Patent ID: 9729220
Date: 2017-08-08
CPC Classifications: H04B

Claim:
1. A single-carrier-modulation communication system for transmitting data over a wireless link, the communication system comprising: on a first side of a wireless link one single-carrier-modulation receiver associated with a single antenna; on a second side of said wireless link a plurality of antennas and a plurality of single-carrier-modulation transmitters, each one of the plurality of transmitters associated with one of said plurality of antennas, the transmitters each further associated with a pre-coding filter; and said plurality of transmitters are arranged to each transmit same data via a respectively associated pre-coding filter and said associated antenna, using said pre-coding filters to perform beam-forming to said one receiver; in which: each one of said plurality of transmitters comprises a pre-coding filter; and parameters defining at least one of said pre-coding filters are designed to be updated as follows: obtaining impulse response parameters for each one of a plurality of transmission path sections associated with each one of said plurality of transmitters, wherein said transmission path sections comprise a pre-coding filter associated with said one of said plurality of transmitters and a wireless link from said one of said plurality of transmitters to a receiver; evaluating a center of each of the components of a received signal; obtaining a differential delay between a signal of a reference transmitter and each one of a plurality of other signals associated with each one of said plurality of transmitters; evaluating a frequency response of a transmission path which includes the pre-coding filter and the wireless link; obtaining a phase of a line-of-sight component for each of the transmission paths; evaluating a differential phase shift of each one of a plurality of other frequency responses associated with each one of said plurality of transmitters with respect to said frequency response of said reference transmitter; and updating a phase of frequency responses except for said line-of-sight frequency response by: subtracting a phase difference from said line-of-sight component; and compensating for said differential delay by adding a phase shift of 2πf·τ, where τ denotes a differential time delay and f denotes a baseband frequency, to said frequency responses except for said line-of-sight frequency response.