What is claimed is:
1. A method of correcting error bits of a data signal inputted via a radio channel in a time division multiple access system, comprising the steps of:
determining at least one of a RSSI information and a phase error information at every symbols when the data signal is received;
judging whether or not the determined information falls within a range of a predetermined value indicating deterioration of a line quality;
determining one bit outside the range as an error bit; and
reversing the error bit.
2. A method as claimed in claim 1, comprising further the following step:
using a BCH code error correction together,
a predetermined BCH error correction code being used for a BCH coded data signal in the BCH code error correction.
3. A method as claimed in claim 2, wherein:
the BCH code error correction is carried out by using the predetermined error correction code after the bit correction is performed by determining as the error bit.
4. A method of correcting error bits of a BCH coded data signal in a time division multiple access system, comprising the steps of:
determining at least one of a RSSI information and a phase error information at every symbols when the data signal is received;
correcting an error of a BCH code by using a predetermined error correction code;
checking the determined information when a CRC error is detected in a predetermined CRC error detection;
judging whether or not the determined information falls within a range of a predetermined value indicating deterioration of a line quality;
determining one bit outside the range as an error bit;
reversing the error bit; and
correcting another error of the BCH code by using the predetermined error correction code.
5. A circuit for correcting error bits of a data signal inputted via a radio channel in a time division multiple access system, comprising:
an information collecting portion which determines a line quality at every symbols by using at least one of a RSSI information and a phase error information when the data signal is received; and
an estimate bit correction portion which judges whether or not the determined information falls within a range of a predetermined value indicating deterioration of the line quality and which determines one bit outside the range as an error bit and which reverses the error bit.
6. A circuit as claimed in claim 4, further comprises:
a BCH error correction portion which corrects an error of a BCH code by using a predetermined BCH error correction code for a BCH coded data signal.
7. A circuit as claimed in claim 6, wherein:
the BCH error correction portion is given with a bit-corrected data signal by the estimate bit correction portion.
8. A circuit for correcting error bits of a BCH coded data signal in a time division multiple access system, comprising:
a BCH error correction portion which corrects an error of a BCH code by using a predetermined error correction code;
an information collecting portion which determines a line quality at every symbols using at least one of a RSSI information and a phase error information when the data signal is received; and
an estimate bit correction portion which judges whether or not the determined information falls within a range of a predetermined value indicating deterioration of the line quality and which determines one bit outside the range as an error bit and which reverses the error bit;
the estimation bit correction portion supplying the corrected data signal into the BCH error correction portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A brake master cylinder (10) for a motor vehicle, of the type which comprises a practically axial body (12) inside a bore (14) of which is slidably mounted at least one axial piston (16, 18) which can be actuated by a driver of the vehicle between a rear position of rest and a forward position of applying a braking force, of the type in which the bore (14) comprises two sealing means, front (26, 28) and rear (30, 32), which are interposed between the piston (16, 18) and the bore (14), the front sealing means (26, 28) delimiting within the bore (14) a rear supply chamber (34, 38) and a front pressure chamber (36, 40), of the type in which the body (12) comprises a radial supply duct (42, 48) which connects an external reservoir of hydraulic fluid to the rear supply chamber (34, 38) and which opens between the two sealing means (26, 28, 30, 32) of the type in which the body (12) comprises a supply drilling (50, 52) for a braking circuit which opens into the front pressure chamber (36, 40), of the type which comprises means (106, 108) placing the front pressure chamber (36, 40) and the rear supply chamber (34, 38) in communication, which means are able to be inhibited by the piston (16, 18) when it is moved axially forwards towards its position of application so as to isolate the front pressure chamber (36, 40) from the rear supply chamber (34, 38) and thus make it possible for a braking pressure to be established in the front pressure chamber (36, 40), of the type in which the front sealing means (26, 28) is able to allow hydraulic fluid to pass as the piston (16, 18) retreats towards its position of rest, characterized in that the bore (14) comprises a front portion (120, 124) for guiding the piston (16, 18), arranged forward of the front sealing means (26, 28) which comprises at least one groove (128) which establishes communication between the front chamber (36, 40) and the front sealing means (26, 28) so as to allow, as the piston (16, 18) retreats towards its position of rest, the resupply of the radial supply duct (42, 48) and of the reservoir.
2. The master cylinder (10) according to claim 1, characterized in that the bore (14) comprises at least one rear portion (122, 126) for guiding the piston, which is arranged between the front sealing means (26, 28) and the radial supply duct (42, 48), and which comprises at least one groove (130) which establishes communication between the front sealing means (26, 28) and the radial duct (42, 48) so as to allow, as the piston (16, 18) retreats towards its position of rest, the resupply of the radial supply duct (42, 48) and of the reservoir.
3. The master cylinder (10) according to claim 2, characterized in that the grooves (128, 130) are helical.
4. The master cylinder according to claim 3, characterized in that each portion, front (120, 124) andor rear (122, 126), comprises a number of grooves (128, 130).
5. The master cylinder (10) according to claim. 4, characterized in that the front (120, 124) and rear (122, 126) guide portions consist respectively of front (120, 124) and rear (122, 126) annular bearing surfaces which project into the bore (14) and each of which has an inside diameter (D) practically corresponding to that of the piston (16, 18).
6. The master cylinder (10) according to claim 5, characterized in that the front sealing means consist of a front seal (26, 28) which is mounted in a groove (110, 112) of the body (12) and an interior peripheral lip of which, arranged in contact with the piston (16, 18), is able to lift the piston (16, 18) when it returns from its position of application to its position of rest, so as to allow the hydraulic fluid, by flowing between the bore (14) and the piston (16, 18), to resupply the radial supply duct (42, 48) and the reservoir.
7. The master cylinder (10) according to claim 6, characterized in that the piston (16, 18) comprises, at its end, an external elastic ring (142, 144) which is capable, when the piston (16, 18) is in the position of rest, of coming into contact with a front shoulder face of the front annular bearing surface (120, 124) to form an end stop.
8. The master cylinder (10) according to claim 7, characterized in that the piston (16, 18) is returned elastically to its rear position of rest by a spring (20, 24).
9. The master cylinder (10) according to claim 8, characterized in that it is a master cylinder of the tandem type which comprises, from the rear forwards, two pistons, primary (16), 18) and secondary, which delimit, within the bore of the body, a primary (34) and a secondary (38) supply chamber, and a primary (36) and a secondary (40) pressure chamber, the primary piston (16) being returned elastically to its rear position of rest by a spring (24) bearing between a rear face (25) of the secondary piston (18) and a front face (29) of the primary piston (16).