Method and device for modulating with Zadoff-Chu sequences
AssigneeTernwaves
InventorJean Canonici
Life of this patent
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Abstract
A method and device for modulating with Zadoff-Chu sequences. Each K-ary symbol to be transmitted is converted into a Zadoff-Chu sequence of preset length N and of preset root r, and the frequency offset q of which is dependent on the K-ary symbol. Various root values may be used to separate distinct uplink and downlink and synchronous or asynchronous communications. The modulating device is implemented in the frequency domain. The invention also relates to a demodulating method and device allowing the K-ary symbols thus transmitted to be recovered. The demodulating device may be implemented in the time domain or frequency domain.
Claims15
A method for modulating a plurality of K-ary symbols to be transmitted over a transmission channel, wherein each K-ary symbol is transformed into a Zadoff-Chu sequence associated with this symbol, said Zadoff-Chu sequence being of length N, root r and frequency offset q where N is a positive integer such that log2 N≥K, r is an integer such that r >1 and prime to N, q is a relative integer, and that any two K-ary symbols of said plurality are associated with Zadoff-Chu sequences having distinct frequency offsets, each K-ary symbol being modulated in the form of a sequence, of length greater than or equal to 2K, of consecutive complex elements of the Zadoff-Chu sequence associated with said K-ary symbol,
- wherein the distinct frequency offsets for the Zadoff-Chu sequence are assigned distinctively for a successive transmission of respective distinct K-ary symbols on the transmission channel.
A modulation device to modulate a plurality of K-ary symbols to be transmitted over a transmission channel, comprising a binary to decimal converter transforming the bits K of each K-ary symbol into a distinct integer value, and a Zadoff-Chu sequence generator, having as input parameters a sequence length N and a root r such as integer r,r >1 and prime to N, as well as a frequency offset q,q being a relative integer, said generator generating, for each K-ary symbol, a sequence having a length greater than or equal to 2K, formed by complex elements of a Zadoff-Chu sequence of length N, root r and frequency offset equal to the integer value provided by said binary to decimal converter, said Zadoff-Chu sequence generator being configured so that any two K-ary symbols of said plurality are associated with Zadoff-Chu sequences having distinct frequency offsets,
- wherein the distinct frequency offsets for the Zadoff-Chu sequence are assigned distinctively for a successive transmission of respective distinct K-ary symbols on the transmission channel.
Dependencies are inferred from the claim text.