A man who used a shoelace to strangle a refugee from Afghanistan will spend at least six years in prison for attempted murder.

Key points: Abdolhadi Moradi was attacked when he was walking along Salisbury Highway

Abdolhadi Moradi was attacked when he was walking along Salisbury Highway Townsville man David John Pearce was intoxicated when he attempted to kill the refugee

Townsville man David John Pearce was intoxicated when he attempted to kill the refugee The judge could not find a motive for the crime

David John Pearce, 37, was sentenced to 11 years in prison with a non-parole period of six years, for his random attack on Abdolhadi Moradi in Adelaide's north, in January last year.

The South Australian Supreme Court had previously heard that without warning, Pearce attacked Mr Moradi from behind while he was walking along Salisbury Highway, strangling him with a shoelace with such force that his victim was dragged to the ground.

The court heard the attack lasted for up to two minutes until bystanders intervened.

Mr Moradi had told the court his family fled Afghanistan when he was a child and lived in Iran before the United Nations helped them relocate to Australia.

He said that he was happy and excited to be in Australia as he had a safe place to live, but that now, he and his family continued to live in fear after the attack.

Justice Sam Doyle conceded the non-parole period was "relatively low", but he accepted Pearce's remorse and contrition for the attack.

Justice Doyle said he could not find a motive and it was fortunate Mr Moradi survived.

Mr Moradi said he continued to live in fear for his safety. ( Supreme Court/SA Police )

"This was not a fleeting episode of strangulation," Justice Doyle said.

"Fortunately, the victim has not suffered any serious or permanent serious harm.

"However, not surprisingly given the unprovoked, sudden and violent nature of the attack, the incident has had a significant, continuing psychological impact on Mr Moradi."

Justice Doyle said Mr Moradi and his family continued "to live in fear for their safety".

"This is particularly tragic given he and his family had only recently fled from the dangers they faced while living in Afghanistan and Iran, in the hope of establishing a safe life in Australia," he said.

David John Pearce was born in Townsville. ( Supreme Court/SA Police )

Pearce was born in Townsville and has a family there.

Justice Doyle said if Pearce took steps to deal with a pattern of substance abuse, he had a reasonable prospect of rehabilitation.

"Your counsel has proffered an apology to Mr Moradi on your behalf … and you acknowledge that [he] is a completely innocent victim of your violence."

During the trial, prosecution submitted the possibility that Pearce had wanted to carry out a racially-motivated killing, but Justice Doyle said he could not reach that conclusion beyond reasonable doubt.