QOS; and means for communicating said suitable data rate, said suitable QOS, and said expected received signal power to said requesting user terminal.

Claim 3

Dependent Claim 88 words

The system of claim 1 wherein said means for determining further comprising: means for computing a requested power budget for said requesting user terminal based on said desired data rate and said desired QOS; means for computing a combined power budget for said active user terminals; and means for selecting a suitable data rate as equal to said desired data rate and a suitable QOS as equal to said desired QOS when a sum of said requested power budget and said combined power budget is less than one.

Claim 4

Dependent Claim 66 words

The system of claim 2 wherein said means for determining further comprising means for determining an available power budget for said requesting user terminal based on said desired data rate and said desired QOS when a sum of said requested power budget and said combined power budget is greater than one, said suitable data rate and said suitable QOS being related to said available power budget.

Claim 5

Dependent Claim 75 words

The system of claim 2 wherein said requesting user terminal communicates with said base station using, a device having, a fixed chip rate (C) and requiring a ratio α of a signal component and an interference component, where said a is determined by said desired QOS, said means for computing said requested power budget (H) calculating said H from: H=α/(PG+α); where PG=C/R and said R is said desired data rate of said requesting user terminal.

Claim 6

Dependent Claim 65 words

The system of claim 4 wherein said requesting user terminal further comprises: means for calculating propagation loss in a direction from base-station to said requesting user terminal; means for calculating nominal transmit power based on said propagation loss and said expected signal power communicated by said base station to said requesting user terminal; and means for controlling transmit power based on said nominal transmit power.

Claim 7

Dependent Claim 79 words

The system of claim 4 wherein said means for computing a combined power budget computes a sum of a power budget (H i ) of each active user terminal, said power budget H i being computed from: H.sub.i =α.sub.i /(PG.sub.i +α.sub.i); where PG i =C/R i and R i is a data rate of said ith active user terminal, and α i is a ratio of a signal component and an interference component of an ith active user terminal.

Claim 8

Dependent Claim 80 words

The system of claim 6 wherein said base station further comprises: means for calculating nominal transmit power to each said active user terminal and said requesting terminal such that for each of said active and requesting user terminals the ratio of transmit power to total transmit power exceeds said power budget H i ; and a variable gain unit for controlling transmit power to each said active user terminal and said requesting terminal based on said calculated nominal transmit power.

Claim 9

Dependent Claim 21 words

The system of claim 3 wherein said available power budget (H') is substantially equal to one minus said combined power budget.

Claim 10

Dependent Claim 54 words

The system of claim 8 wherein said requesting user terminal communicates with said base station using a device having a fixed chip rate (C) and requiring a ratio α of a signal component to an interference component, said means for computing said suitable data rate (R') calculating said R' from: PG'=α/((1/H')-1), and R'=C/PG'. 10.

Claim 11

Dependent Claim 63 words

The system of claim 8 wherein said requesting user terminal communicates with said base station using a device having a fixed chip rate (C) and desired data rate R, said means for computing said suitable QOS (QOS') calculating said QOS' from: PG=C/R, and α'=PG/((1/H')-1), where α' is a ratio of a signal component to an interference component and is related to said QOS'.

Claim 12

Dependent Claim 69 words

The system of claim 8 wherein said requesting user terminal communicates with said base station using a device having a fixed chip rate (C), said means for computing said suitable data rate (R') and said suitable QOS (QOS') calculating said R' and said QOS' from: R'=C/PG' and α'=PG'/((1/H')-1); where α' is a ratio of a signal component to an interference component and is related to said QOS', and 1≦PG'≦C/R.

Claim 13

Dependent Claim 37 words

The system of claim 8 wherein said available power budget H' is substantially equal to one minus said combined power budget minus δ, where δ represents a fraction of total received power that comes from narrowband interferers.

Claim 14

Dependent Claim 24 words

The system of claim 1 wherein said base station communicates with said active and said requesting user terminals using a frequency division duplexing arrangement.

Claim 15

Dependent Claim 24 words

The system of claim 1 wherein said base station communicates with said active and said requesting user terminals using a time division duplexing arrangement.

Claim 16

Dependent Claim 30 words

The system of claim 1 wherein said means for communicating further comprises means for transmitting over a separate signal channel jointly used by said active and said requesting user terminals.

Claim 17

Dependent Claim 210 words

The base station of claim 1 further comprising a plurality of transmitter units, one for each of said user terminals, each of said transmitter units comprising: a framer unit for converting input user bit stream and control bit stream into the closest of one of a plurality of negotiated bit rates that is equal to the product of 2 L and R, where L=1,2, . . . n and R is a minimum bit rate supported by said system; an encoder unit for generating, I and Q symbol streams each at a symbol rate equal to a product of 2.sup.(L-1) and R; a unique code for spreading said I and Q symbol streams to a fixed chip rate I and Q chip stream; a variable gain unit for scaling said I and Q chip streams; a first combiner for combining said scaled I chip stream generated by said plurality of transmitter units of all said user terminals; a second combiner for combining said scaled Q chip stream generated by said plurality of transmitter units of all said user terminals; a quadrature modulator for modulating said combined I and Q chip streams generated by said first and said second combiners; and a variable gain power amplifier for amplifying said modulated signal.

Claim 18

Dependent Claim 14 words

The base station of claim 16 wherein said encoder is a general MPSK encoder.

Claim 19

Dependent Claim 14 words

The base station of claim 16 wherein said encoder is a differential MPSK encoder.

Claim 20

Dependent Claim 14 words

The base station of claim 16 wherein said encoder is a general QAM encoder.

Claim 21

Dependent Claim 22 words

The base station of claim 16 wherein separate unique spreading codes are used to generate said I and said Q symbol streams.

Claim 22

Dependent Claim 134 words

The base station of claim 1 further comprises a plurality of receiver units, one for each of said user terminals, each of said receiver units comprising: a variable automatic gain controller for amplifying a received signal; a quadrature demodulator for demodulating said amplified signal into an I and a Q chip streams; a unique code for de-spreading, said I and Q chip streams to an I and Q symbol stream; a first integrator for integrating said I symbol stream over a symbol duration; a second integrator for integrating said Q symbol stream over said symbol duration; a decoder unit for generating a received bit stream based on said integrated I and Q symbol streams; and a deframer for generating an output bit stream and a control bit stream based on said received bit stream.

Claim 23

Dependent Claim 14 words

The base station of claim 21 wherein said decoder is a general MPSK encoder.

Claim 24

Dependent Claim 14 words

The base station of claim 21 wherein said decoder is a differential MPSK encoder.

Claim 25

Dependent Claim 14 words

The base station of claim 21 wherein said decoder is a general QAM encoder.

Claim 26

Dependent Claim 22 words

The base station of claim 21 wherein separate unique de-spreading codes are used to generate said I and said Q symbol streams.

Claim 27

Dependent Claim 137 words

The system of claim 1 wherein each of said transmitters of said plurality of user terminals comprises: a framer unit for converting input user bit stream and control bit stream into the closest of one of a plurality of negotiated bit rates that is equal to the product of 2 L and R, where L=1,2, . . . n and R is a minimum bit rate supported by said system; an encoder unit for generating, I and Q symbol streams each at a symbol rate equal to a product of 2.sup.(L-1) and R; a unique code for spreading said I and Q symbol streams to a fixed chip rate I and Q chip stream; a quadrature modulator for modulating said I and said Q chip streams; and a variable gain power amplifier for amplifying said modulated signal.

Claim 28

Dependent Claim 14 words

The user transmitter of claim 26 wherein said encoder is a general MPSK encoder.

Claim 29

Dependent Claim 14 words

The user transmitter of claim 26 wherein said encoder is a differential MPSK encoder.

Claim 30

Dependent Claim 14 words

The user transmitter of claim 26 wherein said encoder is a general QAM encoder.

Claim 31

Dependent Claim 22 words

The user transmitter of claim 26 wherein separate unique spreading codes are used to generate said I and said Q symbol streams.

Claim 32

Dependent Claim 125 words

The system of claim 26 wherein each of said receivers of said plurality of user terminals comprises: a variable automatic gain controller for amplifying a received signal; a quadrature demodulator for demodulating said amplified signal into an I and a Q chip streams; a unique code for de-spreading said I and Q chip streams to an I and Q symbol stream; a first integrator for integrating, said I symbol stream over a symbol duration; a second integrator for integrating said Q symbol stream over said symbol duration; a decoder unit for generating a received bit stream based on said integrated I and Q symbol streams; and a deframer for generating an output bit stream and a control bit stream based on said received bit stream.

Claim 33

Dependent Claim 14 words

The user receiver of claim 31 wherein said decoder is a general MPSK encoder.

Claim 34

Dependent Claim 14 words

The user receiver of claim 31 wherein said decoder is a differential MPSK encoder.

Claim 35

Dependent Claim 14 words

The user receiver of claim 31 wherein said decoder is a general QAM encoder.

Claim 36

Dependent Claim 22 words

The user receiver of claim 31 wherein said unique de-spreading codes are used to generate said I and said Q symbol streams.

Claim 37

Independent Claim 113 words

A method for a multi-rate wireless communication system having a base station and a plurality of active user terminals to allocate a data rate for a requesting user terminal, said requesting user terminal requesting a desired data rate (R) at a desired quality of service (QOS), said method comprising the steps of: computing a requested power budget for said requesting user terminal based on said desired data rate and said desired QOS; computing a combined power budget for said active user terminals; and granting, by said base station, said desired data rate and said desired QOS when a sum of said requested power budget and said combined power budget is less then one.

Claim 38

Independent Claim 113 words

A method for a multi-rate wireless communication system having a base station and a plurality of active user terminals to allocate a data rate for a requesting user terminal, said requesting user terminal requesting a desired data rate (R) at a desired quality of service (QOS), said method comprising the steps of: computing a requested power budget for said requesting user terminal based on said desired data rate and said desired QOS; computing a combined power budget for said active user terminals; and granting, by said base station, said desired data rate and said desired QOS when a sum of said requested power budget and said combined power budget is less then one.

Claim 39

Dependent Claim 72 words

The method of claim 36 further comprising the steps of: computing an available power budget for said requesting user terminal; determining a suitable data rate and suitable QOS when a sum of said requested power budget and said combined power budget exceeds one, said suitable data rate and said suitable QOS being related to said available power budget; and sending said suitable data rate and suitable QOS to said requesting user terminal.

Claim 40

Dependent Claim 28 words

The method of claim 37 further comprising the step of determining a signal component of said requesting user terminal such that it operates within said available power budget.

Claim 41

Dependent Claim 55 words

The method of claim 36 wherein said wireless communication system has a fixed chip rate (C) and said requesting user terminal requires a ratio α of a signal component to an interference component, said requested power budget (H) being computed from: H=α/(PG+α); where PG=C/R and R is said desired data rate of said requesting terminal.

Claim 42

Dependent Claim 77 words

The method of claim 39 wherein said combined power budget is a sum of a power budget (H i ) of each active user terminal, said power budget H i being, computed from: H.sub.i =α.sub.i /(PG.sub.i +α.sub.i); where PG i =C/R i , and where α i is a ratio of a signal component to an interference component of an ith active user terminal and R i is a bit rate of said ith active user terminal.

Claim 43

Dependent Claim 21 words

The method of claim 37 wherein said available power budget (H') is substantially equal to one minus said combined power budget.

Claim 44

Dependent Claim 44 words

The method of claim 41 wherein said wireless communication system has a fixed chip rate (C) and said requesting user terminal requires a ratio α of a signal component to an interference component, said suitable data rate (R') is computed from: PG'=α/(1/H'-1), and R'=C/PG'.

Claim 45

Dependent Claim 88 words

The method of claim 38 wherein said wireless communication system has a fixed chip rate (C) and said available power budget (H') is substantially equal to one minus said combined power budget, said signal component (S') of said requesting user terminal being computed from: S'=α'I; α'=PG/(1/H'-1) and PG=C/R; where I is an interference component of said requesting user terminal, which in turn is calculated as I=(sum of all S j )/PG, where S j is received near signal power from jth user terminal measured by said base station.

Claim 46

Dependent Claim 23 words

The method of claim 36 further comprising a step of modulating signals of said base station and said active and requesting user terminals.

Claim 47

Dependent Claim 30 words

The method of claim 37 wherein said sending step further comprises a step of transmitting over a separate signal channel jointly used by said active and said requesting user terminals.

Claim 48

Dependent Claim 160 words

The method of claim 36 further comprising the steps, executed by said base station, of: converting a combined user bit stream and a control bit stream to one of a plurality of bit rates that is equal to a product of 2 L and R, where L=1,2, . . . n and R is a minimum bit rate supported by the system; encoding, said converted bit stream into I and Q signals; spreading said I and Q signals by a unique spreading code at a fixed chip rate to generate I and Q fixed rate chip streams; scaling said I and Q fixed rate chip streams for each of said active user terminals to achieve the negotiated QOS; summing said scaled I, Q fixed rate chip streams generated by transmitters of said active user terminals; modulating said summed I and Q fixed rate chip streams to a reverse link frequency; and amplifying said modulated signal using a variable gain amplifier.

Claim 49

Dependent Claim 20 words

The method of claim 46 wherein separate spreading codes are used to generate said I and said Q symbol streams.

Claim 50

Dependent Claim 102 words

The method of claim 46 further comprising the steps, executed by each of a plurality of receiver units in said base station, of: amplifying a received signal; demodulating said amplified signal into an I and a Q chip stream; de-spreading said I and said Q chip streams into an I and an Q symbol stream using a unique code; integrating said I symbol stream over a symbol duration; integrating said Q symbol stream over said symbol duration; decoding a received bit stream based on said integrated I and Q symbol streams; and generating an output bit stream and a control bit stream.

Claim 51

Dependent Claim 20 words

The method of claim 48 wherein separate de-spreading codes are used to generate said I and said Q symbol streams.

Claim 52

Dependent Claim 126 words

The method of claim 36 further comprising the steps, executed by each of said active user terminals, of: converting a combined user bit stream and control bit stream to one of a plurality of bit rates that is equal to a product of 2 L and R, where L=1,2, . . . n and R is a minimum bit rate supported by the system; encoding said combined bit stream into I and Q signals; spreading said I and Q signals by a unique spreading code at a fixed chip rate to generate I and Q fixed rate chip streams; modulating said I and Q fixed rate chip streams to a forward link frequency; and amplifying said modulated signal at a level commanded by said base station.

Claim 53

Dependent Claim 20 words

The method of claim 50 wherein separate spreading codes are used to generate said I and said Q symbol streams.

Claim 54

Dependent Claim 89 words

The method of claim 50 further comprising the steps of: amplifying a received signal; demodulating said amplified signal into an I and a Q chip stream; de-spreading said I and said Q chip streams into an I and an Q symbol stream using a unique code; integrating said I symbol stream over a symbol duration; integrating said Q symbol stream over said symbol duration; decoding a received bit stream based on said integrated I and Q symbol streams; and generating an output bit stream and a control bit stream.

Claim 55

Dependent Claim 20 words

The method of claim 52 wherein separate de-spreading codes are used to generate said I and said Q symbol streams.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-04-27	2001-10-27	2002-04-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-04-27	2005-10-27	2006-04-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-04-27	2009-10-27	2010-04-28	$7700.00	Window Closed / Lapsed

Multi-rate wireless communications system

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag