Method for extracting a variable reference pattern
AssigneeWavecom
InventorsMichel Alard, Nathalie Goudard
Life of this patent
Estimating the term…
Abstract
A method is provided for extracting a sequence of pilot symbols enabling to estimate the transfer function of a transmission channel. At least a radiocommunication device communicates through the channel with a remote station, the latter regularly delivering to the radiocommunication device a reference pattern. The structure of the reference pattern is variable, depending on at least one characteristic of the transmission channel.
Claims42
A method for extracting a sequence of pilot symbols allowing to estimate the transfer function of a transmission channel, at least one radio communication device communicating through the channel with a remote station,
- the station regularly inserting a reference pattern in a signal transmitted to the radio communication device, said reference pattern having a structure in a time-frequency space defined at least by a spacing in time between two pilot symbols (Nt) and a spacing in frequency between two pilot symbols (Nf),
- wherein at least one feature of the structure of said reference pattern, said features comprising the value of said spacing in time between two pilot symbols (Nt) and/or of said spacing in frequency between two pilot symbols (Nf) is variable during transmission of said signal, the method comprising:
- receiving said signal;
- extracting a current reference pattern from said signal;
- analyzing said current reference pattern, to provide at least one characteristic of the transmission channel belonging to the group consisting of a maximum Doppler frequency and a maximum delay spread of the channel;
- and
- determining features of a next reference pattern, comprising the value of said spacing in time between two pilot symbols (Nt) and/or of said spacing in frequency between two pilot symbols (Nf), as a function of said at least one characteristic of the transmission channel.
A method for extracting a sequence of pilot symbols allowing to estimate the transfer function of a transmission channel, at least one radio communication device communicating through the channel with a remote station,
- the remote station regularly inserting a reference pattern in a signal transmitted to the radio communication device, said reference pattern having a structure in a time-frequency space defined at least by a spacing in time between two pilot symbols (Nt) and a spacing in frequency between two pilot symbols (Nf),
- the method comprising:
- receiving said signal;
- extracting a culTent reference pattern from said signal;
- analyzing said current reference pattern, to determine at least one characteristic of the transmission channel belonging to the group consisting of a maximum Doppler frequency and a maximum delay spread of the channel;
- and
- determining a next structure of said reference pattern having at least one next feature of a reference pattern, comprising the value of said spacing in time between two pilot symbols (Nt) and/or of said spacing in frequency between two pilot symbols (Nf), as a function of said at least one characteristic of the transmission channel;
- extracting a next reference pattern having said next structure.
A radio communication device communicating through a channel with a remote station, and receiving from said remote station a signal in which a reference pattern is regularly inserted, said reference pattern having a structure in a time-frequency space defined at least by a spacing in time between two pilot symbols (Nt) and a spacing in frequency between two pilot symbols (Nf),
- wherein said radio communication device comprises:
- means for receiving said signal;
- means for extracting a current reference pattern from said signal;
- means for analyzing said current reference pattern, to determine at least one characteristic of the transmission channel belonging to the group consisting of a maximum Doppler frequency and a maximum delay spread of the channel;
- means for determining a next structure of said reference pattern having at least one next feature of a reference pattern, comprising the value of said spacing in time between two pilot symbols (Nt) and/or of said spacing in frequency between two pilot symbols (Nf), as a function of said at least one characteristic of the transmission channel;
- and
- means for extracting a next reference pattern having said next structure.
A remote station communicating through a channel with at least one radio communication device, said remote station sending a signal in which a reference pattern is regularly inserted, said reference pattern having a structure in a time-frequency space defined at least by a spacing in time between two pilot symbols (Nt) and a spacing in frequency between two pilot symbols (Nf),
- wherein said remote station comprises:
- means for inserting a current reference pattern in said signal;
- means for obtaining at least one characteristic of the transmission channel belonging to the group consisting of a maximum Doppler frequency and a maximum delay spread of the channel;
- means for determining a next structure of said reference pattern having at least one next feature of a reference pattern, comprising the value of said spacing in time between two pilot symbols (Nt) and/or of said spacing in frequency between two pilot symbols (Nf), as a function of said at least one characteristic of the transmission channel;
- and
- means for inserting a next reference pattern having said next structure in said signal.
Dependencies are inferred from the claim text.