After subsisting mostly on corn, cabbage and beans for two months while being held on a murder charge in a Kenyan jail, Jimmy Tyson came home to a big welcome on Nicholson Street in Riverdale yesterday, and said he had just one word to describe his feelings.

"Relieved."

The 21-year-old Navy fireman was acquitted Friday in Mombasa of a charge that he murdered a Kenyan woman on the day in April his aircraft carrier, the America, docked in the East African port city on a visit.

By noon yesterday, Tyson, who according to a Kenyan judge had been wrongly identified and had not encountered the victim, was carrying his sea bag down Nicholson Street, past welcome posters and trees festooned with yellow ribbons, into the house where his mother was waiting for him with her eyes full of tears. "I'm a nervous wreck right now," Helen Tyson had said, minutes before her son walked in. He was last home on leave in November.

"You worry with him being in a foreign country," she said of the son who had grown up here and gone to Bladensburg High School. "We knew he was innocent and that he'd be home, it was just a question of when," she said.

Before going inside, Jimmy Tyson received the hugs and handshakes of about a dozen friends and neighbors who were waiting in the sweltering heat to greet him.

Three members of the welcoming party, Tyson's brothers Johnny, 16, and Bobby, 18, and fishing buddy Roger Groomes, 24, who said Tyson was like a brother to him, spent Saturday night camped on the lawn in front of Tyson's home, waiting.

"I was just looking up in the sky to see if I could find an airplane," said Groomes, who said he barely slept.

Their hugs and handshakes dripped with perspiration, but nobody seemed to mind.

Tyson, home on a month's leave, appeared healthy after the successive ordeals of incarceration, trial and homeward journey that included a 2 1/2-hour trip by bus and subway to Nicholson Street from National Airport.

He praised the efforts made by the Navy in his behalf.

In particular he expressed gratitude for the Navy's work in adding milk and potatoes to what he described as the jail diet of corn for breakfast, cabbage for lunch and beans for sup- per.

However, he told a reporter, his potato ration was cut at one time from six a day to just one, and he wrote home to express his dismay. That, he said, explained the legend on one of the posters that adorned his block yesterday. It said:

"1 Potato, 2 Potato, 3 Potato, 4; 5 Potato, 6 Potato, Now You'll Get More."