US5828695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
QAM system in which the constellation is modified in accordance with channel quality
Assignee: BlackBerry Ltd
•
Filing: 1992-06-02
•
Granted: 1998-10-27
•
Expires: 2012-06-02
Abstract
Abstract A radio system is so designed as to allow each of a pair of transceivers to assess the quality of the link, and to modify the signal constellation accordingly. Each transceiver monitors the quality of the channel by assessing the strength of the received signal, or the bit error rate, or both. The system is specifically adapted to time division duplex (TDD) transmission over fast fading channel. In each block of data, the first bit is a QPSK (4QAM) signal, which indicates which constellation is to be used.
Inventors
- 👤 William Timothy Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:37
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/08; H04L1/0001; H04L1/0023; H04L1/0025; H04L1/20; H04L1/0015; H04L1/0019; H04L1/0021
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
A radio system comprising a pair of stations at least one of which has a radio transceiver having; a radio receiver for receiving signals from the other station; means for assessing a quality of the received radio signals; means for selecting a transmission modulation state on the basis of the assessment of the quality of the received signals; a radio transmitter for transmitting signals to the other station using a modulation scheme having a plurality of modulation states; means for adjusting the transmitting state of the radio transmitter to be the selected modulation state; and signalling means for including in the signals to be transmitted to the other station an indication of the selected modulation state.
Claim 2
Dependent Claim
116 words
A radio system comprising a pair of stations at least one of which has a radio transceiver having; a radio receiver for receiving signals from the other station; means for assessing a quality of the received radio signals; means for selecting a transmission modulation state on the basis of the assessment of the quality of the received signals; a radio transmitter for transmitting signals to the other station using a modulation scheme having a plurality of modulation states; means for adjusting the transmitting state of the radio transmitter to be the selected modulation state; and signalling means for including in the signals to be transmitted to the other station an indication of the selected modulation state.
Claim 3
Dependent Claim
40 words
A radio system as claimed in claim 1 wherein the signalling means has means for adjusting the modulation state of the radio transmitter to transmit the indication of the selected modulation state in a predetermined one of the modulation states.
Claim 4
Dependent Claim
18 words
A radio system as claimed in claim 1 wherein the radio system operates using time division duplex operation.
Claim 5
Dependent Claim
19 words
A radio system as claimed in claim 1, wherein the modulation scheme of the transmitter is quadrature amplitude modulation.
Claim 6
Dependent Claim
35 words
A radio system as claimed in claim 1 wherein the means for assessing the quality of the received radio signals assess either or both the received signal strength or bit error rate of those signals.
Claim 7
Dependent Claim
16 words
A radio system as claimed in claim 1 wherein each station has a said radio transceiver.
Claim 8
Dependent Claim
56 words
A radio transceiver for the transmission and reception of digital signals wherein a transmitter of the transceiver varies the number of binary digits encoded onto each symbol for transmission in accordance with measured received signal strength, the measured bit error rate (BER) or some combination of these which are received by a receiver of said transceiver.
Claim 9
Dependent Claim
56 words
A radio transceiver for the transmission and reception of digital signals wherein a transmitter of the transceiver varies the number of binary digits encoded onto each symbol for transmission in accordance with measured received signal strength, the measured bit error rate (BER) or some combination of these which are received by a receiver of said transceiver.
Claim 10
Dependent Claim
44 words
A radio transceiver comprising a transmitter and a receiver wherein the signal strength received by said receiver is averaged over a predetermined time period and the number of bits/symbol to be used in subsequent transmissions by said transmitter is determined according to this average.
Claim 11
Dependent Claim
44 words
A radio transceiver comprising a transmitter and a receiver wherein the signal strength received by said receiver is averaged over a predetermined time period and the number of bits/symbol to be used in subsequent transmissions by said transmitter is determined according to this average.
Claim 12
Dependent Claim
51 words
A radio transceiver comprising a transmitter and a receiver wherein errors in decoded digital signals received by said receiver are identified using an error detection system, and the number of bits/symbol to be used in subsequent transmissions by said transmitter is based on the number and distribution of the errors detected.
Claim 13
Dependent Claim
51 words
A radio transceiver comprising a transmitter and a receiver wherein errors in decoded digital signals received by said receiver are identified using an error detection system, and the number of bits/symbol to be used in subsequent transmissions by said transmitter is based on the number and distribution of the errors detected.
Claim 14
Dependent Claim
45 words
A radio system according to claim 1 wherein the radio communication is bi-directional but instantaneously uni-directional, and said signals comprise data placed in packets or blocks wherein the initial symbols in each block are reserved for signalling the number of bits/symbol used in the block.
Claim 15
Dependent Claim
91 words
A radio transceiver comprising: a radio receiver for receiving radio signals; means for assessing a quality of the received radio signals; means for selecting a transmission modulation state on the basis of the assessment of the quality of the received signals; a radio transmitter for transmitting signals using a modulation scheme having a plurality of modulation states; means for adjusting the transmitting state of the radio transmitter to be the selected modulation state; and signalling means for including in the signals to be transmitted an indication of the selected modulation state.
Claim 16
Dependent Claim
91 words
A radio transceiver comprising: a radio receiver for receiving radio signals; means for assessing a quality of the received radio signals; means for selecting a transmission modulation state on the basis of the assessment of the quality of the received signals; a radio transmitter for transmitting signals using a modulation scheme having a plurality of modulation states; means for adjusting the transmitting state of the radio transmitter to be the selected modulation state; and signalling means for including in the signals to be transmitted an indication of the selected modulation state.
References Cited (Backward Citations)
US4462105A
Cited
US4495619A
Cited
EP0154565A2
Cited
US4677625A
Cited
US4780883A
Cited
US4945549A
Cited
US4797898A
Cited
US5054036A
Cited
US5289459A
Cited
US4852090A
Cited
US4888792A
Cited
US4903324A
Cited
US4899367A
Cited
US5123008A
Cited
US4956851A
Cited
US4937844A
Cited
US5117423A
Cited
US5063571A
Cited
US5134635A
Cited
US5150384A
Cited
US5222247A
Cited
US5276686A
Cited
US5170413A
Cited
US5233629A
Cited
US5210770A
Cited
US5263052A
Cited
US5363408A
Cited
US5282222A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-26 | 2002-04-27 | 2002-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-26 | 2006-04-27 | 2006-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-26 | 2010-04-27 | 2010-10-27 | $7700.00 | Window Closed / Lapsed |